V 1997 UNIFORM ain [mea VOLUME 2 STRUCTURAL ENGINEERING DESIGN PROVISIONS‘TABLE OF CONTENTS—VOLUME 1 ES Table of Contents—Volume 1 Administrative, Fire- and Life-Safety, and Field Inspection Provisions Effective Use of the Uniform Building Code ........... 1-xvii Chapter § General Building Limitations Section 501 Scope ... Section 502 Premises Initiation Seation S03 Location on Property “1 Section S04 Allowsble Flooe Areas a 1 Seetion SOS Allowable Area Increases 183 Mi Section $06 Maximum Height of Buildings Sample Ordinance for Adoption of the Uniform Building Code, Volumes 1,2 and 3 ........ 1-xix Chapter 1 Administration Section 101 ‘Tile, Purpose and Scape Scotion 102 Unsafe Buildings or Structures 1 1 : Scetion 103 Violations. I ‘and Increases re sd Section 104 Organization and Enforcement ....- Ww Section $07 Mezzanines 8 See eae Th Seaton S08 PevesistveSitotion 34 Se 1 Seon 509 | Gand CO oe Section 107 Fees i 1-4 Chapter 6 ‘Types of Construction ..... . B61 Section 108 Inspections see ES Section 601 Classification of Ail Buildings Section 109 Conia of Occupancy be by Typesof Constuton ad Grrl Reutenens LI Chapter 2 Definitions and Abbreviations a Section 602 ‘Type I Fire-resistive Buildings . . 162 Cuaper 3 Use or Ocupaney Tyg Seton 603. Type Boldngs ane Section 301 Oceupaney Clsif ig —_SetondO4 HREM Bung aeons Eh Sere cd Section 606 Type V Buildings ...........05 1-65 Section 303 Requlrements for Group A Occupancies 1-14 Section 304 Requirements for Group B Occupancies Chapter 7 Fire-resistant Materials and Construction . 1-67 Scetion 305. Requiements for Group E Oceupancies Section 701 Scope cia 167 ‘Section 306 Requirements for Group F Occupancies, Section 102 Definitions =... 1-67 Section 307 Requirements for Grouip H Occupancies 1-19 Section 703. Fireressive Material and Systems «1-67 Section 308 Requirements for Group I Occupancies 1-24 Section 704 Protection of Structural Members 1-68 Scstion 309 Roguicment for Group M Oceupancies 1-26 Section 705 Projections . 169 Section 310 Reguizements for Group R Occopancies 1-26 Section 706. Fire-esstve Joint Systems 1-09 Scetion 311 Requirements for Group $ Octupancies 1-28 Section 707 Insulation .».« 189 Section 312 Requirements for Group U Occupancies 1-31 Section 708. Fire Blocks and Dra Stops... 1-69 Section 709 Walls and Partitions .......eseveese 1470 Chapter 4 Special Use and Occupancy .....c.e6s0. IMT Section 710 Floor Ceilings or Roof Ceilings Ln Section 401 Scope coe ith Section 711 Shaft Enclosures ...++.+ssseeeveesn I-72 Scotion 402 Attit .s..se+s+ Mi Scction 712. Usable Space ender lors osscsss KB Section 403 Special Provisions for Group R Ortce Section 713 Fire-esisve Assemblies for Buildings and Group R, Division 1 Protection of Openings co AB ceupancies «.- ve ie Section 714 ‘Through-penetration Fre Stops «+... 7S Section 404 Covered Mall Buildings 13 Section 405 Stages and Platforms SO gg Chapter 8 Interior Finishes ...0..0cccecseeceere ESL Section 406 Motion Picture Projection Rooms ..., I-47 fae = poieaipicepionnainenininin is Section 802 Testing and Classification of Materials 1-91 fesse Ava et Arieostead goa dit See lag Section 803 Application of Controlled Interioe Finish 1-91 seid top ial ya i Section 80 Maximum Allowable Flame Spread... 1-91 Secon 10 Modis Gas Sytem in Grape B and oe ee tes ocupaneies Lag Section 806 Insultion sss seecsesseseeseeee 92 Section 411 Compressed Gases «..<.s+6s44 149 ee an ean 192, Section 412 Aviation Control Towers 1-49 Chaptor9 Fire-protection Systems <...2..cccsecs6 1-93 Section 413 Detention and Correction Facilites... 1-29 Section 901 Scope... : 1-93 Section $14 Agricultural Buildings . 48 Section 902 Standards of Quality 1.93 Section 415 Group R, Division 3 Occupancies, 9 Section 903 Definitions 1.93 Section 416 Group R, Division 4 Occupuncies .... 1-49 Section 904 Fire-entnguishing Systems... 1-94 Section 417 Barriers for Swimming Pools 149 Section 905 Smoke ComtOl -s.ssesceeceeeseess 196 Section 418 Fallout Shelters . veces MD Section 906 Smoke and Heat Venting 1-102 2ait‘TABLE OF CONTENTS—VOLUME 1 Chapter 10 Means of Egress. ‘Section 1001 Administrative Section 1002 Definitions ‘Section 1003. General : ‘Soction 1004 The Exit AccOsS ++ Section 1005 The Exit. ‘Section 1006 The Exit Discharge ‘Section 1007 Means of Egress Requirements Based (00 OCCUPABEY seve eee eneoe Reviewing Stands, Granstands, Bleachers, and Folding and ‘Telescoping Seating... Seotion 1009 Building Security Section 1008 Chapter 11, Accessibility Section HII Scope ...e+s+seeeees Seotion 1102 Definitions, . Section 1103 Building Accessibilty .. Section 1104 Egress and Atous of Refuge Seetion 1105 Facility Accessibility Section 1106 ‘Type B Dwelling Units Chapter 12 Interior Environment ‘Section 1201 General Section 1202. Light and Vetltion in Groaps A, B,E,F.H,1, Mand $ Occupancies Seetion 1203. Light and Ventilation in Group R Oveupancies Seetion 1204 Faves Seetion 1205 Alternate Ventilation when Applicable Chapter 13 Energy Conservation Seotion 1301. Solar Energy Collectors ‘Chapter 14 Exterior Wal Coverings... ase Seetion 1401 General Seotion 1402. Weather Protection ..... Seotion 1403. Veneer a Section 1404 Vinjl Siding. Chapter 15 Roofing and Roof Structores Section 1501 Scope Seetion 1502 Definitions Setion 1503 Rooting Req ‘Section 1504 Rooting Classification Scetion 1505 Aton: Accsss, Draft Stops ‘and Ventilation Scetion 1506 Roof Drainage - Section 1307 Rool-covering Materials and Application Section 1508 Valley Fleshing Section 1509 Other Flashing ‘Seation 1510. Roof Iosulation Section 1511 Penthouses and Roof Structures Section 1512 Towers and Spices Section 1513 Access to Rooftop Equipment ‘Excerpts from Chapter 16 ‘Structural Design Requirements 2 1-105 110s - 1-105 1-105 .i 1415 us 1419 a7 1147 L143, 14148 14g, 114s 1448 Ecerpis rom Chapter 17 ‘Structoral Tests and Tospections 1-165 Excerpts om Chapter 18 Toondations and Retaining Walls 1.169 fe cnmeres cera ieee eee acory Excerps from Chapter 21 Masonry Exerisfrom Chapt 22 oa Excerpisfom Chapter 2 ood " ans Chapter 24 Glass and Glaring 1.287 Sec 2401 Scopes. 1287 Scion 2402, Meatiestion- Last Section 2405 Are Liitations 1251 Section 404 Gling Spor snd Freming 1257 Section 405 Louvered Windows and Jnlases ©. 1-257 Section 2406 Safety Osxing : 157 Section 407 Hinged Shower Doors. eco. voces, 16258 Section 2408 Reequetbal and Squish Couns... 1-258 Seaton 2408. Sloped Glazing and Skylights 1359 Chapter 25 Gypsum Board aid Plaster 1261 Sesion 2501 Scope 1261 Section 2502 Materials LIIII a-aet Seton 2503 Vert Assembles... 1-262 Secon 2504 Horizontal Anenlies a8 Section 2505 Initioe Lab... 1382 Exterior ath | 1382 Section 2507 Ineo Paster 18 Secor 2508. Exterior Plaster 12683 Sein 2509 Eaposed Aggregte Paster 1-64 Section 2510 Poeomatcally Pised Pater (Gunite). 1-264 Sevion 2511 Gypsum Wallboard 1264 ‘Scetion 2512 Use of Gypsum in Showers and ‘Water Closets 1-265 Section 2513. Shearresiting Constructicn with ‘Wood Frame 1-265 (Chapter 26 Plast beeceesees E28 ‘Section 2601 SCOPE... ceseeee 1373 Scction 2602 Foam Plastic Insulation ...s...4+4.4 1-273 Section 2603. Light-ransmiting Plastics am Section 2604 Plastic Veneer FI 1-276 Chapter 27 Electrical Systems 1-279 ‘Section 2701, Bleetrial Code 1.279 ‘Chapter 28 Mechanical Systems . 1-281 ‘Section 280} Mechanical Code 1-281 Section 2802 Refrigeration System Machinery Room | 1-281 ‘Chapter 29 Plumbing Systems ... 1-283 Section 2901 Plumbing Code 1-283 Section 2902 Number of Fixtures 1-283 Scetion 2903. Alternate Number of Fiatures 2 1-283 Section 2904 Access to Water Closet Stool 1Chapter 30 Elevators, Dumbwaiters, Escalators and Moving Walks. 1-285 Scope Heda tte td O88, ‘Blevatos and Elevator Lobby Enclosures, 1-285 ‘Special Provisions ......- 1-285 Hojstwey Venting 1.287 levator Machine Room... 4. 1-287 Section 3006 Change in Use abit 1-287 Section 3007 Aditionel Doors 1-287 Chapter 31 Special Construction . 1-289 Section 3101 Scope. 1-289 Section 3102. Chimneys, Hieplaces and Barbecues... 1-289 Section 3103 ‘Temporary Buildings or Structures... 1-291 Chapter 32. Construction in the Public Right of Way ‘Section 3201 General 1-295 Section 3202 Projection into Alleys. ‘Section 3203. Space below Sidewalk ‘Section 3204 Balconies, Sun-control Devices and Appendages Section 3205. Marquees Section 3206 Awnings Section 3207 Doors Chapter 33 Site Work, Demolition and Construction 2. ‘Section 3301 Excavations and Fills 1.297 ‘Section 3302 Preparation of Building Site 1297 ‘Section 3303 Protetion of Pedestrians during Construction or Demolition . 1297 Chapter 34 Existing Structures . 1299 Section 401 General teens 1-299 Seetion 3402 Maintenance 1-299 Section 3403. Additions, Alterations or Repairs 1-299 Section 3404 Moved Buildings... = 1299 Section 3405 Change in Use 1299 Chapter 35. Uniform Building Code Standards ........ 1-30 Section 3501 UBC Standards 1301 Section 3502 Adopted Standaids cevereee 301 Sestion 3503 Standard of Duty ....e.-4-0-sese2++ 1-301 Section 3504 Recognized Standards... 1301 ‘Appendix Chapter'3. Use or Occupancy cee 809 Division Detention and Correctional Facilities... 1-309 Section 13 Scope. + 1309 Section 314 Application 1-309 Section 315 Definitions 1-309 Section 316 Construction, Requirement Exceptions . 1-309 Section 17 Compastmeatation . 1-309 Section 318 Occupancy Separations 1-309 Seation 319 Glazing 1-209 Section 320 Electrical 1309 Section 321 Automelie Sprinkler and Standpipe Systems 1-309 Section 322 Fire Alarm Systems - 1310 Section 323 Smoke Managentent 1-310 Section 324 Means of Fyress 1-310 Fenced Enclosures 1-210 ‘TABLE OF CONTENTS—VOLUME 1 Division Agricultura! Boildings az Section 326 Senpe 1312 Section 327 Constreti, Height and Allowable Areas. a2 Section 328 Occupancy Separations 1312 Section 329 Extetios Walls ead Openings ......... 1-312 Section 330 Means of Egress. te OZ Division IIL Requirements for Group B, Division 3 Occupancies 113 Section 331 General 133 Section 382 One and Two Family Dwelling Code Adopied 1313 Division TV Reguirements For Groap R, Division & Oecupancies Section 383 General Seetion 334 Construction, Height and Allowable Aten Scotion 335 Location on Property... +. Seetion 336 Noms oft eal Emerstey - taid Section 337 Laid Section 338. isd Section 339 Room Dimensions Lia Section 340 Shaft Enclosures - 1-315 Section 341. Fire Alarm Systems .. 1315 Section 342 Heating + 1315 Section 343 Special Huzards 1-315 Appendix Chapter 4 Special Use and Occupaney 1317 Division 1 Barriers for Simming Pools, Spas and Hat Tubs Section 419 General Section 420. Definitions... i Section 421 Requirements... Division Mt Aviation Contrul ‘Towers . Section 422 General . Section 423 Construction, Height and ‘Allowable Atex Means of Egress Section 424. Section 425 Fire Alerms Section 4265 Accessibility 427 Standby Power and Emeigency Generation Systems, Appendix Chapter 9 Basement Pipe Lalets . Section 907 Basement Pipe Inles Appendix Chapter 10 Building Security Seation 1010. Building Security Appendix Chapter 11 Accessibility... ionI Site Accessibility ‘Section 1107 Accessible Exte Scotion L108. Parking Faciives Section 1109. Passenger Loading Zones Divison I Accesbity for Exiting Buildings Section 1110, Scope. Seetion 1111 Definitions Seotion 1112. Alterations .......- Section 1113 Change of Occupancy Seetion 1114 Historie Preservation Routes « ‘Appendix Chapter 12 Interior Environment Division | Ventilation Section 1206 Scope ..-‘TABLE OF CONTENTS—VOLUME 1 Section 1207, Ventilation Division It Sound Transmission Control ‘Section 1208 Sound Transmission Control ‘Section 1209 Sound Transmission Contol Systems Appendix Chapter 13 Energy Conservation, New Building Construction +... Section 1302 Genesal Appendix Chapter 18 Reroofing ‘Section 1514. Genecel Beet Section 1S15 Inspection and Written Approval Section 1516 Reroofing Overlays Allowed Section 1517 Tile Ee Section 1518 Metal Roof Cavering Section 1519 Other Roofing -..-.. - Seetion 1520 Flashing and Raging 5 Excerpts from Appendix Chapter 16 ‘Structural Forces Excerpts from Appendtx Chapter 18 ‘Waterproofing and Dampproofing Foundations ‘Excerpts from Appendix Chapter 19 Protection of Residential Concrete Exposed {o Freezing and Thawing Excerpts fom Appendix Chapter 21 resenplive Macenty Consiraction tn ighind Areas : Excerpts from Appendix Chapter 23 ‘onventional Light-feame Construction in Highwind Areas Appendix Chapter 29 Minimum Plumbing Fixtures Section 2008 Genera Appendix Chapter 30 Elevators, Dt [Escalators and Moving, Walks Seation 3008 Purpose Section 3009 Scope Section 3010 Definitions : : Seetion 3011 Permits—Certifieates of Inspection Seetion 3012 ANSI Cade Adopted : Section 3013 Design Scetion 3014 Requirements for Operation and Maintenance Unsute Conditions Section 3015 Appendix Chapter 31 Special Construction Division | Flood-resistant Construction Section 3104 General ‘Section 3195 Manufactured Struccures Section 3105. Protection of Mechanical and Electrical Systoms Flood Hazard Zones—A Zones ‘Coastal High Hazard Zoues— Vdones . Seetion 3109 Elevation Cectiication Seetion 3119 Design Requirements Division TT Membrane Structures Section MLL General ‘Section 3107 Section 3108 ax 13s 137 1-391 4-397 1307 - 1399 1399 1-399 1399 1399 1399 1-399 09 1-400) 1401 1401 1401 1401 1401 1401 401 1402 L402 1403 1403, Section 3112 ‘Type of Construction and General Requirements Seotion 3113. Inflation Systems ‘Section 3114 Scotion Provisions Section 3115. Engineering Design on HI Patio Covers ‘Section 3116 Patio Covers Defined ‘Section 3117 Design Loads Section 3118 Light and Ventilation ‘Scction 3119 Footings Appendix Chapter 33 Exeavation and Grading Seotion 3304 Purpose Scotion 3305 Scope Seotion 3306 Permits Required . Seotion 3307 Hazards Section 3308 Definitions : Section 3309 Grading Permit Requirements Scotion 3310 Grading Fees . Section 3311 Bonds Seotion 3312 Cuts I Scotion 3313 Fills... Seotion 3314. Setbacks Seotion 3315 Section 3316 Section 3317 Scetion 3318 Completion of Work. Drainage and Terracing Erosion C¢ trol. Appendix Chapter 34 Existing Structures ...... Division Life-safety Requirements for Existing. Buildings Other than High-tise Buildings Section 3406 Seotion 3407 Seetion 3408 Section 3409) General Exits ‘Enclosure of Vetical Shafts ‘Basement Access or Sprinkler Protection i Staadpipes Smoke Detectors Separation of Oecupancies safety Requirements for dng High-rise Buildings Scope. General Complisnce Data . ee Authority of the Building Officiat ‘Section 3417 Appeals Board Section 3418 Specific Provisions and Alternates Division TIT Repairs 9 Buildings and Structures Damaged by the Occurrence of a Natural Disaster Section 3419 Purpose -..-..seyeveseee ‘Section 3420 General Section 3421, Structural Repaits Section 3422 Nonstmmctnral Repairs to Light Fintures and Suspended Ceilings Seotion 3410 Scotion 3411 Section 3412 ion Li Bi Seotion 3413 Seotion 3414 Scotion 3415 Section 3416 UNIT CONVERSION TABLES. INDEX 1403 1403‘TABLE OF CONTENTS—VOLUME 2 Nel ‘Table of Contents—Volume 2 Structural Engineering Design Provisions Te Effective Use of the Uniform Building Code (Chapter 16 Structural Design Requirements . Dba EL Sebi ee nce nee Seation 1601 Senge o Section 1602 Definitions Section 1608 Notations ... i Section 1604 Standards... -.-.- 7 Scction 1605. Design 7 Section 1606 Dead Lows ....-.-. 7 Section 1607 Live Loads Section 1608 Snow Loads Section 1609 Wind Loads Section 1610 Earthquake Loads Section 1611 Other Minimum Loads Section 1612 Combinations of Loads Section 1613 Deflection Division I Snow Loads ...- Section 1614 Snow Loads - I Wind Design ... Section 1615 General Section 1616 Definitions Section 1617 Symbols and Novations Section 1618 Basic Wind Speed Section 1619 Expose ...-..ssesssesess Section 1620 Design Wind Pressures... Section 1621, Primary Frames and Systems Section 1622 Elomonts and Components of Sirctures Scetion 1623 Open-frame Towers Section 1624 Miscellaneous Structures Section 1625 Occupancy Categories «2... Division IV Earthquake Design : Divi Section 1626 General Section 1627 Definitions... ++ Seetion 1628 Symbols and Notations Section 1629 Criteria Selection ‘Minimum Design Lateral Forces and Related Effects 7 Dynamic Analysis Procedures... Lateral Force on lements of Structures, Nonstructural Components ul Equipment Supported by Stuctaces Detailed Systoms Design Requirements Nonbuilding Structures . Earthquake-recording, Division V__ Soil Profile Types Seetion 1636. Site Categorization Procedure . Section 1630 sirumentations ‘Chapter 17 Structural Tests and Inspections Section 1701 Special lospections i Seetion 1702. Structural Observation Section 1703. Nondestructive Testing Section 1704 Prefsbricated Construction Daxwiti az 2a mt 2 2 2a 2 22 22 23 23 23 2 a 28 26 26 24 2 27 2 28 28 219 2a 22 2a 233 239 239 2-40 241 241 Chaper1 Foundatons an ting Wal 243 sion General 23 ‘Section 1801 Scop 28 Section 1802. Quality and Design 243 Section 1803. Soil Clasificstion—Expansive Soil... 2-45, Section 1804 Foundation Investigation . a3 Section 1805 Allowable Foundation and Lateral Pressures 2a Section L806 Footings 244 Section 1867 Piles—General Requirements 245 Section 1808 Specific Pte Requirements 245 Section 1809 Foundation Constructon— Seismic Zones Sand 4vesceecsssese 288 Division IT Design Standard for Treated Wood Poatsdalon ystere Section 1810 Scope Section 1811 Materials Section 1812. Drainage and Moisture Contol Section 1813 Design Loads ection 1814. Siuctral Design MIL Design Standard for Des Slab-on-groand Foundations to Resa the Elects of Expansive Soils und Compressible Sails sou 254 Section 1815 Design of Slab-on-Ground Foundations [Based on Design of Slab-on-Ground Foundations ofthe Wire Reinforcement Insite, Ines (Aug, 1982)] Section 1816. Design of Postensioned Slabs oa Grourd (Based on Design Specification ofthe Postensioning instvte) sy s.s-se- 2085 Section 1817 Appendix (A Procedure for Estimation ‘ofthe Amount of Climate Controlied Differential Movement of Expansive Soils) Section 1818 Appendia 3 (Simplified Procedures foe ‘Determining Cation Exchange Capacity and Cation Exchange Activity) 260 Section 1819 Design of Postinsioned Sls on Compressible Soils (Based on Design ‘Specifications ofthe Pstensioning Insttte) --. vitteces 2661 Chapter 19 Conerete 297 Division! General 297 ‘Section 1900 General 297 Divioo Hw... seesasceeeee 298 ‘Section 1901 Scope an 298 Section 1902 Definitions 298 Section 1903. Specitications for Tests and Materials «2-99 Section 190% Durability Requirements. 2101 Section 1905 Concrete Quay, Mixing snd Placing -. 2-102 ‘Satin 1906. Formwork, Embedded Pipes and ‘Coastrution Joins Section 1997 Details of Reinforcement Section 1908 Analysis and Design Secon 1909 Seng and Sevciiy Requirenseats‘TABLE OF CONTENTS—VOLUME 2 Section 1910 Floxure and Axial Loads «6. 5..6.6+5 Section 1911 Shear and Toxsion Section 1912 Development and Splices of Reinforeement Seetion 1913 Two-way Sleb Section 1914 Walls... Section 1915 Footings ‘Section 1916 Precast Conerste Section 1917 Composite Conccte Femara Members ‘Section 1918 Prestressed Concrete Scction 1919 Shells and Folded Plates. Scction 1920 Strength Evaluation of Existing Structures Reinforced Concrete Str Resisting Forces Induced by Earthquake Motions Section 1922 Structural Plain Concrete Division IIT Design Standard for Anchorage to Concrete Section 1923 Anchorage to Concrete Division IV Design and Construction Standard Section 1921 for Shoterete Section 1924 Shoterete Division V Design Standard for Reintorced | Gypsum Conerete Section 1925 Reinforced Gypsum Conercte Division VE_ Alternate Design Method Section 1926 Altemate Design Method Division VI_ Unified Design Provisions ..-........ ‘Section 1927 Unified Design Provisions for Reinforced and Prestressed Concrete Flexural and Compression Members Division VIII Alternative Load-factor Combination and Strength Reduction Factors... .-.- Section 1928 Alternative Load-factor Combination ‘and Strength Reduction Factors... Chapter 20 Lightweight Metals Division General Section 2001. Material Siandards and Symbols - Section 2002 Allowable Strsses for Members ‘and Fasteners Seotion 2003. Design : Section 2M Fabrication and Brection vision Design Standard for Aluminam Structures Section 2005 Scope Scotion 2006 Materials Section 2007 Design Section 2008 Allowable Stresses Section 2009 Special Design Rules Section 2010 Mechanical Connections Section 2011 Fabrication... ree Section 2012 Welded Construction +... 1. Section 2013 Tesiag. cs esecsceeee Chapter 21. Masonry ‘Scetion 2101 General ‘Spetion 2102. Material Standards Sootion 2103 Mortar and Grout... Section 2104 Construction exit 2s vy 21d 2431 2136 244l 2182 par 2445 2447 2451 2153 21584 2165 2168 2168 2410 2170 2am 24171 aan 2a 2176 2176 2178 2178 2185 2185 Diss 286 2.487 2487 2-192 2192 2192 2192 2192 2192 2495 2.195, 2197 2198, 2-203 2203 2-205 2-206 2207 Section 2105. Quality Assurance Sarit meats o 2210 Sesion 2106 Oo Dei Rs Section 2107 ress Design of Masomry .... 2-214 Section 2108 2219 Section 2109 2-205 Section 2110 Glass Masonry 22a Section 2111 Chiemneys, Fireplaces and Barbecues ... 2-228 Chapter 22. Steel Division | General........ Section 2201 Scope .. 7 2237 Section 2202 Siandars of Quilty «2... 22037 Section 2203 Material Kdeniiication 2237 Section 2204 Design Methods... o. 2-237 Section 2205 Design and Constuctiom Provisions ... 2-237 Division IT Design Standard for Load and Resistance actor Design Speciation for Stractoral Steel Buildings -.-- 2230 Section 2205 Adoption : 22 Scetinn 2207 Amendments 2239) Division HI Design Standard for Specification for Structural Steel Buildings Allowable Stress Desiga and Plastic Design 2240 Section 2208 Adoption 2240 Section 2209 Amendments ....... 20 Division 1V Sami Provisions for Srctrat ‘Steel Buildings 2201 Section 2210 Amendments 2-241 Section 2211 Adoption 2243 Division V Seismic Provisions for Structural ‘Steel Buildings for Use with Allowable Stress Design 7 2-255 Section 2212 General — ces 22055 ‘Section 2213. Seismie Provisions for Structural Sieel Bukdings im Seismic Zones 3 nd 4... 2-255 Section 2214 Seismic Provisions for Structural Steel Buildings in Seismic Zones 1 nd 2... 2-261 VI Load and Resistance Factor Design ‘Specification for Cold-formed Stee! Structural Members Section 2215 Adoption Section 2216 Amendments Division VIT_ Specification for Design of Steet Structural Members Section 2217 Adoption . Seotion 2218 Amendments Division VIII Loteral Resistance for Stee! Stud Wall Systems Seotion 2219 General... : Section 2220- Special Requirements in Seismic Zones 3and4 .... 2-266 jon TX Open Web Steet Joists Section 2221 Adoption 2 Division X Design Standard for Steel Storage Racks Section 2222 General Provisions i i Section 2223 Design Procedures and Dimensional Limitations ‘Scorn 2224 Allowable Stresses and Ffective ths Section 2225 Pallet and Stacker-rack Beams Section 2226 Frame Design ... ‘Section 2227 Connections and Bearing Plates Divisi DiSection 2228 Loads 220 Section 2229 Special Rack Desiga Provisions nan jon XI Design Standard for Structural Applications of Steel Cables for Balldings sees 22M Section 2230 Adoption 2212 Chapter 23 Wood .......--2-ssteeeeseees cesses 2208 Division I General Ds Rgueeents 7 228 ‘Section 2301 General .-...- . 227 ection 2302. Definitions... Section 2303. Standards of Quality Section 2304 Minimum Quality . ‘Section 2305. Design and Construction Requirements. Division IT General Requirements... ‘Section 2306 Decay and Termite Protection ‘ ‘Section 2307 Wood Supporting Masomry or Concrete Seetioa 2308 Wall Framing, ‘Soction 2309 Floor Fr Section 2310 Exterior Wall Coverings Seotion 2311 Interior Pancling Section 2312. Sheathing Scction 2313. Mechanically Laminated Floors and Decks ‘Section 2314 Post-Beam Connections as ‘Section 2315 Wood Shear Walls and Diaphragms Division IIL Design Specifications for Allowable ‘Stress Design of Wood Buildings Section 2316 Design Specifications ; Section 2317. Plywood Structural Panels +4... Section 2318 Timber Connectors and Festeners Section 2319 Wood Shear Walls and Diaphragms Division IV Conventional Light-frame Construction Section 232 Coaventional light-frame Construction Design Frovisions . 2-299 Division V__ Design Standard for Metal Plate Connected Wood Truss «0.0 4...e650265 2-339 ‘Section 2321 Metal Plate Connected Wood Truss Design 2-339 Divison VI Design Standard for Structural Gined Buil-ap Members—Piywood Components . 2-340 Section 2322, Plywood Stressed Skin Pancls 2340) Scotion 2323. Plywood Curved Panels 2-340 Seotion 2324 Plywood Beams... 2-342 Section 2325. Plywood Sandwich Panels 2344 Section 2326 Fabrication of Plywood Components, 2-345 Seetion 2327 All-plywood Beams... 2349 Division VII Design Standard for Span Tables for Joists and Raters. 2-357 Seetion 2328 Span Tables fr Joists and Rafers 2357 Section 2329 Design Criteria for Joists and Rafters ... 2-387 Sestion 2330 Lumber Stesses ..+.eee e+ 2-397 Seetion 2331 Moisture Content 2.357 Section 2332 Lumber Size 7 Section 2333. Span Tables for Joists and Raters 2-387 Division VEIT Design Standard for lank-and-benm Framing =... 2374 Section 2334 Scope 2374 Scation 2335. Definition - 2374 ‘TABLE OF CONTENTS—VOLUME 2 Section 2336. Design coos eesses aa Excerpts from Chapter 24 ins and Glaring «+=... 29 Excerpts thom Chapter 25 Gypsum Hoard and Paster 2381 [Bxcerpts from Chapter 35. ‘Uniform Building Code Standards Section 3501 UBC Standards Section 3502 Adopted Standards Section 3503. Standard of Duty - Section 3504 Revognized Standards Appendix Chapter 16 Structural Forees Division — Snow Load Design ‘Section 1637 General . ‘Section 1638 Notations... ..+ Section 1639 Ground Snow Loads - Section 1640 Roof Snow Loads Section 1641. Unbalanced Snow Loads, Gable Roos . 2-388 Section 1642 Unbalanced Snow Load for Curved Roots 2-388) Section 1643 Special Rave Requirements 2-388 ‘Section 1644 Drift Loads on Lower Rools, Decks 1nd Roof Projections... 2.e.r 0145 2-388 Section 1645 Rain on Snow - 2-389 Section 1646 Deflections 2389 Section 1647 Impact Loads . 2389 ‘Section 1648. Vertical Obstructions . 2-389) Division It Earthquake Secordiglasrameuiton 2-400 Section 1649 General wees 2400 Section 1650 Location . 2400 Section 1651 Maintenance 2-400 Scetion 1652 Instrumentation of Existing Buildings .. 2-400 Division IIT Seismic Zone Tabulation .. 2401 ‘Section 1653 For Areas Outside the United States... 2-401 Division IV Earthquake Regulations for Selsmic-isolated Structures ,... 2.2.2... 2-405 Section 1654 Generat 2-405 Seetion 1655 Definitions. . 2405 Section 1656 Symbols and Notations...) e+e. 2-405 Section 1657 Criteria Selection cee 2407 Section 1658. Static Lateral Response Procedure ..... 2-407 Section 1659 Dynamic Laterl-Respoose Procedure .. 2-409 Section 1660 Lateral Load on Elements ‘of Structures and Nonstructural ‘Components Supported by Structures. 2-410 Section 1661 Detailed Systems Requizemcnis 24u1 Section 1662. Nonbuilding Structures 2412 Section 1663. Foundations cetteeeeseeeses 2612 Section 1664 Design and Construction Review 2412, ‘Section 1665 Required Tests of Isolation System .... 2-412 Appendix Chapter 18 Waterproofing and ‘Dampproofing Foundations 247 Section 1820 Scope a 2417 Section 1821 Groundwater Table Investigation .,.... 2-417 Section 1822 Dampproofing Required 2417 2417 2417 ex Section 1823 Floor Dampproving ‘Section 1824 Wall Dampproofing‘TABLE OF CONTENTS—VOLUNE 2 Other Dampproofing Requirements .,.. 2-417 Section 1826. Waterproofing Regured .... 2417 Section 1827, Floor Waterproofing 2 ats Section 1828. Wall Walerproofing -. 2-418 Section 1829 Other Dampprooting and Wacrreoing Requirements... 48 Appendix Chapter 19. Protection of Residential “Concrete Exposed to Freeaing and Thawing 2419 Section 1928. Gonerdl ss. ssesseesserseesseree 2419 ‘Appendix Chapter 21 Prescriptive Masonry ‘Construction in Highvwind Areas ws s7...2+.2-. 2-421 Section 212. General 2421 Appendix Chapter 23. Conventional Light-frame “Contraction in Highemind Aress 2465 Section 2337 General, Eira aes ~ UNIT CONVERSION TABLES ..2..¢0.cesseesce00 2471 INDEX cope pecceeieees ceceeeebeeteee AIS+1997 UNIFORM BUILDING CODE ‘oHaP. 16, ow. 160521 Volume 2 ‘Chapters 1 through 15 are printed in Volume 1 of the Uniform Building Code. Chapter 16 STRUCTURAL DESIGN REQUIREMENTS NOTE: This chapter has been revised In Its entirety. Division I-GENERAL DESIGN REQUIREMENTS SECTION 1601 — SCOPE ‘This chapter prescribes general design requirements applicable to all structures regulated by this code, ‘SECTION 1602 — DEFINITIONS ‘The following terms are defined for use in this code: ALLOWABLE STRESS DESIGN is 4 method of proportion- ing structural clemonts such that computed siresses produced in the elements by the allowable stress load combinations do not ‘exceed specified allowable stress (also called working, stress design) BALCONY, EXTERIOR, isan exterior floor system proj ing from a structure and supported by that structure, with no a tional independent supports DEAD LOADS consist of the weigt ofall materials and fixed equipment incorporated iato the building or other structore DECK is an exterior floor system supported on at Teast two opposing sides by an adjoining structure and/or posts, piers, or other independent supports. FACTORED LOAD is the product of a load specified in Sec- tious 1606 through 1611 and a load factor. See Section 16122 for ‘combinations of lactored loads. LIMIT STATE is 4 condition in whieh a structure or compo- nent is judged either to be no longer useful for is intended function (Gerviceabilty limit state) or to be unsafe (sitength limit state). LIVE LOADS are those loads produced by the use and oocu- pancy of the building or other structure and co not include dead Jou, construction load, or envizonmental Toads such as wind load, ‘snow load, rain Toad, earthquake load or flood lead. LOAD AND RESISTANCE FACTOR DESIGN (LRED) isa rmcthod of proportioning structural elements using load and resist- tance factors such that no applicable limit state is reached when the structure is subjected to all appropriate load combinations. The term “LRFD” is used in the design of steel and wood structures. STRENGTH DESIGN is a method of proportioning structural elements such that the computed forces produced in the elements by the factored load combinations do nol exceed the factored ele rent strength. The term “strength design” is used inthe design of concrete and masonry structures, ‘SECTION 1603 — NOTATIONS D = dead load. E. = earthquake load set forth in Section 1630.1. Fm = estimated maximum earthquake force that can be devel- ‘oped in the structure as set forth in Section 1630.1.1, load due to fluids load due to lateral pressure of soil und water in soil. L ive load, except roof live lond, including any permitted live load reduction. roof live load, including any permitted live load reduction ponding load. snow lod. selfstraining force and effects arising from contraction. or expansion resulting from temperature change, shrink age, moisture change, creep in component materials, movement due 0 differential settlement, or combina tions thereof, W. = load due to wind pressure. saw & SECTION 1604— STANDARDS. sd below are recognized standards (see Section 1. Wind Desiga. 1.1 ASCE 7, Chapter 6, Minimum Design Loads for Buildings and Other Structures 1.2. ANSIFIA/TIA 222-8, Structural Standards for Stee] ‘Antenna Towers and Antenna Supporting Structures 1.3. ANSVNAAMM FP1001, Guide Specilications for the Design Loads of Metal Flagpoles SECTION 1605 — DESIGN 1605.1 General. Buildings and other structares and all portions thereof shall be designed and constracicd to sustsin, within the imitations specified inthis code, ll loads set forth in Chapter 16 and elsewhere in this code, combined in accordance with Section 1612, Design shall he in accordance with Strength Desiga, Load and Resistance Factor Design or Allowable Stress Design meth- ‘ods, as permitted by the applicable matcrials chapters. EXCEPTION: Uless aterwiserequited by the building effet fe cenventnnal igh izning raquloesnt poled ia Chapter 23 of this code shall he deemed wo met tho requirements of this seco, 1605.2 Rationality. Any system or method of eonsiru used sliall be based on a rational analysis in uocondance: established principles of mechanics. Such analysis shall result in a sysiem that provides:2 complete load path capable of transferring ads and forees from their point of origin to the load-resisting Clements, The analysis shall include, but not be limited to, the pro- visions of Sections 1605.21 through 1605.23. 1608.2.1 Distribution of horizontal shear. The total lateral force shall be distributed to the various vertical elements of the Iteral-force-resisting system in proportion to their rigidities con- sidering the rigidity of the horizontal bracing system or dia- phragm, Rigid elements that are assumed not to be part of the lateral-force-resisting system may be incorporated into buildings, provided that thei effect on the action of the system is considered and provided for in the design. 24CHAP. 16, DVI $605.2. 160742 Provision shall be made for the increased forces induced on resisting elements of the structural system resulting from torsion ‘due (o eccentricity between the ceater of application of the lateral forces and the center of rigidity ofthe lateral-force-resisting sys- tem, For accidental torsion requirements for seisinie design, see Section 1630.6, 1608.2.2 Stubility against overturning, Every structure shall be designed to resist the overturning effects caused by the lateral forces specified inthis chapter. See Section 1611.6 for retaining walls, Section 1615 for wind and Section 1626 for seismic, 1605.23 Anchorage. Anchorage of the roof lo walls and col- ‘umns, snl of walls and columns to foundations, shall be provided to resist the uplift and sliding forces that result from the applics- tion of the preseribed forces. Concrete and masonry walls shall be anchored {o all floors, soos and other stractoral elements that provide lateral support for ‘the wall. Such anchorage shall provide a positive direct connce~ tion capable of resisting the horizontal forces specified in this chapter but not less than the miaimum forces in Section 1611.4. fn addition, ia Seismic Zones 3 and 4, diaphragm to wall anchorage sing embedded straps shall have the sireps attached to or hooked around the reinforcing steel or athcrwise terminated 50 as to effcc~ tively transfer forces to the reinforcing steel. Walls shall he designed to resist bending between anchors where the anchor spacing exceeds 4 feet (1219 mm). Required anchors in masonry ‘walls of hollow units or cavity walis shall be embedded in a rein~ forced grouted structural element ofthe wall. See Sections 1632, 1633.28 and 1633.2.9 for earthquake design requirements. 1605.3 Ereetion of Structural Framing. Walls and structural framing shall be erected true and plumb in accordance with the design. SECTION 1606 — DEAD LOADS 1606.1 General. Dead loads shall be as defined in Section 1602 nd this section, 1606.2 Partition Loads. Floors in office buildings and other buildings where partition locations are subject to change shall be designed to suppost, in addition to all olber loads, a uniformly dis tributed dead load equal to 20 pounds per square foot (psf) (0.96 Nim?) of floor ave EXCEPTION: Access floor syteas shill be designed suppor. in adi ol be aes, a vnormlydistbuted dead load not less than 10 pat (048 KNin!) of lor area, SECTION 1607 — LIVE LOADS 1607.1 General. Live Jouds shall be the maximum Toads expected by the intended use er cocupancy but in no case shall he Tess than the loads required by this section. 1607.2. Critical Distribution of Live Loads. Where structural members are arranged to create continuity, members shall be designed using the loading conditions, wihich would cause maxi- ‘mum shear and bending moments. This requirement may be sat fied ia accordance with the provisions of Section 1607.3.2 or 1607.4.2, where applicable. 1607.3 Floor Live Loads. 16073.1 General. Floors shall be designed for the unit live loads as sot forth in Table 16-A. These Loads shall be taken as the ‘minizaum live loads in pounds per square foot of horizontal pro- jection to be used in the design of buildings for the occupancies 22 1997 UNIFORM BUILDING CODE listed, and loads at Teast equal shall be assumed for uses not listed inthis section but that create or accommodate similar loadings. ‘Where it can be determined in designing floors tat the actual live load will be greater than the value shown in Table 16-A, the actual live laud shall be used inthe design of such buildings or por- tions thereof. Special provisions shall be mude for machine and apparatus loads. 1607.3.2 Distribution of uniform floor loads. Where uniform floor loads are involved, consideration may be limited to full dead load on all spans in combination with full live load oa adjacent spans and alternate spans. 160733 Concentrated loads. Provision shall be made in designing floors fora concentrated Toud, L, asset forth in Table 16-A placed upon any space 22 feet (762 mm) square, wherever thie load upon so otherise usloaded floor would produce stresses greater than those eaused by the uniform load requied therefor. Provision shall be made in arcas where vehicles are nsed ot stored For concentrated loads, , consisting of two or more loads spaced § feet (1524 mm) nominally on center without uniform live Tocds, Bach load shall bo 40 percent of the gross weight of the ‘maximum-size vehicle to be accommodated. Parking garages for the storage of private or pleasure-ype moior vehicies with no repair a refueling shall hve a for system designed for a coacen- tiated Yo of not less than 2,000 pounds (8.9 KN) acting onan area ‘of 2h square inches (12.903 mum?) without uniform ive loads. The condition of concentrated of uniform live Toad, combined in accordance with Section 1612.2 or 16123 as appropriate, produc- ing the greatest stresses shall govera. 1607.3.4 Special loads. Provision shall be made for the special vertical and lateral loads as set forth in Table 16-B. 1607.3. Live loads posted. ‘The live londs for which each floor fr portion thereof of 2 commercial or industrial building is or fis teen designed shall heve such design live loads conspicuously posted by the owncr in that part of each story in which they apply, ‘using durable metal signs, and it shall he unlawful to remove or deface such notices. The eccupant of the building shall be respon- sible for keeping the actual load below the allowable limits. 1607.4 Roof Live Loads. 1607.41 General. Roofs shall be designed for the unit live loads, Z,, set fort in Table 16-C. The live loads shall be assumed to act vertically upon the area projected on 2 horizontal plane. 1607.4.2 Distribution of loads. Where uniform roof loads are involved in the design of structural members arranged to create continuity, consideration may be limited to full dead loads on all spans in combination with full roof live loads on adjacent spans and on alternate spans. EXCEPTION: Altnate span loading need aot be considered sshere the vaiform re live lod is 20 pet (06 LNs) or more or ‘whore load combinations, nclading sow ld, esl larger mens ber a cannectons For those conditions where light-gege metal preformed struc tural sheels serve as the support and finish of roofs, rot structural ‘members arranged to create continuity shall be considered adc- ‘quate if designed for full dead loads on sll spans in combination ‘With the most critics! one ofthe following superimposed londs: 4. Snow load in accordance with Section 1614. 2, The uniform root live load, L,, set forth in Table 16-C on all, spans. 3. A concentrated gravity load, L,, of 2.000 pounds (8.9 kN) placed on any span supporling a tributary area greater than 200 square feet (18.58 m2) lo creale maximum stresses in the member,1997 UNIFORM BUILDING CODE whenever this loading creates greater stresses than those caused by the uniform live load. The concentrated load shall be placed on tthe member over a length of 2/2 feet (762 mm) along the span. The concentrated load need nol be applied to more then one sp ‘simultaneously. 4. Water accumulation as prescribed in Section 1611.7. 1607.4.3. Unbalanced loading, Unbalanced loads shall be used ‘where such loading will esult in larger members or connections. ‘Trusses and arches shall be designed to resist the stresses caused by unit live Toads on one half of the span if such loading results in reverse stresses, or stresses grater in any portion than the stresses produced by the required unit live loed on the entite span. For Toofs whose structures axe composed ofa stressed shell, framed or solid, wherein stresses caused by any point loading ae distributed ‘throughout the area of the shell, the requirements for unbalanced unit live load design may be reduced 50 percent 1607.44 Special roof loads, Roofs to be used for special pur- poses shall be designed for appropriate loads as approved by the building official. Greenhouse roof bars, purlins and rafters shall be designed (0 ccarty a 100-pound-minimum (444.8 N) concentrated load, Z, in addition to the uniform live load. 1607.5 Reduction of Live Loads. The design live load deter- ‘mined using the unit live loads as set forth in Table 16-A for floors and Table 16-C, Method 2, for roofs may be reduced on any mem= ber supporting mors than 150 square feet (13.94 m2), including flat slabs, except for floors in places of public assembly and for live loads greater than 100 psf (4.79 kN/m?), in accordance with the following formula: Rer(A~150) a) Por Siz Rear (A-13.94) ‘The reduction shall not execed 40 percent for members receiv- ing load from one level only, 60 porcent for other members or R, as dolermined by the following formala: R=21 (1+ DIL) @ WHERE: A. = area of floor or roof supported by the member, square feet (m?. D_ = dead load per square foot (m?) of arca supported by the member. L_ = unit live load per square foot (m2) of area supported by the member. reduction in percentage. zate of reduction equal to 0.08 percent for floors. See Table 16-C for roofs For storage loads exceeding 100 psf (4.79 kN/i?), no reduction shall be made, except that design live loads on columns may be reduced 20 percent ‘The live Toad reduction shall not exceed 40 percent in garages for the storage of private pleasure cars having a capacity of not more than nine passengers per vehicle, 1607.6 Alternate Floor Live Load Reduction. As an altemate to Formula (7-1), the unit live Toads set forth in Table 16-A may be reduced in accordance with Formula (7-3) on any member, includ ing flat slabs, having an influence area of 400 square feet (37.2 m2) For SI: 1 oi fen(g)] ‘Aj = ingluence area, i square fet (m2). The influence area Ay is four times the tributary area for a coturan, two times the tributary area fora beam, equal to the panel area for @ two-way slab, and equal tothe product ofthe span and the full ange width fora precast T-beam. L = reduced desiga live load per square foot (m2) of area supported by the member. 1L, = uareduced design live load per square foot (m?) of area supported by the member (Table 16-4). “The reduced live load shall not be less chan SO percent of the writ live load ly for members recsiving load from one level only, nor less than 40 pereent ofthe unit live load Z» for other members. SECTION 1608 — SNOW LOADS ‘Snow loads shall be determined in accordance with Chapter 16, Division Th ‘SECTION 1609— WIND LOADS ‘Wind loads shall be determined in accordance with Chapter 16, Division TI. ‘SECTION 1610 — EARTHQUAKE LOADS ‘Barthquake loads shall be determined in accordance with Chapter 16, Division IV. ‘SECTION 1611 — OTHER MINIMUM LOADS 16LLA General, In addition tothe other design loads specified in this chapter, structures shall be designed to resist the loads spe ified in this section and the special loads set forth in Table 16-B. 1611.2 Other Loads. Buildings and other structures and por- tions thereof shall be designed to resist all loads due to applicable fluid pressures, F lateral soil pressures, H, ponding loads, P. and solf-straining forces, T See Section 1611.1 for ponding loads for 00's, 1611.3 Impact Loads. Impact loads shall be included in the \desiga of any structure where impact loads occur. 16114 Anchorage of Concrete and Masonry Walls. Concrete ‘nd masonry walls shall be anchored as required by Section 1605.2.3. Such anchorage shall be capable of tesisting the load combinations of Section 16122 or 1612.3 using the greater of the ‘wind or earthquake loads required by this chapter or « minimum horizontal foree of 280) pounds per linea foot (4.09 kN/m) of wall, substituted for E 1GLLS Interior Wall Loads, Intrioe walls, permanent patitions and temporary paritions that exezed 6 fect (1829 mum) in height shall be designed to esis all load to which they ae subjected but not less than a load, L, of 5 pst (0.24 KN/n2) applied petpendica lar to the walls. The S psf (0.24 kNim?) load need not be applied slimuitaneously wih wind or seismic loads. The defection of sxc 28Har. 16, DIV. Tens 181232 ‘walls under a load of 5 psf (0.24 KN/in?) shall not execed "aap of the span for walls with brittle finishes and '/129 of the span for ‘walls with flexible finishes. See Table 16-O for earthquake design requirements where such requirements are more restrictive. EXCEPTION: Flesile, folding or porable partons are not rehired to meet the Toad ad delecion entra bu must be anchored to the supponting structre co mee the provisions of his ode 1611.6 Retaining Walls. Retaining walls shall be designed to resist loads duc to the lateral pressure of retained material in accordance with accepted engineering practice. Walls retaining drained soil, where the surface ofthe retained soi is level, shall be ‘designed for a load, H, equivalent to that exerted by a fluid weigh- ‘ng not less than 30 psf per foot of depth (4.71 kN/m2/m) and hav- ing a depth equal to that ofthe retained soil. Any surcharge shall be jm addition to the equivalent fluid pressure. Retaining walls shall be designed to resist sliding by at least 1.5 times the lateral force and overturning by atleast | 5 times the ‘overturning moment, using allowable stress design loads. 1611.7 Water Accumulation, All roofs shall be designed with sufficient slope or camber to ensure adequate drainage after the long-term deflection from dead load or shall be designed to resist ponding load, P. combined in accordance with Section 1612.2 or 1612.3. Ponding load shall include water accumulation from any source, including snow, due to deflection, See Section 1506 and ‘Table 16-C, Footnote 3, for drainage slope. Sce Section 1615 for deflection criteria, 16118 Hydrostatic Uplift. All foundations, slabs and other footings subjected to water pressure shall be designed to resist @ uniformly distributed uplift Toad, & equal to the full hydrostatic pressure. 1611.9 Flood-resistant Construction. For flood-tesistant con- struction requirements, where specifically adopted, see Appendix Chapter 31, Division I. 1611.10 Heliport and Helistop Landing Areas. In addition to other design requirements of this chapter, heliport and helistop landing or touchdown areas shall be designed for the following loads, combined in accordance with Section 1612.2 or 1612.3: 1, Dead load plus actual weight of the helicopter 2, Dead load pls asngle connate impat on, , cover ing 1 square foot (0.093 m) of 0.75 times te fully loaded weight of the helicopter if it 3s equipped with hydraulic-type shock absorbers, or [5 times the fly Toaded weight ofthe helicoper it itis equipped with a rigid orski-iype landing gear. 3. The deat load pls e uniform iv oad, £0100 pst (4.8 KN mm) The required ive load may be reduced in accordance with Section 1607.5 or 1607.6. 1611.11. Prefabricated Construction. 1611.11.41 Connections. Every device used to connect pre- {ubricated assemblies shall be designed as required by this code ‘and shall be capable of developing the strength of the members connected, except in the case of members forming part of astruc- tural frame designed us specified inthis chapter. Comnections shall bbe cupable of withstanding uplift forces as specified in this chapter. 1611.11.2 Pipes and conduit. In structural design, due allowance shall be made for any material to be removed for the installation of pipes, conduits or other equipment 1G1L.113 Tests and inspections. See Section 1764 for require- ments for tests and inspections of prefabricated construction. ry 1997 UNIFORM BUILDING CODE ‘SECTION 1612 — COMBINATIONS OF LOADS 1612.1 General. Buildings and other structures and all portions thereof shall be designed to resist the load combinations specified in Section 1612.2 or 1612.3 and, where requited by Chapter 16, Division IV, oF Chapters 18 through 23, the special seismic load ‘combinations of Section 1612.4 ‘The most critical effect ean occur when one or more of the con- twibuting loads are not acting. All applicable loads shall be consid- cred, including both earthquake and wind, in accordance with the specified load combinations. 1612.2 Load Combinations Using Strength Design or Load ‘and Resistance Factor Design. 1612.2.1 Basic load combinations. Where Load and Resistance Factor Design (Strength Design) is used, structures and all por- tions thereof shell resist the most critical effects from the follow- ing combinations of factored loads: 14D «azay 12D + 1.61 +05 (ly oF S) (12.2) 12D +1.6 (L, of S)+ (f-or08W) (12-3) 12D + 13W4fL-+05 , or) (12d) 12D + 10E + iL +f25) 25) 09D + (LOE or 130) 2-6) WHERE: ‘A = 1.0 for loors in places of public assembly, for live loads in excess of 100 pst (4.9 kN/mn?), and for garage live load, = 05 for other tive loads. So = 0.7 for roof configurations (such as saw toot) that do not shed snow off the structure, = 0.2 for other roof configurations. EXCEPTIONS: 1, Facored load combinations for conrete per ‘Section 199.2 whee load combination do nat inclu seis forces. 2, Faciored lead combinations ofthis section ruliplied by 1. Tor concrete and masonry where load combinlions incinde seismic forces 2. Where other factored load combinations are specitically required by he provisions ofthis code 1612.2.2 Other loads, Where FH, P or Tare to be considered in design, each applicable load shall be added to the above combina tions factored as follows: 1.3F, 1.6H, 1.2P and 1.27. 1612.3 Load Combinations Using Allowable Stress Design. 1612.3.4 Basic load combinations, Where allowable stress design (working stress design) is used, structures and all portions ter sal ett ocr eect eu oe ig combats of en > an D+L+ (lors) (12-8) E ' D+ (we #) 29) 09 + 42-10) poorer dors + (woe 8] 210 No increase in sllowable stress shall be usod with these load combinations except as specially permitted by Setion 1808.2, 1612.32 Alternate basic load combinations. In licu ofthe basic load Combinations specified in Section 1612.3.1, structures and1997 UNIFORM BUILDING CODE portions thereof shall be permitted tobe designed for the most cit= ‘cal effects resulting from the following load combinations. When using these alternate basic load combinations, a one-third increase shall be permitted in allowable stresses for all combinations including Wor E. D+L+ bes 2412 pts (wor) ani) p+uews$ (214) D+L+see 2-45) plese (12-16) os « (2.160) EXCEPTIONS: 1, Crone hook londs need uot be combined with oof ive lon or with moce than thre fourths ofthe show Toad or one Elf ofthe wind oad. 2. Design sow loads of 30 ps (1.4 kN) ores ee ot be com bined with selmi eas. Whore design snow lous excoed 30 ps (14 [kNin?) the design soow load sal be ineludet wih seismic Hous, but may beredced upto 75 percent where consideration of siting, conti ‘ration and load duration warrant when approved by the building off al 1612.3. Other loads. Where FH, P or Tate 1 be considered in design, each applicable load shall be added to the combinations specified in Sections 1612,3.1 and 1612.3.2, When using the aler- CHAP. 15, DIV. era: 1613 nate load combinations specified in Section 1612.3.2, a one-thitd ‘nerease shall be permitted in allowable stresses forall combina- tions including W or E 1612.4 Special Seismie Load Combinations. For both Allow- able Stress Design and Strength Design, the following special load ‘combinations for seismic design shall be used as specifically required by Chapter 16, Division IV, or by Chapters 18 through 23; 12D + fil + 1.0Re az? 09D + 1.0K, (2-18) WHERE: ‘i = 100 for floors in places of public assembly, for live toads in excess of 100 psf (4.79 kN’m2), and for garage live. load. = 05 for other Toads. ‘SECTION 1613 — DEFLECTION ‘The deflection of any structural member shall not exceed the val- vues set forth in Table 16-D, based on the factors set forth in Table 16-E, The deflection criteria representing the most restrictive con dition shall apply. Deflection criteria for materials not specified shall be developed in a manner consistent with the provisions of this scetion. See Section 1611.7 for camber requirements. Span tables for light wood-frame construction as specified in Chapter 23, Division VIT, shall conform to the design criteria contained therein, For concrete, see Section 1909.5.2.6; for aluminum, see Section 2003; for glaring framing, see Section 2404.2,CHAP. 16, DIV.IL 614 Division ilI-SNOW LOADS SECTION 1614 — SNOW LOADS Buildings and other structares apd all portions thereof that are sub jeet to snow loading shall be designed to resist the snow loads, as determined by the building official, in accordance with the load ‘combinations set forth in Section 1612.2 07 1612.3. Potential unbalznced| socamulation of saow at valleys, paras peis, roof structures and offsets in roofs of uneven configuration shall be considered Snow loads in excess of 20 psf (0.96 KN?) may be reduced for cach degree of pitch over 20 degrees by Ry as determined by the formula: 1087 vvronut Bub CODE n- S-} any [: =~ rorsk n= aon ‘WHERE: Ry = snow load reduction in pounds per square foot (N/m?) per degree of pitch over 20 degrees. 'S- = total snow load in pounds per square foot (kN/mn?) For alseraate design procedure, where specifically adopted, see Appendix Chapter 16, Division I4997 UNIFORM BUILDING CODE ‘CHAP, 16, DIV Il 1615 10213 Division II-WIND DESIGN SECTION 1615 — GENERAL very building or structure and every portion thereof shall be de- signed and constructed to resist the wind effects determined in ac- ‘cordance with the requirements of this division. Wind shall be assumed to come from any horizontal direction. No reduction in wind pressure shall be taken for the shielding effect of adjacen structures. ‘Structures sensitive to dynamic effects, such as buildings with a hheight-to-width ratio greater than five, structures sensitive to ‘wind-excited oscillations, such as vortex shedding or icing, and ‘buildings over 400 feet (121.9 m) in height, shall be, and any strvc- ture may be, designed in eccordance with epproved national standards, “The provisions ofthis section do not apply to building and foun- ‘dation systems in those areas subject to scour and water pressure ‘by wind and wave action. Buildings and foundations subject to such Joads shall be designed in accordance with approved national standards. ‘SECTION 1618 — DEFINITIONS ‘The following definitions apply only to this division: BASIC WIND SPEED is the fastost-mile wind speed asso- ciated with an annual probability of 0.02 measured at a point 33 feet (10 000 min) above the ground for an area having exposure category C. EXPOSURE B has terrain with buildings, forest or surface ir- regularities, covering at least 20 percent ofthe ground level area exiending I mile (1.61 km) or more from the site EXPOSURE C has terrain that is flat and generally open, ex- tending #2 mile (0.81 km) or more from the site in any full quad- rant EXPOSURE D represents the most severe exposure in areas with basic wind speeds of 80 miles per hour (mph) (129 kaw) or ‘greater and has terrain that is flat and unobstructed facing large bo: dies of water over 1 mile (1.61 km) or more in width relative to any ‘quadrant of the building site. Exposure D extends inland from the shoreline %j mile (0.40 km) or 10 times the building height, whichever is greater. FASTEST-MILE WIND SPEED is the wind speed obtained from wind velocity maps prepared by the National Oceanographic ‘and Atmospheric Administration and is the highest sustained av- ‘erage wind spoed based on the time required for a mile-long sam- ple of air to pass a fixed point, OPENINGS are apertures or holes in the exterior wall bound ary of the structure. All windows or doors or other openings shall ‘be considered as openings unless such openings and their frames are specifically detailed and designed to resist the Toads on ele- ‘ments and components in accordance withthe provisions of this section, PARTIALLY ENCLOSED STRUCTURE OR STORY is a structure or story that has more than 15 pervent of any windward projected area open and the arca of opening on all other projected areas is less than half of that on the windward projection. SPECIAL WIND REGION is an area where local records and terrain features indicate 50-year fastest-mile basic wind speed is higher than shown in Figure 16-1 UNENCLOSED STRUCTURE OR STORY is a structure that has 85 percent or more openings on all sides. SECTION 1617 — SYMBOLS AND NOTATIONS “The following symbols and notations apply to the provisions of this division: Ce = combined height, exposure and gust factor coefficient as given in Table 16-G. Gy = pressure coefficient for the structure or poztion of struc ture under consideration as given in Table 16-H. importance factor as set forth in Table 16-K. design wind pressure. ge = wind stagnation pressure atthe standard height of 33 feet (10.000 mm) as set forth in Table 16-F. ‘SECTION 1618 — BASIC WIND SPEED “The minimum basic wind speed at smy site shall not be less than that shown in Figure 16-1, For those areas designated in Figure 16-1 as special wind regions and other areas where local records or terrain indicate higher 50-year (mean recurrence interval) fastest- ‘mile wind speeds, these higher Values shall be the minimum basic ‘wind speeds. ‘SECTION 1619 — EXPOSURE An exposure shall be assigned at each site for which a building or structure is to be designed. ‘SECTION 1620 — DESIGN WIND PRESSURES Design wind pressures for buildings and structures and elements therein shall be determined for any height in accordance with the following formule: P= Ce Cp dehy (20-1) SECTION 1621 — PRIMARY FRAMES AND SYSTEMS 1621.1 General, The primary frames or load-exstng system of every structure shal be designed forthe pressures calculated us- ing Formula (20-1) and the pressure costicients, Cy, of either Method 1 or Methed 2. In adition, design ofthe oral structure and its primary load-resisting system shall conform to Section 1608. ‘The base overturning moment forthe entire structure or for any cone ofits individual primary lateral-esisting elements, shall ot ‘exceed 0 thirds ofthe deuload-esisting moment. Foran entre structure with &heigh-to-width ratio of 0.5 or less in te wind i reetion and 2 maximums height of 60 feet (18 290 mn), the combi- ration of the effects of uplift and overturning may be reduced by one third. The weight of earth superimposed ever footings may be used to calculate the dead-foad-resisting moment 1621.2 Method 1 (Normal Foree Method). Method 1 shall be used forthe design of gabled rigid frames and may be used for any structure, In the Normal Force Method, the wind pressures shall be assumed to act simultaneously normal to all exterior surfaces. For pressures on roofs and leeward walls, C, shall be evaluated at the ‘mean rool height, 1621.3 Method 2 (Projected Area Method). Method 2 may be ‘used for any structureless than 200 feet (60 960 mm) in height ex- ‘cept those using gabled rigid frames. This method may be used in stability determinations for any structure less than 200 feet (60 960 mm) high. Inthe Projected Area Method, horizontal pres- ‘sures shall be assumed to act upon the full vertical projected arca ar(CHAP. 16, DIV T6218 1625) of the stricture, and the vertical pressures shall be assumed to act, simultaneously upon the full horizontal projected arcs. SECTION 1622 — ELEMENTS AND COMPONENTS OF STRUCTURES, Design wind pressures for each element or component of struc tute shall be determined from Formula (20-1) and Cy values from Table 16-H, and shall be applied perpencicular to the surface, For ‘outward acting forces the value of Cy shall be ebtsined from Table 16-G based on the mean roof height and applied for the entire Ineight of the structure, Bach element or component shall be de signed for the more severe ofthe following loadings: 1, ‘The pressures determined using Cy values for elements and ‘components acting over the entire tributary area of the elemeat. 2. The pressures determined using C, values for local areas at discontinuities such as corners, ridges and eaves. These local pres sures shall be applied over a distance from a discontinuity of 10 feet (2048 eam) or 0.1 times the least width of the structure, whichever is less. ‘The wind pressures from Sections 1621 and 1622 need not be combined, 1997 UNIFORM BUILDING CODE ‘SECTION 1623 — OPEN-FRAME TOWERS Radio towers and other towers of trussed construction shal be de- signed and constructed t0 withstand wind pressures specified in this section, multiplied by the shape factors set forth in Table 16H. ‘SECTION 1624 — MISCELLANEOUS STRUCTURES Greenhouses, lath houses, agricultural buildings or fences 12 feet (3658 mm) ot less in height shall be designed in accordance with Chapter 16, Division IT, However, three fourths of q,, but not less than 10 psf (0.48 kNim2), may be substituted for q, in Formula (20-1), Pressures on local areas at discontinuities need not be con- sidered, SECTION 1625 — OCCUPANCY CATEGORIES For the purpose of wind-tesistant design, vuch structure shall be placed ia one of the occupaney categories listed in Table 16-K. ‘Table 16-K lists importance factors, fy, for each category.41997 UNIFORM BUILDING CODE CHAP. 16, DIV. IV 3628 1627 Division IV—EARTHQUAKE DESIGN ‘SECTION 1626 — GENERAL 1626.1 Purpose. The purpose of the earthquake provisions herein is primarily to safeguard against major structural failures and loss ‘of life, not to limit damage or maintain function, 1626.2 Minimum Seismic Design. Structures and portions thereof shall, as @ minimum, be designed and constructed to resist the effects af seismic ground motions as provided inthis division 1626.3 Seismic and Wind Design, When the code-prescribed wind design produces greater effects, the wind design shall gov em, but detailing requirements and limitations prescribed in this section and referenced sections shall be followed ‘SECTION 1627 — DEFINITIONS. For the purposes ofthis division, certain terms ate defined as fol- lows: [BASE is the level at which the earthquake motions are consid- cred tobe imparted to the stucture or the level st which the stuc- ture asa dynamic vibrator is supported. BASE SHEAR, ¥ isthe total design leteral force oe shear atthe base of a structure BEARING WALL SYSTEM is a siructural system without a complete vettical load-carying space frame. See Section 1629.62. BOUNDARY ELEMENT is an clement at edges of openings or at perimeters of shear walls or diaphragms, BRACED FRAME is an essentially vertical truss system of the concentric or cocentrie type that is provide to resist lateral forces. BUILDING FRAME SYSTEM is an essentially complete space frame that provides suppor for gravity loads. See Section 1629.63. CANTILEVERED COLUMN ELEMENT js a column cle- meat in a laterahforce-resisting system that canlleyers from a fixed base and has minimal moment capacity atthe top, with iat- ral forces applied essentially at the top. COLLECTOR isa member or element provided to transfer lt- eral forces from a portion of a structure to vertical elements of the latcral-force-tesisting system. COMPONENT is» pert or clement of an architectural, electri- cal, mechanical o structural system. COMPONENT, EQUIPMENT, isa mechanical or electrical ‘component or clement tht is pat of'« mechanical andor electrical system, COMPONENT, FLEXIBLE, is a component, inctuding its attachments, having a fundamental period greater than 0.06 sec- ond COMPONENT, RIGID, is a component, including its atach- meats, having @ fuadamenial period less than or equal to 0.06 sec- ond. CONCENTRICALLY BRACED FRAME is a braced frame in which the members are subjecied primarily to axial forces. DESIGN BASIS GROUND MOTION is that ground motion that has a 10 percent chance of being exceeded in $0 yeas a deter- mined by a site-specific heard analysis or may be determined from a hazard map. A suite of ground motion time histories with dynamie properties representative of te site charactcristis shall be used to represent this ground motion. The dynamic effects of the Design Basis Ground Motion mey be represented by the Design Response Spectrum, See Section 1631.2, DESIGN RESPONSE SPECTRUM is an clastic response spectrum for $ percent equivalent viscous damping used to tepre~ sent the dynamic effects of the Design Basis Ground Motion for the design of structures in accordance with Sections 1630 and 1631. This response spectrum may be either a site-specific spec- trum based on geologic, tectonic, seismological and soil charac= teristics associated with a specifi site of may be a spectrum constructed in accordance with the spectral shape in Figure 16-3, using the site-specific values of C, and C, and mati acceleration of gravity, 386.4 in see? (94815 msec). See Sec- tion 1631.2. DESIGN SEISMIC FORCE is the minimum total strength de- sign base shear, factored and distributed in accordance with Sec- tion 1630. DIAPHRAGM is 2 horizontal or nearly ho {ng o transmit lateral fores to the verticaes term “diapheagm” includes horizontal bracing systems. DIAPHRAGM or SHEAR WALL CHORD is the boundary clement of a diaphragm or shear wall that is assumed to take axial stresses analogous to the flanges of a beam, DIAPHRAGM STRUT (crag strut, te, collector) isthe ete ‘ment of a diaphragm parallel to the applied load that collects and transfers diaphragm shear tothe vertical-resistng elements or dis- teibutes loads within the diaphragm. Such members may take axial, tension or compression. DRIFT. See “story dri.” DUAL SYSTEM is a combination of moment-resiting frames ‘and shear walls or braced frames designed in accordance withthe criteria of Section 1629.6.5. ECCENTRICALLY BRACED FRAME (EBF) is a siccl- bruced frame designed in conformance with Section 2213.10. ELASTIC RESPONSE PARAMETERS are forces and deformations determined from an elastic dynamic analysis using an unreduced ground motion representation, in accordance with Section 1630. ESSENTIAL FACILITIES are those structures that are nec- essary for emergency operations subsequent to a natural disaster FLEXIBLE ELEMENT ot system is one whose deformation under lateral load is significantly larger than adjoining parts ofthe system. Limiting ratios for defining specifi flexible elements ace set forth in Section 1630.6. HORIZONTAL BRACING SYSTEM is a horizontal truss system that serves the sume function asa disphragm. INTERMEDIATE = MOMENF-RESISTING FRAME, (MRE) isa concrete frame designed in accordance with Section 1921.8. LATERAL-FORCE-RESISTING SYSTEM js that part of, the structural system designed to resist the Design Seismic Frees, MOMENT-RESISTING FRAME is frame in which mem- bers and joints are capable of resising forces primarily by flexure MOMENT-RESISTING WALL FRAME (MRWE) is 2 rmasoary wall fram especially detailed to provide ductile behay- for and designed in conformance with Section 2108.25, ORDINARY BRACED FRAME (ORE) is a steel-braced frame designed in secordance with the provisions of Section 28CHAP. 16, DIV. IV ‘1627 1628 22138 or 2214.6, or concrete-braced frame designed in accord- ‘ance with Section 1921, ORDINARY MOMENT-RESISTING FRAME (OMRF) is a moment-resisting frame not meeting special detailing requite- ‘ments for ductile behavior. ORTHOGONAL EFFECTS are the earthquake load effects, ‘on structural elements common to the lateral-force-resisting syS- tems along two orthogonal axes. OVERSTRENGTH is a characteristic of siructures where the actual strength is larger than the design strength. The degree of ‘oversizengih is material and system-dependent. PA BEFECT is the secondary effect on shears, axial forces and ‘moments of franie members induced by the vertical loads geting ‘on the faterally displaced building system. SHEAR WALL is a wall designed to resist lateral forces paral- Jel to the plane of the wall (sometimes referred to as vertical dia- phragm or structural wall). SHEAR WALL-FRAME INTERACTIVE SY: uses ‘combinations of shear walls and frames designed to resist lateral forces in proportion to their relative rigidities, considering inter- action between shear walls and frames on all levels SOFT STORY is one in which the leteral stiffness is less than 70 percent of the stiffness of the story above. See Table 16-L. SPACE FRAME is a three-dimensional structural system, without bearing walls, composed of members interconnected so as fo function 28 a complete self-contained unit with or without the aid of horizontal diaphragms or floo‘-bracing systems. SPECIAL CONCENTRICALLY BRACED FRAME (SCBP) is. steel-bruced frame designed i conformance with the provisions of Section 2213.9. SPECIAL MOMENT-RESISTING FRAME (SMRF) is a mwoment-resisting frame specially detailed to provide ductile bebavior und comply with the requirements given in Chapter 19 0r22. SPECIAL TRUSS MOMENT FRAME (STMF) is a ‘momentzesisting frame specially detailed to provide ductile ‘behavior and comply with the provisions of Section 2213.11. STORY is the space between levels. Story xis the story below Level x STORY DRIFT is the lateral displacement of one level relative to the level above or below. STORY DRIFT RATIO is the story drift divided by the siory height. STORY SHEAR, Vz, is the summation of desiga lateral forces above the story under Consideration. STRENGTH is the capacity of an element or a member to resist factored load as specified in Chapters 16, 18, 19, 21 and 22. STRUCTURE is an assomblage of framing members designed 1 support gravity loads and resist lateral forces. Structures may be categorized as building structures or nonbuilding structures. SURDIAPHRAGM js a portion of a larger wood diaphragm, designed to anchor and transfer local forees to primary diaphragm struts and the main diaphragm. VERTICAL LOAD-CARRYING FRAME is a space frame designed to carry vertical gravity loads. WALL ANCHORAGE SYSTEM is the system of elements, anchoring the wal wo the diaphragm and those clemeats within the diaphragm required to develop the auchorage forees, including 240 +1007 UNIFORM BUILDING CODE subdiaphragms and continuous ties, as specified in Sections 1633.2.8 and 1633.29. WEAK STORY is one in which the story strength i Jess than, 80 percent ofthe story above. See Table 16-L. ‘SECTION 1628 — SYMBOLS AND NOTATIONS: ‘The following symbols and notations apply to the provisions of ‘his division: ‘Ay. = ground floor area of strucure in square fect (a?) 0 include area covered by all overhangs and projec- tions. ‘Ac = the combined effective area, in square fect (m”), of the shear walls in the first story ofthe strate, ‘he minimum cross sectional are in any horizontal plane in the first story, in square feet (m*) of a shcar wall F ‘Ag. = the torsional amplification factor at Level x = numerical coefficient spectied in Section 1632 and set forth in Table 16-0. seismic coeficient, 8 st forth in Table 16-0. = numerical coefficient given in Section 16302.2. seismic encticen, a set forth in Table 16-R dead load one stueturl element the length, in feet (m), of @ shear wal in the frst story in the direction parallel to the applied forces. Ae Eq Ey = earthquake loads set forth in Section 1630.1. F = Design Seismic Force applied to Level i, 1 ot % respectively. F,, = Design Seismic Forces on a patt of the structure. Foe = Design Seismic Force on a diaphragm. F, = that portion of the base shear, V, considered concen- trated at the top of the structure in addition to Fy. lateral force at Level i for use in Formula (30-10). acceleration due to gravity. bbeight in feet (m) above the base to Level i, n of respectively importance factor given in Tuble 16-K. importance factor specified in Table 16-K. live load on a structural element. level of the structure referced to by the subscript é f= 1” designates the fist Ievel above the base. Level n = that level that is uppermost in the main portion of the structure, tht Level that is under design consideration. “x= 1” ‘designates the first level above the base. ‘maximum moment magnitude. near-source factor used in the determination of Cy in Scismie Zone 4 related to both the proximity of the building o: structure to known faults with magnitudes and slip rates as set forth in Tables 16-S and 16-U. Ny = neur-source factor used in the determination of G, in Seismic Zone 4 relsted to botb the proximity of the building or structure to known faults with magnitudes ‘and slip rates as sot forth in Tables 16-T and 16-U,1997 UNIFORM BUILDING CODE PI = plasticity index of soil determined in accordance with approved national standards, R = numerical coefficiont representative of the inherent overstrength and global ductility capacity of lateral- force-tesisting systems, as set forth in Table 16-N or IGP. 7 = aratio used in determining p. See Section 1630.1 Sa Se. Sc, Sp, ‘Sg, Sp_= soil profile types as set forth in Table 16-1. T= elastic fundamental period of vibration, in seconds, ‘ofthe strveture inthe diretion under consideration. the tual design lateral force or shear a the base given by Formula (30-5), (30-6), (30-7) or 0-11. Vx © the design story shear in Story x W = the total seismic dead load defined in Section 1630.11 vise = that portion of W located a o assigned to Level For, respectively. 1650.11. that portion of W located at or assigned to Level or respectively ‘other loads defined in Section 1630.11 seismic zone factor as given in Table 164 Maximum Inelastic Response Displacement, which is the total drift or total story drift that occurs when the structure is subjected fo the Design Basis Ground Motion, including estimated elastic and inelastic contributions tothe total deformation defined in See- tion 1630.9. ‘As = Design Level Response Displacement, which is the total drift of total story drift that occurs when the structure is subjected tothe design seismic forces. {= horizontal displacement st Level relative to the base due to applied lateral forces, f. for use in Formula 60-10). p= Redundancy/Relibility Factor given by Formula 0-3. , = Seismic Force Amplification Factor, which is requires to account for structural oversrength and set forth in Table 16. wp Ws ‘SECTION 1629 — CRITERIA SELECTION 1629.1. Basis for Design, The procedures and the limitations for the design of structures shall be determined considering seismic ‘zoning, site characteristics, occupancy, configuration, structural ‘system and height in accordance with this section, Structures shall be designed with adequate strength to withstand the lateral dis- placements induced by the Design Basis Ground Motion, consid- fering the inelastic response of the structure and the inherent redundancy, overstrength and ductility of the Tateral-force- resisting system, The minimum design strength shall be based on the Design Seismic Forves determined in accordance with the static lateral force procedure of Section 1630, except as modified ‘by Section 1631.5-4. Where strength design is used, the load com= binations of Section 1612.2 shall apply. Where Allowable Stress Design is used, the Toad combinations of Section 1612.3 shall apply. Allowable Stress Design may be used to evaluate sliding or ‘overturning at the soil-strucure interface regardless of the design approach used in the design of the strueture, provided load com- ‘CHAP, 16, DIV. IV 628 1629.81 binations of Section 1612.3 are utilized. One- and two-family dwellings in Seismic Zone 1 need not conform to the provisions of this section, 1629.2 Occupancy Categories. For purposes of carthquake- resistant design, each structuce shall be placed in one of the occu- ppancy catogories listed in Table 16-K. Tuble 16-K assigns impor- tance factors, Fand Jp, and structural observation requirements for each category. 1629.3 Site Geology and Soil Characteristies. Each site shall ‘be assigned a soil profile type based on properly substantiated gootechnical data using the site categorization procedure set forth in Division V, Section 1636 and Table 164 EXCEPTION: When te sol properdes se not known i sien ‘ati detemine the sol prot type, Type Spy shall be wed, Soi Pro- file Type Sy or Sr aced not be seamed unless the bulding official ‘determines hat Type Sof Se may be present atthe site o in the event ‘that Type Se or Sp established by geotectnics ds, 1629.3.1 Soil profile type. Soil Profile Types Sa, Sp, Se, Sp and ‘Sg are defined in Table 16-1 and Soil Profile Type Sy is defined as sobs S's ‘Se are defined in Table 16-1 and Soil Profile Type Sp is defied as ‘soils requiring site-specific evaluation as follows: 2, Beats andior highiy organic clays, where the thickness of peat or highly organic clay exceeds 10 feet (3048 mm). 3. Very high plasticity clays with a plasticity index, PZ > 75, where the depth of clay exceeds 25 feet (7620 mmm). 4, ery thick sofVmedium stiff clays, where the depth of clay exceeds 120 feet (36 576 mm), 162944 Site Seismic Hazard Characteristics. Seismic hazard ‘characteristics for the site shall be established based on the seis- ‘mic zone and proximity of the site to active seismic sources, site soil profile characteristics and the structure's importance factor. 1629.4.1. Seismic zone, Bach site shall be assigned a scismic zone in accordance with Figure 16-2. Each structure shall be assigned a seismic zone factor Z, in accordance with Table 16-1 1629.4.2 Seismic Zone 4 near-source factor: In Seismic Zone 4, ‘each site shall be assigned a near-source factor in accordance with Table 16-S und the Seismic Source Type set forth in Table 16-U. ‘The value of N, used (0 determine C, need not exceed 1.1 for structures complying with all the following conditions: 1. The soil profile type is Ss, Sg, Se OF Sp. 2 p=10. 3. Except in single-story structures, Group R, Division 3 and Group U, Division 1 Occupancies, moment frame systems desig nated as part of the lteral-force-resisting system shall be special moment-resisting frames, 4. The exceptions to Section 2213.7.5 shall not apply, except {or columns in one-story buildings or columns at the top story of ultistory buildings. 5S. None of the following structural iregularities is present: ‘Type 1, 4or Sof Table 16-L, and Type | or 4 of Table 16-M 1629.4.3 Seismic response eoefficients. Each structure shall be assigned a seismic coeificient, Cy, in accordance with Table 16-Q. ‘and a seismic coefficient, C, in accordance with Table 16-R. 1629.5 Configuration Requirements. 1629.5.1 General. Each structure shall be designated as being structurally regular or irregular in accordance with Sections 1629,5.2 and 1629.53, atHAP. 16, DIV.IV ‘e982 162982 1629.52 Regular structures. Regular structures have no sig~ nificant physical discontinuitis in plan or vertical configuration ‘or in their latoral-force-resisting systoms such asthe iegular fes- tures described in Seetion 1629.5.3. 1620.5.3 Irregular structures. 1. Tregular structures have significant physical discontinuities, {n configuration or in thei lateral-force-resisting systems, Iiregu- Tar features include, but are not limited to, those described in ‘Tables 16-L and 16-M, All structures in Seismic Zone 1 and Ocev- ancy Categories 4 and 5 in Seismic Zone 2 need to be cvaluated ‘only for vertical iregulatities of Type 5 (Table 16-L,) and horizon- tal iregulacities of Type | (Table 16-M). 2. Structures having any ofthe features listed in Table 16-L shall be designated as if having a vertical irregularity EXCEPTION: Where no story dit ctio under design Iterat ores i greater Chan 13 tes the story drift ro ofthe story above, the ssn may be deemed o ot havethe stuctaral regulates of| ‘Type | of 2in Table 16. The story det ratio forthe top two stories ed not he considered, Ths sory det for his determination may be ‘alla neglecting torsional effets. 3, Structures having any of the features listed in Table 16-M stall be designated as having a plan irregulaity. 1629.6 Structural Systems. 1629.6.1 General. Structural systems shall be classified as one ‘of the typos listed in Table 16-N and defined in this scction, 1629.6.2. Bearing wall system. A structural system without a complete vertical load-carrying space frame. Bearing walls or bracing systems provide suppost far all or most gravity loads. Re- sistance to Lateral load is provided by shear walls or braced frames. 1629.6.3 Building frame system. A structural system with an cesentially complete space frame providing support for gravity loads, Resistance to lateral load is provided by shear walls or braced frames. 1629.64 Moment-resisting frame system. A structural system with an essentially complete space frame providing support for gravity loads, Moment-resisting frames provide resistance to Iat- eral load primarily by flexural action of members. 1629.65 Daal system. A structural system with the following features: 1. An essentially complete space frame that provides support for gravity loads, 2. Resistance to lateral loud is provided by shear walls or braced frames and moment-resistng frames (SMRF, MRF, MMRWF or steel OMRF). The moment-resisting frames shall be designed 10 independently resist at least 25 percent of the design base shear, 3, The two systems shall be designed to resist the total desi ‘base shear in proportion to their relative rigidities considering the interaction of the dual system at all levels. 1629.6.6 Cantilevered column system. A. structural system relying on cantilevered column elements for lateral resistance. 1629.6.7 Undefined structural system. A structural system not listed in Table 16-N, 1629.6.8. Nonbuilding structural system. A structural system ‘conforming to Section 1634, 1629.7 Height systems in Seismic Zones 3 and 4 arc given me its, Height limits for the various stractural rable 16-N, 41997 UNIFORM BUILDING CODE EXCEPTION: Regular structures may exceed these mis by pot more than 30 pereet for utcorepied sractres, which armor acest be tothe general public. 1629.8 Selection of Lateral-torce Procedure. 1629.8.1 General. Any structure may be, and certain structures ‘defined below shall be, designed using the dynamic lateral-force procedures of Section 1631, 1629.8,2 Simplified static. The simplified static lateral-force procedure set forth in Section 1630.2.3 may be used for the fol- owing structures of Occupancy Category 4 ot 5 1. Buildings of any occupancy (including single-family dell ngs) not more than three stories in height excluding basements, that use light-frame construction, 2, Other buildings not more than two stories in height exclud- ing basements. 1629.83 Static. The static lateral force procedure of Section 1630 may be used for the following structures: 1. All siracures, regular o¢ irregular, in Seismic Zone ¥ and in ‘Occupancy Categories 4 and 5 in Seismic Zone 2. 2, Regular structores under 240 feet (73 152 mm) in height with lateral force resistence provided by systems listed in Table IGN, except where Section 1629.8.4, Item 4, applies. 3, Irregular structures not more than five stories or 65 fect (49.812 mm) in height. 4, Structures having a flexible upper portion supported on a ‘gid lower portion where both portions of the structure consid- ‘ered separately can be classified as being regular, the average sory slifiness of the lower portion is atleast 10 times the average story stiffness of the upper portion and the period of the entire structure is ot greater than 1.1 times the period ofthe upper por- tion considered as a separate sincture fixed at the base, 1629.84 Dynamic. The dynamic lateral-foree procedure of ‘Section 1631 shall be used forall other structures, including the following: 1. Structures 240 feet (73 152 mm) or more in height, except as permitted by Section 1629.83, Ttem 1 2. Structures having a stiffness, weight or geometric vertical ir- regularity of Type 1, 2or 3, as defined in Table 16-L, or structures having irregular features not described in Table 16-L or 16-M, x- ‘cept as permitted by Scotion 1630.4 3, Structures over five stories or 65 feet (19 812 mm) in height in Seismic Zones 3 and 4 not having the same structural system throughout their height except as permitted by Section 1630.42, 4. Structures, regular or imegular, located on Soil Profile Type Sp. that have a period greater than 0.7 second, The analysis shall include the effects of the soils at the site and shall conform to Sec- tion 1631 2, Tiem 4. 1629.9 System Limitations, 1629.9.1 Discontinuity. Structures with a discontinuity in ca- pacity, vertical iregularity Type 5 as defined in Tule 16-L, shall ‘not be over two stories or 30 feet (9144 mm) in height where the weak story has 2 calculated surength of less than 65 percent of the slory above. EXCEPTION: Where he wes story is eqpahle of resisting aol tater seismic fore of 2 rmes the design fore prescribed in Section 1630, 1629.9.2 Undefined structural systems. For undefined struc- tural systems not listed in Table 16-N, the coofficient R shall be substantiated by approved eyclic test dats and analyses. The fol Towing items shall be addressed when establishing R:1997 UNIFORM BUILDING CODE 1, Dynamic response characteristics, 2, Lateral force resistance, 3. Overstrength and strain hardening or softening, 4, Strength and stiffness degradation, 5, Energy dissipation characteristics, 6, System ductility, and 7, Redundancy. 1629.93 Irregular features. All structures having irregular feauures described in Table 16-L or 16-M shall be designed wo meet the additional requirements of those sections referenced in the lables. 1629.10 Alternative Procedures. 1629.10.1 General. Altemalive lateral-force procedures using. ‘ational analyses based on well-established principles of mechan- ies may be used in lieu of those prescribed in these provisions. 1629.10.2 Scismic isolation. Seismic isolation, energy dissipa- tion and damping systems may be used in the design of structures ‘when approved by the building official and when special detailing is used (0 provide results equivalent to those obisined by the use of ‘conventional structural systems. For alternate design procedures ‘on seismic isolation systems, refer to Appendix Chapter 16, Di sion IN, Earthquake Regulations for Seismic-isolated Structures. SECTION 1630 — MINIMUM DESIGN LATERAL FORCES AND RELATED EFFECTS 1630.1 Earthquake Loads and Modeling Requirements. 1630.1.1 Earthquake londs, Structures shall be designed for ‘ground motion producing structural response and seismic forces in any horizontal direction. The following earthquake loads shall ‘be used in the loed combinations set forth in Section 1612: E=p +k Gon) Fn = E G02) ‘the earthquake Toad on an clement ofthe structure result- i from the combination ofthe horizontal component, Fp, and the vertical component, Ey ‘the earthquake load du tothe base shear, V, 9s set forth in Section 1630.2 othe design lateral fore, Fp, as Set forth in Section 1632. Eq = the estimated maximum earthquake force that can be developed in the structure as set forth in Section 1630.11 E, = the lod effect resulting from the vertical component of the earthquake ground motioa and is equal to an addition of O5CyID to the dead Toad effect, D, for Strength Design, and may be taken as zero for AMlowable Stress Design Q, = the scismic fores amplification factor that is required account for strctural overstrength, as Set forth in See tion 1630.31 = Retsblity/Redundancy Factor as given by the flow. ing form: p= 2- 2 G03) CHAP. 16, iv.ty ig29.0.2 1630-1. For SI: e-2 Tous Vs WHERE: ‘az = the maximum element-story shear rato, For a given di rection of loading the element-story shea ato i the ae tio of the design story shear in the most heavily loaded single element divided by the total design story shear. For any given Story Level , he elemeni-siory sheer r- tio is denoted as n. The maximum clement-story shear ratio Fg 8 defined asthe largest ofthe element story shear ratios, 7, which oceus in any ofthe story levels at ‘or below the two-thirds height level ofthe building, For braced frames, the value of 7 is equal to the maximum hori- zontal force component in a single brace element divided by the total story shear. For moment frames, shall be tken as the maximum of the sam of the shears in any two adjacent columns in a moment frame bay divided by the story shear. For columns commen to two bays ‘with moment-resisting connections on opposite sides at Level iin the direction under consideration, 70 percent of the shear in thet column may be used in the column shear surnmation For shoar walls,» shall be taken as the maximum value ofthe product of the wall shear multiplied by 10/ (For: 3.05/ty) and divided by the total story shear, where fy is the length ofthe wall in feet (m) For dual systems, 7 shall be taken asthe maximum value of 7 as defined above considering all lateral-load-resisting elements. The lateral foads shall be distributed to elements based on relative ri- cities considering the interaction of the dual system. For cual systems, the value of p need not exceed 80 percent of the value alate above, p shall not be taken less than 1.0 and need not be greater than 1,5, and 4g is the ground floor area of the structure in square feet (on2). For special moment-resisting frames, except when used in dual sysioms, p shall not exceed 1.25. The number of bays of spe- cial moment-esistng frames shal be increased (o reduce 7 such that pis less than or equal to 1.25. EXCEPTION: Ay may be ten asthe average flor are in the per seiback prion of the bing where a larger base area exit st the ground oor ‘When calculating drift, or when the structure is Tocated in Seis- mic Zone 0, 1 or 2, p shall be taken equal to 1 ‘The ground motion producing lateral response and design seis- ‘mie forees may be assumed to act nonconcurrently in te direction of each principal axis of the structure, except as required by Sec- tion 1633.1 Seismic dead load, W. is the total dead load and applicable por- tions of other loads fisted below. 1. In storage and warchouse occupancies, a minimum of 25 petceat of the floor lve load shall be applicable. 2. Where a partition load is used in the floor design, a load of not less than 10 psf (0.48 KN/in?) shall be incladed. 3. Design snow loads of 30 psf (1.44 kN/m?) or less need not be {included Where design snow loads exceed 30 psf (1.44 kN/n?), the design snow load shall be included, but may bg reduced up 10 75 percent where consideration of siting, configuration and load aration warrant when approved by the building official. 4, Total weight of permanent equipment shall be included. 1630.1.2 Modeling requirements. The mathematical model of the physical structure shall include all elements of the lateral- forco-resisting system. The model shall also incluge the stiffness aaa(CHAP. 16, DIV.IV 1630.1.2 y6002 and strength of elements, which ave significant tothe (of forces, and shall represent the spatial distribution of the mass nd stiffness of the structure, {n addition, the model shall comply ‘with the following: 1, Stiffness properties of reinforced concrete and masonry ele- ‘ments shall consider the effects of cracked sections. 2. For steel moment frame systems, the contribution of panel zone deformations to overall story drift shall be included. 1630.13 PA fects. ‘The resulting member forces and moments tnd the story drifis induced by PA effects shall be considered in the eveluation of overall structural frame stability and shall be evaluated using the forces producing the displacements of A. PA need not be considered when the ratio of secondary moment 10 pi ‘mary moment does not exceed 0.10; the ratio may be evaluated for ‘any story a8 the product of the total dead, floor live and snow load, ‘as required in Section 1612, above the story times the seismic drift in that story divided by the product of the seismic shear in that Story times the height of that story. In Seis Band 4, PAL need not be considered when the story drift ratio does not exceed o.oz/R. 1630.2 Static Foree Procedure. 1630.2.1. Design base sheur, The total design hase shear in a ‘given direction shall be determined from the following formula: Gt s 30-4) v= gph Gedy ‘The total design base sheer need not exceed the following: 25 G1 Ww Gos) ‘The total design base shear shall not be fess than the following: v= oncsw 30-6) In addition, for Seismic Zone 4, the otal base shear shall also aot be less than the following 08 NI 4, “aw 1630.22 Structure period. The value of 7 shall be detormined rom one of the following methods: 1, Method A: For all buildings, the value T may be approxi- ‘mated from the following formu: ve G0 T = CG) @0-8) WHERE G, = 0.035 (0.0853) for stee] moment-resisting frames. C, = 0.030 (0.0731) for reinforced concrete moment-resist ing frames and eccentrically braced frames. C, = 0.020 (0.0488) for all other buildings. Alternatively, the value of C; for situctures with concrete or ma- sonry shear walls may be taken as 0.1/ YA, (For Sk: 0.0743/ JA, for in m2). he value of Ac shall be determined from the following for- aula: Ay = ¥4,J02 + (Do/hs)*| 0-9) ‘The value of Dein used in Formula (30-9) shall not exceed 0.9. Pary +1997 UNIFORM BUILDING CODE 2. Method B: The fundamental period 7 may be calculated ws- ing the structural properties and deformational characteristics of the resisting elements in a properly substantiated analysis. The analysis shall be in accordance with the requirements of Section 1630.1.2. The value of T from Mothod B shall not excced a value 30 percent greater than the value of 7 obtained from Method A in Seismic Zone 4, and 40 percent in Seismic Zones 1, 2and 3. The fundamental period T may be computed by using the fol- owing formula: “ECE ‘The valves of f represent any lateral force distributed approxi- ‘mately in accordance with the principles of Formulas (30-13), (0-14) and (30-15) or any other rational distribution. The elastic deflections, é, shall be calculated using the applied tateral forces, fi. 1630.2.3 Simplified design base shear. 1630,2.3.1 General. Structures conforming to the requirements of Section 1629.8.2 may be designed using this procedure. 1630.2.3.2 Base shear, The total design base shear in a given a At each level designated as x, the force F, shall be applied over the area ofthe building in accocdance with the mass distribution at that level. Structural displacements and design seismic forces shall be calculated as the effect of forces F, and F, applied at the uppropriate levels above the base. 1630.6 Horizontal Distribution of Shear. ‘The design story ‘soar, Vj in any story is the sum of the forces F, and Fy above that story. Ve shall be disisibuted to the various elements of the vertical Iateral-force-resisting system in proportion to their rigidities, con- sidering the rigidity of the digphragm. See Section 1633.2.4 for ‘gid clements thal are not intended to be part ofthe lateral-foree~ resisting systems. ‘Where diaphragms are not flexible, dhe mass at exch level shall be assumed to be displaced from the calculated center of mass in cach direction a distance equal to 5 percent of the building dimen- ‘ion at that level perpendicular tothe dizection of the force under consideration, The effect ofthis displacement on the story shear distribution shall be considered. Diaphragms shall be considered flexible forthe purposes of vis tsibution of story shear and torsional moment when the maximum latoral deformation of the diaphragm is more than two times the average story drift of te associated story. This may be determined bby comparing the computed midpoint in-plane defleetion of the lapis ise under lateral load with the story dit of adjoining verlical-esisting elements under equivalent tibutary lateral load 1630.7 Horizontal Torsional Moments. Provisions shall be ‘made forthe increased shears resulting from horizontal torsion ‘where diaphragms are no flexible. The most severe load combi- nation foreach element shal be considered for design. ‘The torsional design moment aia piven story shall be the mo- iment resulting from cecenticities between applied design lateral forces at levels above that story and the veriabresistingelemenis in that story plus an accidental torsion ‘The accidental torsional moment sall be determined by assum- ing the mass is displaced a requited by Section 1630.6. ‘Where torsional regularity exists, as defined in Table 16-M, {he offsets shall be acoounted for by increasing the accidental tor. sion at each level by an amplification factor dy, determined from the fallowing formal an [es] WHERE: Sing = the average of the displacements atthe extreme points of the structure at Level x Spar = the maximum displacement at Level x ‘The value of Ay need not exceed 3.0 16308 Overturning, 1630.8.1 General. Every structure shall be designed to resist the overtuming effects caused by earthquake forces specified in Sec- tion 1630.5. At any level, the overtuming moments to be resisted shall be determined using those seismic forces (Fy and F,) that act ‘on levels above the level under consideration. At any level, the in- 20-15) 0-16) 245guap. 16, DIV.IV Ye30. ot] cremental changes of the design overturning moment shall be dis- tributed to the various resisting elements in the manner prescribed in Section 1630.6, Overturning effects on every element shall be Carried down to the foundation, Sce Sections 1615 und 1633 for ‘combining gravity and seismic forces, 1630.8.2 Elements supporting discontinuous systems. 1630,8.2.1 General. Where any portion of the tateral-load- resisting system is discontinuous, such as for vertical irregularity ‘Type 4 in Table 16-L or plan imegularity Type 4 in Table 16-M, ‘concrete, masonry, steel and wood clements supporting such dis continuous systems shall have the design strength to resist the ‘combination loads resulting from the special seismic load com- binations of Section 1612.4. EXCEPTIONS: |. The quantity in Section 1612.6 need not exceed he maximum fore tht can be austere tothe eet by ihe tsteral-forcetesising system. 2, Concrete slabs suppomting light-frame wood shear wall ystems corlight-nune sel and wood stctral panel shear wall systems, For Allowable Stress Design, the design strength may be detor- rined using an allowable siress increase of 1.7 and a resistance factor, @, of ].0. This inerease shall not be combined with the one- third stress increase permitted by Section 1612.3, but may be com bined with the duration of load increase permitted in Chapter 23, Division HL. 1630.8.2.2 Detailing requirements in Seismic Zones $ and 4. ‘Seismic Zones 3 and 4, elements supporting discontinuous sys- tems shall meet the following detailing or member limitations: 1, Reinforced concrete or reinforced masonry elements ‘designed primarily as axial-load members shall comply with Sec- tion 1921445, 2, Reinforced concrete elements designed primarily as flexural ‘members and supporting other than light-trame wood shear wall systes or light-fzame stoc] and wood structural panel shear wall systems shall comply with Sections 1921.32 and 1921.33. Strength computations for portions of slabs designed as support- ing elements shall include only those portions ofthe slab that com- ply with the requirements of these sections. 3. Masonry elements designed primarily as axial-load carrying ‘mombers shall comply with Sections 2106.1.12.4, Item 1, and. 2108.2.6.2.6 4. Masonry elements designed primacily as flexural members shalt comply with Section 2108,2.6.2.5 5, Steel clements designed primarily as axial-load members shaill comply with Seotions 2213.5.2 and 2213.5:3. 6, Steal elements designed primarily as flexural members or trusses shall have bracing for both top and bottom beam flanges or chords at the location of the support of the discontinuous system. ‘and shall comply with the requirements of Section 2213.7.1.3, 7, Wood elements designed primarily 2s flexural members shall be provided with lateral bracing or solid blocking st each end of the clement and at the connection location(s) ofthe discontinuous system, 1630.83 At foundation. See Sections 1629.1 and 1809.4 for ‘overturning moments to be resisted at the foundation soil inter face, 1630.9 Drift. Drift or horizontal displacements of the structure shall be computed whete required by this code. For both Allow- able Stress Design and Strength Design, the Maximam Inclastic Response Displacement, Ay, of the structure caused by the Design Basis Ground Motion shall be determined in accordance with this section. The difis corresponding to the design seismic 216 1907 UNIFORM BUILDING CODE forces of Section 1630.21, As, shall be determined in eccordance ‘with Section 1630.9.1, To determine Ay, these drifts shall be ‘amplified in accordance with Section 1630.9.2. 1630.9.1 Determination of As. A static, elastic analysis of the lateral force-tesisting system shell be prepared using the design seismic forces from Section 1630.2.1. Alternatively, dynamic analysis may be performed in accordance with Section 1631. Where Allowable Stress Design is used and where drift is being ‘computed, the load combinations of Section 1612.3 shall be used. ‘The mathematical model shall comply with Section 1630.1.2. The resulting deformations, denoted as As, shall be determined at all critical locations in the structure. Calculated drift shall include ‘wanslational and torsional deflections, 1630,9.2 Determination of Aj, ‘The Maximum Inelastic Response Displacement, Ay, shall be computed as follows: Ay = 07 RAs (30.17) EXCEPTION: Alematively, yg may be computed by acainear time history analysis in acontance with Section 1631.6 ‘The analysis used (0 determine the Maximum Inelastic Response Displacement Ay shall consider PA effects. 1630.10 Story Drift Limitation. 1630.10.1 General. Story drifts shall be computed using the Maximum Inelastic Response Displacement, Ay. 1630.10.2 Calculated. Calculated story drift using Ay shall not exceed 0.025 times the story height for structures having a funda- ‘mental period of less than 0.7 second, For structures having a fun- ‘damental period of 0.7 second or greater, the calculated story drift shall not exceed 0.020 times the story height, ‘EXCEPTIONS: |. These dif limits may be exceeded when cis demensirated that reer drift can be tolerate by bth socal ele= ‘ents sod nonstructural elements hat cook ales life safety. The de ted inthis assessment shall be based upon the Masia Inelastic [Response Displacement, Au 2. There sal be oo i init in single story steered structres lasted s Groupe B, F and S Ooeupances ee Group H, Division + ‘or3 Gcexpancies ln Groups B, F and Oceopancies, the pimary we Sal be miedo storage, factories or workshops. Minor accessory {ses sal be allowed in accordance with the provisions of Section 202 Sirctareson hic this exeoption is sed shall nt have pment t= tached tthe stot rene o¢ shal ave sh equipment detailed 0 ccoramdais the cine ci, Walls hat ae lrlly supported by the sel frame shall be designed 0 accomodate the dit in accor dance with Section 1633.24. 1630.10.3 Limitations, The design latcral forces used to deter- ‘mine the calculated drift may disregard the limitations of Formula (30-6) and may be based on the period determined from Formula (30-10) neglecting the 30 or 40 percent limitations of Section 1630.2. lem 2. 1630.11 Vertical Component. The following requirements ap- ply in Seismic Zones 3 and 4 only. Horizontal cantilever compo- ‘ents shall be designed for a net upward force of 0.7Cgi Wp. In addition to all other applicable load combinations, horizontal prestressed components shall be designed using not more than 50 ‘pereent of the dead load for the gravity load, alone or in combini tion with the lateral force effects. ‘SECTION 1631 — DYNAMIC ANALYSIS PROCEDURES 1631.1 General. Dynamic analyses procedures, when used, shall conform to the criteria established in this section. The analy sis shal be based on an appropriate ground motion representation ‘and shall be pecformed using accepted principles of dynamics.1997 UNIFORM BUILDING CODE ‘Structures that are designed in eocontance with this section shall ‘comply with all other applicable requitements ofthese provisions. 1631,2 Ground Motion. The ground motion representation shall, asa minimum, be one having a 10-percent probability of be- ing exceeded in 50 years, shall not be reduced by the quantity R and may be one ofthe following: 1. An clastic design response spectrum constructed in wevord- ance with Figure 16-3, using the Values of Cy and C, consistent With the specific site. The design acceleration ordinates shall be tmuplicd by the acceleration of gravity, 386.4 in/sec? (0.815 mise). 2. Asite-specific elastic design response spectrum based on the geologic, teclonic, seismologic and soil characteristics associated ‘with the specific site. The spectrum shall be devcloped for a damp- ing ratio of 0.05, unless a different value is shown fo be consistent ‘with the anticipeted structural behavior at the intensity of shaking ‘established for the site 3. Ground motion time histories developed forthe specific site shall be representative of actual earthquake motions. Response spectra from time histories, either individually or in combination, shall approximate the site design spectrum conforming to Section 1631.2, Item 2. 4, For structures on Soil Profile Type Sp, the following require- cuts shall apply when required by Section 1629.8.4, Item 4 4.1. The ground motion representation shall be developed i accordance with Items 2 and 3. 4.2. Possible amplification of building response due to the elfects of soil-structure interaction und lengtheniag of building period caused by inelastic behavior shall be considered 5. The vertical component of ground motion may be defined by scaling corresponding horizontal accelerations by a factor of two thirds, Alternative factors may be used when substantiated by site- specific data. Where the Near Source Factor, Na is greater than 1LO, site-specific vertial response spectra shall be used in liew of the factor of two-thirds. 1631.3 Mathematical Model. A mathematical model of the physical structure shall represent the spatial distcibution of the mass and stiffness ofthe structure to an extent that is adequate for the calculation ofthe significant features of its dynamic response. ‘A three-dimensional mode! shall be used forthe dynamic analysis ff structures with highly irregular plan configurations such as those having a plan istegularity defined in Table 16-M and having 1 rigid or scmirigid diaphragm. The stiffness properties used in the analysis and general mathematical modeling shall be in accord ance with Section 1630.1.2 1631.4 Description of Analysis Procedures. 1631.41 Response spectrum analysis. An clastic dynamic analysis ofa structure utilizing the peak dynamic response of all modes having a significant contribution fo total structural re~ sponse. Peak modal responses are calculated using the ordinates 6f the appropriste response spectrum curve Which cosrespond to the modal periods. Maximum modal contributions are combined ‘na statistical manner t obtain an approximate total structural re- sponse 1631.42 ‘Time-history analysis. An analysis ofthe dynamic sponse of 2 structure at each increment of time when the base is subjected to a specific ground motion time history. (CHAP. 16, OV. IV sete? 1631.5 Response Spectrum Analysis. 1631.5. Response spectrum representation and interpreta tion of results. The ground motion representation shall be accordance with Section 1631.2. The corresponding response parameters, including forces, moments and displacements, shall be denoted as Elastic Response Paramcters. Elastic Response Parameters may be reduced in accordance with Section 1631.54 1631.52 Number of modes, The requirement of Section 1631-41 that al significant modes be included may be satisfied by decaonstzating that fr the modes considered, atleast 90 percent of the participating mass of the structure is included in the calcula- tion of response for each principal horizontal direction 1631.53 Combining modes. The peak member forces, dis placements, story forces, story shears and base reactions for eaclt ‘mode shall be combined by recognized methods, When three dimensional models are used for analysis, modal interaction ef- {eels shall be considered when combining modal maxima, 1631.54 Reduction of Blastic Response Parameters for de- sign. Elastic Response Parameters may be reduced for purposes of design in xccordance with the following items, with the limita tion that in no case shall the Flastic Response Parameters be te~ dduced such that the corresponding design base shear is less chan the Blastie Response Base Shear divided by the value of R. 1, For all regular structures where the ground motion represen- tation complies with Section 1631.2, Tiem 1, Elastic Response Parameters may be reduced such thet the corresponding design ‘base shear isnot less than 90 perceat of the base shear determined in accordance with Section 1630.2. 2, Forall regular structures where the ground motion represen- tation complies with Section 1631.2, Item 2, Elastic Response Parameters may be reduced such that the corresponding design ‘pave shear isnot less than 80 percent of the base shear determined in accordance with Section 16302. 3. For all iregular structures, regardless of the ground motion representation, Elastic Response Parameters may be reduced such thatthe corresponding design base shear isnot less than. 100 per- cent of the base shear determined in accordance with Section 1630.2, ‘The corresponding reduced design seismic forces shall be used, for design in accordance with Section 1612. 1631.55 Directional effects. Directional effects for horizontal ground motion shall conform @ the requirements of Section 1630.1, The effecis of vertical ground motions on horizontal c tilevers and prestressed elements shall be considered in accord~ ‘ance with Section 1630.11. Alternately, vertical seismic response ‘may be determined by dynamic response methods; in no case shall the response used for design be less than that obtained by the static method, 5.6 Torsion, The analysis shall account for torsional ef icuding accidental torsional effects as prescribed in Sec- tion 1630.7. Where three-dimensional models are used for analysis, effets of accidental torsion shall be accounted for by ap propriate adjustments in the model suchas adjustment of mess 1o= cations, or by equivalent static procedures such es provided in Section 1630.6. 1631.5.7 Dual systems, Where the lateral forces are resisted by a doal system as defined in Section 1629.65, the combined system shall be capable of resisting the base sheat determined in accord ance with this section. The moment-tesisting fra to Section 1629.6.5, tem 2, and may be analyzed using either the procedures of Section 1630.5 or those of Section 1631.5. 247CHAP. 16, DV.IV 16318 16322 1631.6 Time-history Analysis. 1631.6. Time history, Time-history analysis shall be per- formed with pairs of eppropriate horizontal pround-motion time- history componeats that shall be selected and scaled from not less than three recorded events. Approprize time histories shall have magnitudes, fault distances and source mechanisms that are con- sistent with those that contral the design-basis carthquake (or ‘maximum capable earthquake). Where three appropriate recorded ground-motion time-history pairs are not available, appropriate Simulated ground-motion time-history pairs may be used (0 make up the total number requited. For each pair of horizontal ground= ‘iotion components, the square root of the sum of the squares (SRSS) of the 5 percentlamped site-specific spectrum of the scaled horizontal componcnis shall be constructed, The motions shall be scaled such that the average value of the SRSS spectra ‘does not fall below 1.4 times the S percent-damped spectrum of the design-basis earthquake for periods from 0.27 second to 1ST second. Each pait of time histories shall be applied simulta ‘neously to the model considering torsional effects. ‘The parameter of intozest shall be calculated for each time history analysis. If tree time-history analyses are performed, then the maximum response of the parameter of interest shall be used for design. If seven or mots time-history analyses are performed, then the average value of the response parameter of intezest may bbe used for design, 1631.62 Elastic time-history analysis. Elastic time history shall conform to Sections 1631.1, 1631.2, 1631.3, 1631.2, 1631.5.4, 1631.5.5, 1631.5.6, 16315.7 and 1631.6.1, Response parameters from elastic time-history analysis shall be denoted as Elastic Response Parameters. All elements shall be designed usiag Strength Design, Blastic Response Parameters may be scaled in accordance with Section 1631 5.4. 1631.6.3 Nonlinear time-history analysis. 1631.63.1 Nonlinear time history. Nonlinear time-history «analysis shall meet the requizements of Section 1629.10, and time histories shall be developed znd results determined in acoordance with the requirements of Section 1631.6.1. Capacities and charac teristics of nonlinear elements shall be modeled consistent with test data or substantiated analysis, considering the Importance Factor, The maximum inelastic response displacement shall not be reduced and shall comply with Section 1630.10. 1631.6.3.2 Design review. When nonlinear time-history analysis ‘is sed to justify a structural design, « design review of the lateral- Foroe-resisting system shall be performed by an independent en reecring team, including persons licensed in the appropriate fisciphnes and experienced in seismic analysis methods. ‘The Iateral-force-resisting system design review sal include, but not be Limited to, the following: 1, Reviewing the development of site-specific spectra and sground-motion time histories. 2, Reviewing the preliminary design of the lateral-force-resist- ing system. 3, Reviowing the final design ofthe lateral-force-resisting sy tem and all supporting analyses. “The engineer of record shall submit with the plans and calcula ‘tions a stufemeat by all members of the engineering team doing the review stating thai the above review has been performed. 248 11907 UNIFORM BUILDING CODE SECTION 1632 — LATERAL FORCE ON ELEMENTS: OF STRUCTURES, NONSTRUCTURAL COMPONENTS, AND EQUIPMENT SUPPORTED BY STRUCTURES: 1632.1 General, Elemeats of structures and their attachments, permanent nonstructural components and their attachments, and ‘the attachments for permanent equipment supported by a structure shall be designed to resist the total design seismic forces pre~ scribed in Section 1632.2. Attachments for floor- of roaf-monntcd equipment weighing less than 400 pounds (181 kg), and furniture ced not be designed, ‘Attachments shall include anchorages and required bracing. Friction resulting from gravity loads shall not be considered to provide resistance to seismic forces. ‘When the structural failure of the lateral-force-tesisting sy’ tems of nontigid equipment would cause a life hazard, such sy tems shall be designed to resist the seismic forees prescribed in Section 1632.2. ‘When permissible design strengths and other acceptance ria are not contained in oF referenced by this code, such criteria shall be obtained from approved national standards subject to the approval of the building official. 1632.2 Design for Total Lateral Force. The total design lateral seismic foros, , shall be detcsmined from the following formula: Fy = 40Coly Wy @2:1) Alteratively, Fy may be caked using de following foe mula: an Go fa nee ( 1+ ah) W, 622) Excpt tha Fp Shall noe es than 0.7Cul Wp and need nthe more thin Culp, (323) WHERE: fiz is the element or component attachment elevation with respect 10 grade, fs shall not be taken less than 0.0. ‘iis the structure roof elevation with respect to grade. dy is the in-structure Component Amplification Factor that var- ies from 1.010 25, ‘A valu for dp shal be selected from Table 10-0. Alternatively, this factor may be determined based on the dynamic propertics or ‘empirical data of the component and the structure that support it. ‘The value shall not be taken Tess than 1.0. Fy is the Component Response Modification Factor that shall, be faken from Table 16-0, except that X% for anchorages shall ‘equal 1,5 for shallow expansion anchor bolts, shallow chemical ‘anchors or shallow cast-in-place anchors. Shallow anchors are those with an embedment lengib-(o-diameter rato of less than 8, ‘When anchorage is constructed of nonductile materials, or by use of adhesive, Ry shall equel 1.0. ‘The design lateral forces determined using Formula (32-1) or (62-2) shail be distefbuted in proportion (othe mass distribution of the element or component. Forces determined using Formula (32-1) or (32-2) shall be used to design members and connections that iransfer these forces to the seismic-resisting systems, Members and connection design shall use tho load combinations and factors specified ia Section 1612.2 or 1612.3. The Reliabilty/Redundancy Factor, p, may be taken equal to 1.0, For applicable forces and Component Response Modification Factors in connectors for exterior panels and diaphragms, reler to Sections 1633.2.4, 1633.28 and 1633.28.1997 UNIFORM BUILDING CODE Forces shall be applied in the horizontal directions, which result in the most critical loadings for design. 1632.3 Specifying Lateral Forces. Design specifications for ‘equipment shall either specify the design lateral forces preseribed herein or reference these provisions. 1632.4 Relatiye Motion of Equipment Attachments. For equipment in Categories 1 and 2 buildings as defined in Table 16-K, the lateral-force design shall consider the effects of relative ‘motion of the points of attachment to the structure using the drift based upon Ay. 1632.5 Alternative Designs. Where an approved national standard or approved physical test data provide a basis for the ‘earthquake-resistant design of a particular type of equipment or other nonstructural component, such a standard or data may be ac- cepted as a basis for design ofthe items with the following Timita- tions: 1, These provisions shall provide minimum values for the de- sign of the anchorage and the members and connections that trans- fer the forces to tho seismic-resisting system. 2. The force, Fp, and the overturning moment used in the design of the nonstructural component shall not be less than 80 percent of the values that would be obtained using these provisions. SECTION 1633 — DETAILED SYSTEMS DESIGN REQUIREMENTS. 1633.1 General. All siructural framing systems shall comply ith the requirements of Section 1629. Only the elements of the designated seismic-force-resisting system shall be used to resist ‘design forces. The individual components shall be designed to re sist the prescribed design seismic forces acting on them. The com- ponents shall also comply with the specific requirements for the ‘material contained in Chapters 19 through 23. In addition, such framing systems and components shall comply with the detailed system design requirements contained in Section 1633, All building components in Seismic Zones 2, 3 and 4 shall be designed to resist the effects ofthe seismic forces prescribed here~ in and the effects of gravity loadings from dead, floor live and sow loads. Consideration shall be given tod by seismic loads. In Seismic Zones 2, 3 and 4, provision shall be made for the ef fects of earthquake forces acting ina direction other than the prin- cipal axes in each of the following circumstances: The structure has plan ircegulatity Type 5 as given in Table 16M. ‘The structure has plan irregularity Type 1 as given in Table 16-M for both major axes. A column of a structure forms part of two or more intersecting. Interal-force-resisting systems EXCEPTION: I the ail lool in he colina de to sexi frees acting in ther ection es than 20 pecen of te colunn axa oad cupacity, ‘The requirement that orthogonal effects be considered may be satisfied by designing such elements for 100 percent of the pre~ scribed design seismic forees in one direetion plus 30 percent of the prescribed design seismic forces in the perpendicular direc tion. The combination requizing the greater component strength shall be used for design. Alternatively, the effects of the two omtho- gonal directions may be combined on a square root of the sum of, the squares (SRSS) basis. When the SRSS method of combining, n for uplift effects caused CHAP. 16, DIV. Iv 46022 itectional effects is used, cach term computed shall be assigned the sign that will result in the most conservative result, 1633.2 Structural Framing Systems, 1633.21 General. Four types of general building framing sys- tems defined in Section 1629.6 are recognized in these provisions and shown in Table 16-N. Each type is subdivided by the types of Vertical clements used to resist lateral seismic forces. Special ‘framing requirements are given in this section and in Chapters 19) through 23, 1633.2.2 Detailing for combinations of systems. For compo- ‘ents common to different structural systems, the more restrictive detailing requirements shall be used 1633.23 Connections. Connections that resist design seismic forces shall be designed and dotailed on the drawings. 1633.24 Deformation compatibility. All structural framing elements and their connections, not required by design to be part of the lateral-foree-resisting system, shall be designed anci/or derailed to be adequate to maintsin support of design dead plus live loads when subjected to the expected deformations caused by seismie forces. PA effects on such elements shall be considered. [Expected deformations shall be determined as the greater of the ‘Maximum Inelastic Response Displacement, Ay, considering PA. ‘effects determined in accordance with Section 1630.9.2 ot the ‘deformation induced by a story drift of 0.0025 times the story height. When computing expected deformations, the stiffening effect of those elements not part of the lateral-force-resisting Sys- {em shall be neglected. For elements not part of the latcral-force-resisting system, the ‘Forces induced by the expected deformation may be considered as ultimate or factored forces. When computing the forces induced by expected deformations, the restraining effect of adjoining rigid siructares and nonstructural elements shall be considered and a sidered in the evaluation, pro lies are consistent with member and connection design and dotiling. For concrete and masonry elements that are part of the lateral- ‘orce-resisting system, the assumed flexural and shear stiffness properties shall nat exceed one hal of the gross section properties lunless a rational cracked-section analysis is performed. Addi- tional deformations that may result from foundation flexibility and digplragm deflections shall be considered. For concrete ele- ‘ments not part of the lateral-force-resisting sysiem, see Section 19217, 1633.2.4.1 Adjoining rigid elements. Moment-esistng frames and shear was may be enclosed by or adjoined by more rigid ele- ‘menis, provided ican be shown thatthe participation or failure of the more rigid elements will not impeie the verical and lateral Aoad-resisting ability of the gravity Toad and lateral-force-esisting systems. The effects of adjoining rigid elements shall be consid cred when assessing whether siucture shall be designated regu- Tar or irregular in Section 1629.5.1 1633.24.2 Exterior elements. Exterior nonbearing, nonshear wall panels or element that are atache to or encise the exterior Shall be designed to resist the forces per Forma (32-1) of (32-2) and shall accommodate movements of the structure based on Aay and temperature changes. Such elements shall be supported by means of eastinplace concrete or by mesbanical onnetions and fasteners in accordance with the following provisions: 1, Connections and panel joints sal allow for a relative move- ment between stories of aot es han two times sory dit caused 249CHAP, 16, DIV. IV T6324 163828 by wind, the calculated story drift based on Ay oF 1 mmm), whichever is greater. 2. Connections to permit movement in the plane of the panel for story drill shall be sliding connections using slotted or oversize holes, connections that permit movement by beading of steel, or other connections providing equivalent sliding and ductility ca- prcit 3, Bodies of connections shall have sufficient ductility and ro- tation eapacity to preclude fracture of the concrete or brite fail. ures af or near welds. 4, The body of the connection shall be designed for the force determined by Formula (32-2), where Rp = 3.0 and ap = 1.0, 5, All fasteners in the connecting system, such as bolts, inser, welds and dowels, shall be designed for the forces determined by Formula (32-2), where Ry = 1.0 and ay = 1.0. 6, Fasteners embedded in concrete shall he attached 10, oF hooked around, reinforcing stee} or otherwise terminated to cffec- tively transfer forces to the reinforcing steel 1633.2.5 Ties and continuity. All pars of a structure shall be interconnected and the ecrnections shall be capable of transtalt- ting the seismic force induced by the parts being connected. As a ‘minimum, any smaller portion ofthe building shall be tied to the remainder of the building with elements having atleast « strength to sesist 0.5 Cy/ times the weight of the smaller portion, ‘A positive connection for resisting a horizontal force acting pas- allel to the member shall be provided for each beam, girder or truss, This force shall not be less than 0.5 CaF tyes the dead plus live lod. 1633.2.6 Collector elements. Collector elements shall be pro- iced that are capble of transferring the seismic forces originat- ‘ng in other portions of the structure to the element providing the resistance fo those forces. Collector clements, splices and their connections to resisting clemenis shall resist the forces determined in accordance with Formula (33-1). In addition, collector elements, splices, and theit ‘connections to resisting elements shell have the design strength to resist the combined loads resulting from the special seismic load of Section 1612.4 EXCEPTION: la sactres r porous there, braced eaiey by Vight-tame wood shea walls ot igre steel nad wood siretual panel shear wal ssl, collector elements, splices and connections {Dressing elements noe only be designed to ess forces in accord fnce with Formula (331). ‘The quantity Eyy need not exceed the maximum force that can be transferred to the collector by the diaphragm and other ele~ ments of the lateral-force-resistinig system. For Allowable Stress Design, the design strongth may be determined using an allowable sess increase of 1.7 and & resistance factor, p, of 1.1. “This in- feease shall not be combined with the one-third stress increase permitted by Section 1612.3, but may be combined with the dura- tion of load inereuse permitted in Division III of Chapter 23. 1633.2.7 Concrete frames. Concrete frames required by design to be past ofthe lateral-force-resisting system shall conform to the following 1. In Seismic Zones 3 and 4 they shall be special moment- resisting frames, 2, In Seismic Zome 2 they shall, as a minimum, be intermediate ‘moment-resisting, frames, 1633.8 Anchorage of concrete or masonry walls. Concrete ‘or masonty walls shall be anchored to all floors and roots that pro- vide out-of-plane lateral support of the wall. ‘The anchorage shall 220 1997 UNIFORM BUILDING CODE provide a positive direct connection between the wall and floor or oof construction capable of resisting the larger ofthe horizontal forces specified in this section and Sections 1611.4 and 1632, In addition, in Seismic Zones 3 and 4, diaphragm to wal anchorage using embedded straps shall heve the straps alacked to of hooked ‘around the reinforcing steel or otherwise terminated to effectively transfer forces to the reinforcing sicel. Requirements for develop ing anchorage forces in diaphragms are given in Section 1633.29. Diaphragm deformation shall be considered in the design of the supported walls. 1633.2.8.1 Out-of-plane wall anchorage to flexible dia- phragms. ais section shall apply in Seismic Zones 3 and 4 ‘where flexible diaphragms, as defined in Section 1630.6, provide Jateral support for walls 1, Blements of the wall anchorage system shall be designed for the forces specified in Section 1632 where Ry = 3.0 and dy = 1.5. In Seismic Zone 4, the value of Fp sed for the design of the ele- ments of the wall anchorage system shall not be less than 420 pounds per lineal foot (6.1 KN per lineal meter) of wall substituted for. See Section 1611.4 for minimum design forces in other seismic zones. 2. When elements of the wall anchorage system are not loaded ‘concentrically or are not perpendicular to the wall, the system shall be designed to resist all components of the forces induced by the eccentricity ‘3. When plasters are present in the wall, the anchorage foree at the pilasters shall be calculated considering the additional load transferred from the wall panels (0 the pilasters. However, the minimum anchorage force ata floor or roof shall be that specified in Section 1633.2.8.1, em 1. 4,’The strength design forces for steel elements of the wall an- ‘chotage system shall be 1.4 times the forces otherwise required by this section. 5. The strength design forces for wood elements of the wall anchorage system shall be 0.85 times the force otherwise required by this section and these wood elements shall have a minimam actual net thickness of 24/2 inches (63.5 mm). 16332.9 Diaphragms. 1. The deflection inthe plane of the diaphragm shall not exceed the permissible deflection of the attached elements, Permissible 5,000, fi /sec, (1500 m/s), Ss Rock with 2,500 fi/see.< ¥, = 5,000 fh/sec, (760 mis < ¥, < 1500 m8). Se Very dense soil and soft rock with 1,200 fh/see, < Fs 5 2,500 ft/sec. (60 mis ¥, 760 mis) or with either N> Sor 5, & 2,000 pst (100 kPa), So Stiff soil with 600 sec. 7, < 1,200 iLsec. (180 mis SV, 360 m/s) orwith 15 20, nye 2 40 percent and s, < 500 psf (25 KP). Sp Soils requiring site-specific evaluation: 1. Soils vulnerable to potential failure or collapse under seis sic loading such as liquetiable soils, quick and highly sensitive clays, collapsible weakly cemented soils. 2. Peats and/or highly organie clays [A> 10 ft. (3048 mm) of peai andor highly organie elay where H = thickness of sol} 3. Very high plasticity clays [H > 25 8, (7620 mm) with PI> 75). 4. Very thick softimedium stiff clays [> 120 8. (36.580 mi). [EXCEFTION: When he sol properties sent kuowa in suicent ‘tat derine te sol pol ype Type Sp shal be wad Si Pr ble Type se need not be asumed Unies to balding aca cee sins Sol PoileType yay be eet he so eth ven tha ype Ss oxablshod by getechiel cata The criteria set forth inthe definition for Soil Profile Type Se requiring site-specific evaluation shall be considered. If tho site corresponds to tis criteria, the ste shall be clastied as Soil Pro- file Type Sp anda site-specific evaluation shall be conducted, 1636.2.1 ¥, Average shear wave velocity. v, shall be deter- ‘mined in accordance with the following formal ya 6-1) WHERE: 4 = thickness of Layer iin fet (m). ‘yy = shear wave velocity in Layer iin ./sec. (m/sec). 1636.2.2 N, average field standard penetration resistance and ‘Now, average standard penetration resistance for cohesionless soil layers. N and Noxy shall be determined in accordance with the following formula: 169826 6-2) and G63) ‘WHERI d= thicknoss of Layer ‘in foet (mm). = the otal thickness of cohesionless soil layers inthe top 100 feet (30 480 mm) Nj = the standard penetration resistance of soil layer in accordance with approved nationally recognized stand- ards, 163623 i, Average undrained shear strength. 5, shall be elermined ia accordance with the following font: de 5 = 66-4) WHERE = the total thickness (100 ~d,) of cohesive soil layers inthe top 109 fect (30 480 mm), Sj = the undrained shear strength in sccordance with approved nationally recognized standards, noi to exceed 5,000 psf (250 kPa), 1636.2.4 Soft clay profile, Sp. The existence of a total thickness of soft clay greater than 10 feet (3048 men) shall be investigated ‘where a soft clay layer is defined by sy < 500 psf (24 KPa), vue = 40 percent snd PY > 20, If these criteria are met, the sit shal be classified as Soil Profile Type 5 1696255 Soil profes Sc, Sp and Sp. Sites with Soil Pile ‘Types Sc, Sp and Sy shall be classified by using one ofthe Fol ing three methods with Ty N end, computed in all cases as speci- fied in Section 1636.2. 1, for the top 100 feet (30 480 mra) (¥ method). 2. N for the top 100 feet (30 480 mm) (W method). 3. Rexr for eohesionless soil layers (PY < 20) in te top 100 feet (30-480 mm) and average 3, for cohesive soil layers (PY > 20) in the top 100 feet (30 480 mm) (5, method). 1636.2.6 Rock profiles, 54 anid Sp. The shear wave velocity for rock, Soll Profile Type Sj, shal be ether measured onsite o esti rated by a geovechnical engineer, engineering geologist or seismologist for compeieat rock with moderate fracturing and weathering. Softer and more highly fractured and weathered rock shall either be measured on site for shear wave velocity or classi- fed as Soil Profile Type Sc. ‘The hard rock, Sol Profile Type Ss, category shall be supported by shear wave velocity measuremen cither onsite or on profiles of the same rock type in the same formation with an equal oF greater degre of weathering and facturing. Where hardrock con- ditions are known tobe continuous to a depth of 100 fest (20 480 ‘mm, surficial shear wave velocity measurements may be extrap- lated to assess 1, The rock categories, Sol Profile Types Sand 223CHAP. 16, DIV. V 1636.26 Sp, shall not be used if thete is more than 10 feet (3048 zum) of soil between the rock surfuce and the bottom of the spread footing or ‘mat foundstion, ‘The definitions presented herein shall apply to the upper 100 feet (30 430 min) ofthe site profile, Profiles containing distinetly ifferent soil Layers siall be subdivided into those layers des rated by a number from 1 to atthe bottom, where there are a total ofr distinct layers inthe upper 100 feet (30 480 mm). The symbol ‘then refers to any one of the layers between 1 and, 224 1987 UNIFORM BUILDING CODE11997 UNIFORM BUILDING CODE TABLE 16-A ‘TABLE 16-A—UNIFORM AND CONCENTRATED LOADS pero vssonoccinacr ut a a a tee co The abe sr 1 2 aes 9 2. Ascent ees and autoiams ae skoles | Feseana ars 38 an Nea tg EE on Sige er a esd rr ai a or Se acie 7 5 eae Tai ange TTT fo Da peeps eT GEE 3 7a arin on o & Lats Reatngme o Saks 1 ia gi i Hey BF Tom 3 Tis ae Fe 1s cepa Sp i a eo x 7 So ot Deis or Sina wo Baa Te Reviewing tn ganda Neon wd ‘ya ese srg wo 0 Rost Sasa ened Ra RT 16 Sk Gorm 7 ne Bien aa EOE eile 250 18 Sones ips 5 1s 250 Bsa ion etc 2 ar RS a aE 10 We gece ain ne ee Section 1607.3.3, first paragraph, for area of load application. Sha ES, ast ppp een ac pH “REET ort ae fh emerald wpe ye cay it west acts i ah ee ae re eee ee ene sa Sloe el fei i Raeee a een ane a sa nau ion er tieion ete rsd ge crt See ‘Restroom loads shall not be ess than the load for the occupancy with which they are associuied, but need not exceed S0) pounds per square foot (2.4 kN/m?),TABLE 16.8 1997 UNIFORM BUILDING CODE TABLE 16-8—SPECIAL LOADS! aT Saar aa ev aaeo oe TT Constrcion, public waxes a site (ive load) | Walkway, se Section 3308.6 1 “Cavopy, see Section 38,7 150, 2 Grandsinds, reviewing any Dleachow, and | Seas und fothoards ia0 ‘See Fostnate {oling and telescoping seating (lve toad) 3. Sings accesories lve load) Cawaite o Followspoi, pcjecion aad coat rooms 30 & Calng faming Give ad) Over sap98 20 ‘All uses excep Over Sa 10 5 Patton and iteior walls, sco Sos, TOLLS Giveleas) 5 6 Plevators and dumbwltr (cid and Hive Towa) 2 tea Toads "F_ Mechanical ad letial equipment (lead oad) Tal ons 8. Cranes (dead and ive loads) “Toa oad incoding impact oorase 125 X total tead® | O10 > tua od™ 5, Balcony lings and guarals ‘Ft clilies serving an ocoupae oad gresler shan 50 0 ‘One tia ex fen 2 Components ra 10. Vebiele barrie See Section 312235 ‘oun 7, Handrails See Footaaie Uh See Footnote 2. Straps racks ‘Over 8 fo QUE am) hh "Toa lond!? See Table 16.0 1B. Fee sprinkler sractaral suppor! pass HE eso filed pipe 18, Explosion epoaie Hazardous occupanaes ve Seaton SOT ‘he abalated loads are minim loads. Where vier vertical loads eequired by tis ede or required bythe design would cause weer sess they shale we Ponds perineal fot (14.8 for Nim). $tateral sway bracing Iouds of 24 pounds pe fot (350 Nn) parte and. 10 pounds per foo (145.9 Nin) perpendicular to seat an footboard. ‘es nt apy Io clings sa ba eilent foil acess fom below, such tht acess ot quired wie the apes above the sling, Doce not spy to cil ifthe ate areas above the ceiling are ao! provided wilh access Tis lve load need nt be considered as stig snnltneously with othe lve Teds pone typon te cling aming ori supporting uci. Shere Appetit Chater 30s beta adie, se refecnce land cies tei for addtional design regiements imgal faces ince ave forces lel heck siding on ste sto Ty ay be Sad aunt echinacea te uling ‘offic sitmited Live loads on crane support girders and ther connections shal beaker Ine scum cae rane suppor gers sad hee conection the impact factors sll be 110, ‘This apis m the ection pale othe remy rails (longi dia), The feos for forces pexpencicuae othe il 0:20 th anaveoe eaeling loads (oles, ‘xb: Hooks and ited loads), Forces ll be applied at top of al and may be ustibued stoners of male all cranes and stall bedstead Sth dos Fel ‘or lteralsttnest of the srectares supporting these a A load pe inal foot (x 14.6 fee Nan) o be applied horizon inermediat is, pane ers aed thet connectors shal bo cx ‘augles over the entire boar sf, inluding Openings and spaces eee 13 ‘ote 8. "A horizontal fa in pounds (N) applied aright angles to he vehicle rier a Bright of 18 inches (457 mm) above he park att apt digo ‘tod over a Is foot xqare (404 Setlincter-squae) ace The mounting of a ial meer of sto ibe protected tom luteus il of nr thn te 2The 250 pound (LIT EN) a member, el loads, Ror pendanopersted taveing pe square fot (2k? sped beat aight Reactons ie this osng neo ot be Sen Taoding nood aot be combined with those of Fost sorface. Te fore may be dtib- rails al be such hat the complet handrail and suppostng statute so spable of withstanding load of at east 200 pounds (690.N) ppt ay deson t ny piat a he i Tye lon sal oo ese ot cau sem rach forces of operating esuipmen,o Tack sal be deigned o that fire of one vertical ember ‘¢ bays Giecly supported by Toad ist be eppted wo eny single re sprinkler suppor pon! but wot simltaneonyt all support jis. ively wit em 9,1907 UNIFORM BUILDING CODE TABLE 18-¢ TABLES TABLE 16-6—-MINIMUM ROOF LIVE LOADS! ERD os a ar cae? 7 ia Team —[— areas [ona nom nd nom cnet | nant — oor sine 7 oar a Seems | Bactnat ‘L, Flat? or rise less than 4 wits Seti in 2 unt toraptat Gos aoe) Ach dome » 6 n 20 os Py St ethan one ght im 7 Bieta eal esa Hain Si Banta 5% tes hn {0 spe, Arch or dm with al bal os 7 mal ei theone dpb a apne Shan tes eis on 3 ie 12 uae vee in 3 vals orn UO Sos) and 2 daar ae wie ke bi 7 a ego sno ger Twas cet datcoor | __ 5 5 i i No eduction pened 5. Geos ges nd Srnho it ho 0 0 » 0 "Where now oad seu, tb oss all Be engna fovsah Tae touinnd byt iding FS. See Seon TOU For pee pape oo, se Section 1007 3 See Sections GUTS and 1607.6 fori ln edcton. Th rato ecto rn Seton 16075 Focmsa (7-1 sal be into in th ble. The maxon "auction shall ot exceed fe vale tneted in he >A ne abe fe eric Dorota tp Te eo fr ati aon te gin ‘Sesion 161 ‘is etned a Secon 300, ‘8c Soaon 16) 4 fo consented oe requeents for greenhouse wo member, ‘TABLE 16-D—MAXIMUM ALLOWABLE DEFLECTION FOR STRUCTURAL MEMBERS! {YPE OF MEMBER NMEMBGR LOADED WITH LE LOAD ONLY @) ee A aan ay US OAD ‘Roof member supposing plaster or Floor mamber 1360 wna0 Sulficient slope or canbe Shall be provided for fat ols in accordance wih Setion TOIL. Lote ln D— dead lad K.— factors determined ty Table 16. ‘1 tength of member in same units deflection. ‘TABLE 16-£—VALUE OF “K” Caio Sea enronceo covenere! sre io a5 T1655) 0 } "Seasoned Tamer stampa avg 4 mois cotet ass ia 16 pect a ne of astllaon wad we wader oy codons O ose sc as a coved 2c sls Seton 1910 fo deinons and oer eremenis. shal ete value a nlespan fr simple and comnaous sans, nd a support for cantilevers. Tme-Uependent factor T for sustained loads maybe taken egal Sve yesrsormore 20 welve months 12 se mons 1 "nce months 10TABLE 165 1997 UNIFORM BUILDING CODE TABLE 16-6 "TABLE 16-F_WIND STAGNATION PRESSURE (q,) AT STANDARD HEIGHT OF 33 FEET (10 058 mm) [Bsc wind sped opt)! Gc 1.61 fort 7 |e [mw] a0 | i] im Presa (pl) (% 0.0879 fr BNP) 126 | 164 | 28 | 36 | Mo [sa] 8s "sett Scns OR TABLE 16—COMBINED HEIGHT, EXPOSURE AND GUST FACTOR COEFFICIENT (G! a | ise eosineo seounee econnes ui te woe oar » ts rs os & ° Lis on » is ts ore a ta ih owe « ts Ls ts = tt ib tas 0 ts th iB fs tos tn a ro 2m be i » 20 ln a = 2 2 1 a at an re "Values for inlermediate heights above 15 feet (4572 nama) may be intexpolaied,1097 UNIFORM BUILDING CODE TABLE 1 TABLE 16-#—PRESSURE COEFFICIENTS (C3) TRICTURE RT TREO TERCRTON great T Pa te dee ‘agoa Namal ese etd) ‘vate ‘ied wal xin, | teowad eal Soa rath rpendicular to tidy “in peer oi | Leewded foot or at toot 0.7 outward Windwar root ise tas 21216 799 07 otwast Slope 212 Gera otesethan 2 1s) | 9 outa or 03 award Siope 512 si) wit (ov) Skim Slope» 123 coos 8 owas | Wing pl dg ar at of Sours ‘Method 2 (Projected area method) ‘On vertical projected ara ‘Strutoes 40 fet (12192 mm) or essin height | 1.3 horizoatl any dzetion Saruetares over 40 fet (12192 mam) in sighe | 1-thorizoaral any direction ‘on horizontal projected areal 07 upward 7 Blomonts and somponcnis nati wear oF ‘Wall slements ‘scoatinaity™ ‘Al sutures 1.2inward Enclosed snd unenclosed srectares 12 outward Parially enclosed strocures TSoutward Prep ale 13 fad or outa Roof elemeni™ Enclosed and wnencloved stmetues Slope < 712,58.) 13 outward lope 712 (5833) t0 12:12 (1005) 13 putware cr nward Partially enclosed stractres ‘Slope < 2:13 (16.7%) 1.Zourward Slope 212 (15.78) to 7:2 (58-36) tard ce 08 inward Slope > 7:12 (38.3%) 1 12:12 000%) outward cena 3 Elements and eappponeals in was OF ‘Wall comen? | 1S omward oe 12 inward ‘dacontuitesse Roof eaves, ake of ridges without ‘overhangs? Slope © 2:12 (167%) 23 upward Slope 2:12 (157%) 10 712 (8.345) 2 ouwaa Slope > 7:19 (58.388) 0 12:12 (100%) Ts outwacd For slopes ess han 2:12 (16.7%) “Ovethongs at roof eaves, ker o ridges, and_| 0:5 added to values above feanones F Chinneye als and sold towers ‘Square or eranguar Tiny direcion Hiexagonal or octagonal 11 any diecion Round oellptical OB any diretion 5. Opentnme ome are and rectangular : te SSOineena 40 Normal 36 “Tiengolar 32 ‘© Tower acconarine uch as ladder, condak, | Gylinddeal meribow Tyee and elevators) inches (51 tna o es in diameter ‘Over? inehes (51 mm) in ameter Fat or angular mombers 7S, agpals ighapales, anor sacs Ta any dein Ror on ary ofthe top sory of multisorypurtally enclosed structure, an 2d8ionil value of 0. wall be added to he outward Cy, The mos eriteal combination ll be used for design. For definition of pacilly enclosed srdctures, see Saction 1616 2 valos lied are fr 10-squers fot (0.93 m2 iba ares, For iba area of 100 square fet (9.29, the vale of D3 may be subtracted from Cy, except ‘Tor ares at hsortnsites with slopes les than 7 ua vera in 12 unis herzortal (SE. slope) where the vale of 8 may be subtracted from Cy, ltepolaion ‘may be wod for ibuary areas between 10 and 100 square fect (0.98 m? apd 9.29 ue). For unbuary areas greater than 1,000 squat fer (92.9), ws primary Frame vals Foe slopes greater than 12 ut vocal in 12 units horizontal (100% slope) use wall element values “Local postures shall apply over a distance frm the discon‘ of 10 fet (3088 mun) oD mes che least width ofthe structure, whichever is small Spiscoatinuites at wall corner of oot rdgos ae defined as dscoatinoous bres inthe surface where te included intric angle measures 170 degrees or less SLoad is tobe appliod on either side of dxcontnity but not simaltncously on both sides “Wind pressures sil be applied othe total normal pejectd area ofall elements on one face. The forces shal be assumed (0 at paral othe wind retin, Factor for elindrical elements ae we thirds af hese fo at o angular elemiens, 229TABLE 161 1997 UNIFORM BUILDING CODE TABLE 16 TABLE 164—SEISMIC ZONE FACTORZ Boe i Ey = 2 7 Zz 00s ous om 030 J [NOTH The ze sal be determined from the sikmi zone mop in Figure 362, ‘TABLE 16-J--SOIL PROFILE TYPES. "AVERAGE SG PROPERTIES FOR TOP Tea FEET ln a00Tan) OF BO PROFLE gore PRORLE want 7 Ye | Sanda Peers Tat Horo or | Unrnined She Fe Sonne Som Pression me Swgatlatena gals ’« | “Shewsinece st ayer en eegienen Fara ‘Se Hid Rook 5,000 300) Rak 72500 v0 5,000 et et G0 1.500) = ‘Wey Danas Sol and Sofi Rack 120010 25007 350 > 000 (G40 to 70) dw) > Sa'SoH Pratl ‘600 w 1,250 cor 1,000 9 2,000 {8010 Sea) (6010160) ae Sot Soi Froie “=a0 5 = ion a8) 60) Se ‘Soll Requiring Site-specific Fuluaion. See Section 162057 "sol Poe acs my lp wi orton 0 et GS so eS pt Le Ps tes Po i anaes ot TABLE 16-(—OCCUPANCY CATEGORY ‘mm of soft clay defined as a soll witha plasticity index, PT> 20, wae = 40 perosat ie a Bend i aeons occupancy catEcoRY OCCUPANCY OF FUNCTIONS OF STRUCTURE me Stace actor | 7 Essential llaes? ‘Group Division | Oceapancies having surge and emergony Westen Fir and police stations Garages and shcltes fr emergency vehicles and emergency art Stevtues and shelters in emespency-propaednoss coats ‘Aviation contr txress ‘Sirutures and eyuipment in eoverament communication centers and ether faces required fr emexgeacy response Standby power geacrating equipment for Category 1 fies ‘Tanks or oer sructares cotaaing housing o supporting water or other fie-suppression material or equipmens equied forthe proketvn of Category 1,2er3 seen 1s Ielties “Group I. Divisions 1,2, 6 and 7 Occupanciex and sirius therein Poasing oF spot oxi o explosive chemical ur substances Nonbuildiag structures housing, suppurag or conning quanti af tose of ‘explosive sbstaaces ta if eotained wikia a bllding, would case that ‘building tobe clasified 18a Group H, Division 1,2 on 7 Oseupaney 135 130 Tas ‘Spec eigen Severe “Group A Divisions 1,7 nd21 Occupencion Bulging housing Group E, Divisions | and'3 Ocenpancies with a capacity arcate han 300 sons Buildings housing Group B Oceupancics sod for college o ait education with capacity gteaer hun 500 students Group 1, Divisions 1209 2 Gocupaacies with $0 or more resident incapocitled pallens Dut not incladed in Category 1 Group , Division 3 Oceupunces ‘All srctures sith an ocespaney grate then $000 persons Stevetures and equipment n power generating statioos, and uther peblic uit facies notin in Caepry Citegary 2 above, nd etd for ‘continied operation 106 709 TD Std secon res All snuties housing oocopancles or having Tandions it Tied in Category 4, 20¢3 and Group U Occupancy towers 00 5 ‘Miscelianeooe steuces ‘Group U Oowipances x39 for towers 100 1.00 To "TR limiation off Tr panel conneobons i Sesto 163521 wal Be DT he Sis Soames. 2siucaral ebservationrequcinent re een ia Section 1702. Ror sachorage of machinery and equipment roused for He-safty systems, te vai off shal be aken os 1S 2301997 UNIFORM BUILDING CODE TABLE 154. TABLE 16M ‘TABLE 16-.—VERTICAL STRUCTURAL IRREGULARITIES Ty Sines ieregolarty oft story ‘Asoft ory tone im which he eral ifs les than 70 percent of ha in the ory above o ess han 152984, tem? A porcont of te average rear othe tive oes ahve Welt (nas) eogalariy Ma needy tll be csre ocx wha he effective rms fay storys more than 150 pret ofthe 162984, tem? ‘ccve tar ofan adjacent A oa ht higierthan the foo el aed not be sonired 7 Vertical geometric irregularity Vertical geometric iegtrity stl be considered to exist where te horizontal dimension ofthe aera 1629.84, tem? force-ressting system many story is more than 130 percent oft in an ajacent story. Onestry penthouses ‘ed not he considered “4 Lnrplane discontioulty in vertical lateral Torcesresirting element ‘Ant plane ff of Be lateral Toal-essting elements preter han the length of those elements 163982 5 Discontinuity in eapacity—weak story ‘wet sna ona fiche sry ecg is than 0 pret of iat nthe ny ove, The ta steath 1629.01 5s the total streagth of all sebmic-resiting elements shang the story shear forthe direction under eonsieraion ‘TABLE 16-M—PLAN STRUCTURAL IRREGULARITIES TRAEGULARITY TYPE Ano DETINTION [ReFanENeE sroTion T, Torsional irregularity —to he considered when diaphragms are not Mle ‘Torsional iresblanty shell be considered to exist when the maximam sory da, computed inclading accidental 1ea3.1, tocsion. atone etd ofthe stcton transverse tof xs more than 1-2 Ges the average ofthe story dit The 163329, em 6 {wo ends ofthe snare 2 Resntrant corners Pin sonfigoraone of sractre ad is ntera-ore-esiting stom contain rota comer, where bth 16129, jst of the ste beyond a fe-ciant comer ae ete th 1 percent of the plan dcnsen Fe tems Sand? othe given scion 7 a i “eae ee veep Saree ie ra oy ims eecuemen 4 Outotplane of Disconzincities in feceral force path, sch as out-of plane ofsets ofthe vericel element 1y092: 16h 0 inns: Biss ‘5. Nonparallel systems 7 ‘Tope a oul sing nent net palo or yt bw em aos nett | vs eas onenessTABLE 16-8 1097 UNIFORM BUILDING CODE ‘TABLE 16-NSTRUCTURAL SYSTEMS! Eg at tase snr sat wont nesnas rreoeseaeron a |g Pmees Tien alice — Traian Pana fd acne testo slal « inion He] Hl ata. | |e 5 Shae 8) eB | 8 1 HaN tela ep wl it snd ule} 8 2 Rea asa nde Pe wl | 5 Saw “|B } 2 Se ae u|B |e Trina {Te na ETS 70} ae} a Tiina Spa fnd HER caste se sla] « 4 See tt S|e] ¢€ vidio eine ss | as | aw i Stes B)E | ® bak trans fe sf] b. Concrete? 56 22 = & See a) | os + St yt ane 7 |» | w Rage tame Sa os Fae OT ee ma wu |e 5 Ste ae Bl $i ig al fame smn 8 SRE ap O18 SHS, ar eck ore wl | b Concrete? 3S 28 ea + SST amet meso se STAR) & |B | TTS i ™ a 85 28 NL, i uo) | : &) a] 8 5 eee Sih Sle) 8 2 SSS TSS ee Bg] nig Lee ee tine BS) Hu] 3 £ Sones TREES Ae & ) 8 | iw afl solo | ow Bo) | Ow 1 Ena Se Tee sf} x 2 SEINE SB] % 2 Secihsint aus gju} © 4 Concrete with concrete [MRF 42 28 = Ghee, Pench nla | ox pSSUEEIOME aie] 5 SRRSERT Si ie {TC oe Sona =p Tee eae foc Ee er a St = i see Section 1630.4 for combination of suctoral systems, Basic structural systems are defined in Section 1629.6, Prohibited in Seismic Zones 3 and 4 ‘tucludes precast concrete conforming to Section 1921.27. ‘Prohibited in Seismic Zones 3 and 4, except as permitted in Section 16342. Oedinary soment-resisting frames in Seismic Zone 1 mectng the requirements of Section 211.6 may use a 8 valve of ‘Total height of he bulling including cantilevered columns, Prohibited in Seismic Zanes 2A, 21, Sand 4 See Sexton 1633.27,+1997 UNIFORM BUILDING CODE TABLE 16-0 ‘TABLE 16-0—HORIZONTAL FORCE FACTORS, ap AND Fp ‘ELEMENTS OF STAUCTURES ANG NONSTRUCTURAL COMPONENTS AND EOUIPRENT = a FOTOTE T Hesnets of Statues {A Walls including the folowing: (1 Unbraced enie ered pgs. 2s 3a (2) er wal wrveTor cal papa Da ee rao | 1B 30 z ea Al ner sing 2 oben was io 3a Pesto eee en feed yan exenson OTE aTUCUAT TaN 25 a Gone pve rl slene a wal See a ISH v0 a0 7 Rossa Corpor A Etror and nrioromamenaton nd appendages as B- Cimnces, acks aed ansed owe sported on or POA abive ewok r ( Lateraly raced or anchored othe Sra fue af pint below thine of as 30 Lacy bce sical oe al ne wor ave Dir oonee oF iw, 30 T Signs nd loads Zs 30 1. Siarage rack cule Sona) overe RECORD mm aL a5 20 z TE Penmanen for suppor inet nd Book wack mortar @ t(D iia 10 30 3 seh Gre on Anchorage ed Tra ac Ter pond clings sod Tg Ta 1 a0 Gi Acie Rowe ayers 7 10 30 a9 Mason or cone Tina rere EDT me 70 x0 T Paton 19 30 z > [A Tanks and vessels Geld contents), incang suppon syste |__ 10 Go Teca an pontine set an asides oo anldatwokad [10 | 30 TOT TET © Ay ee eat aly Ye or condo eal anew apo as aa as 1 Anchorage of enigeny pve soppy ser and ean conmnicuons~ 73 30 7 ‘Sinnet,nchoee an pf Sytem or bey ke and el ts esessry Bir ponston of cangeney tape Salo seston ONE "ETeraoray contin wih liable o aia wail 1 30 e Ole Component A. Rigi components with date mati and athens. 10 30 1 B Rigi components with onde tral ashi i is i ‘Cele components with dil teal and atc 25 30 i 1. Fei components wik sodacile mata or wach Zs 7 i [ee Seeton 1677 for definitions of Hleble components and rigid components 2See Sections 1633.2. and 16382. fo conerere and masoary Walls and Seston 16322 For connetions fr panel connectors fee panels Applies to Seismic Zones 2, 3 and 4 only. “Ground soppored steel storage racks ray be designed using the provisions of Seeion 1634, Chapier 22, Division VI, may be used for design, povided selnic ‘design foros are egeal oor grater than thore specified m Section 15322 or 1634.2, ss appeoprise Sonly anchorage o retains noed be designed. Ceiling weight shall inchade alight stares and etc eouipment or paritions that ae laterally supposed by the cvling, For porposes of determining te esac foro, telling weight of not lx than 4p (0.19 KNIn) shal be Sed ceatings constructed of lath and plaster o gypsum bos sre ce nl atcha to suspended eed tot be analyze, provided the walls aze not over 80 fet (15 240 mm) apart ‘Light fixtures and mechanical service installed i metal suspension systems for acoustical Le and lay-n panel elings shall be independently suppeted rom the ‘sracute above as specified in UBC Standard 25-2, Parti for ase Moor systems sal b the de load of the acces lor sytem plus 25 percent othe Mor ive Toad plus 10-psf (0.48 kN) patton oe allowance Opuipment cludes, buts no ited o, boiler, chiller, bet exchangers, pumps, aihaedlng wis, cooling tones, coal panels, motors, switchgear taxs- Ginger and est equa al neo cond, ta an png wha aie mine a ecm od Te spn es ‘See Section 1632.2 for aon requremcats for deteining dp for nonig or flexibly mounted exuipeat Seismic estrains may be ome fom piping and duet supporsif all the fllowing conditions are steed: TL. aerl motion of the piping or dt Will not cause damaging isp wih other systems. 112 The piping or duct is mate of ductile material with duce connect ons. Staal mtn of the igor dot es ae cusp of ple apenances (9, snl ads) with any fer epmest piping or suc 114 L.geral motion of tho piping oF duct does ot cause loss ofsyiem Yrial suppon. 1USRod- tung support of less than 12 ieches (305 smn) in length have top connections tat casnot develop moments "Suppor members cantilevered up from the floor ae checked for stability. bets that support acelin atone evel extending from wall to wall (Continued) 238TABLE 16-0 1997 UNIFORM BUILDING CODE TABLE 16.0 FOOTNOTES TO TABLE 16-0—(Continued) "Sia resi may be omit tom oil evan sch sable a co a ut tl he llowig condi ese “2a ns ft away wil acne Geoog pet whos oe (22a mon tenn oe nt cu han tapes elena "23Kotdng sor ef ates $m eng ep const chav macs '2¢Seppnt man cneered up tom Dorcas fe an "tii dc adler cea which ee eco ling ner, sein even ile blg er sac se sabe suey este mateo hie maa of apr ms en oa aS ae : Vion alton siping geet sl be de fara eat esta fo dng iar by eer mes, Resta lao poe ‘ii vera place! ch at se vin Sr ee Sosyaed ani eqns eae ae S35 nd Sette cry ie Sen sn fee aporel ao oansb ae en ea i hal aes by Roma COS G2) or SE nan sles mane RE Srey “Stzuipmeat acral sa dried xh ht ce late este by gry tone ton ps). ‘pain anchor, wie ae ego tes ents neon hl nb aed we spe eos bas ae prea "ovement conan within icc aie ra omen and rine aoe nee ena cll ha a Sais tami et eames dpc hl ae maa ae eco le ee sheers 0 asl be sted at movement lesion treat oe rim il apy cl a, re tah pen ang allan aco anes ame axe imate: rch fees may ot Fe set Snel loud in hese resins ones pov up ett spo which ensures ta felon fea et eontvouly TABLE 16-P—A AND Oy FACTORS FOR NONBUILDING STRUCTURES. ‘STRGTORE HE. x ie 1 Wesel, including i wad pssuiznd aphores, om braced or unbraced Te 22 20 2 Gast.o-place conres ses and chimneys having walls continuous 0 the foundations 35 20 3, Distributed mass canter stucares such 25 sacs, chimneys, sls and skin-spporied vera ves 29) 20 4. Thuset towers (eesnding oF gayed),guyed tacks aad chimneys. 297 20. 5. Chntlevered colama type sutures. 2 20) 5 Cooling towers. 36 20) 7. Bins and hoppers oa braced or wae eR 29 20 Storage racks. 36 20, 9. Sign al boards 35, 20, 30, Amusoniet simctrer and notumets 2 20 1, Af othersel-sipportngstueures noi OTaawine covered. 20 20 TABLE 16-QSEISMIC COEFFICIENT C, ‘SEANEZOWE FACTOR. S01. PRORLE TYPE Ed Zaae Patz 2a ea S 2.06; 7 ng 28 033M, Ss O08 ois 020 630, ‘Oa0N, Se ‘ou org rey 0s ‘oat, S or 022 ‘28 036 oan, % oo 030, ost 6 O36, Se See FusinnieT ‘Se-specie gotocnien! investigation and dais wt response analysis sali be performed to dering isms cosficlens Yor Soll role TypeSp1907 UNIFORM BUILDING CODE TABLE 16-8 TABLE 160 ‘TABLE 16-8—SEISMIC COEFFICIENT G, TEESNS ZONE TRGTOR Sol. PROFLE TYPE zm Zao za Ea) Zea Se 0.06 uz. 016 02 03a oe 0.08 015. 020 030) 040 Se ais 025 0x2 as Os r > 018 a2 oo Ds O.tn, is 036 050 “aa ost 096% 5p 3a FoomuieT i iSite specific ecolechaialinvcSgation and dynamic a response aoalyals shal be performed wo degrnine slsmie crelicents for Soll Profle ype Se TABLE 16:S—NEAR-SOURCE FACTOR N,’ RT iA TO ROW SEE BOURGES > seme source Tre. ai hm = oi A is 12 10 5 15 Fate 7) 10 c 10 io 10 Fike Near Source Factor maybe based onthe linear iterpolation of vals for distances other than those showin the able "Te location and typeof seismic soarces tobe ws fr design shall he extablishe based on approved geotechnical data (0s reent maping active fas by he United States Gcoloicel Survey othe California Divsion of Mines and Geology). “The closest citance to sie source sal be ake asthe aiaimum distance betwozs the site and the are described bythe vertical projection ofthe source on the rfc (ace pt ofa pla) Te ee pojtion eet nas ow ef he ous eps o 10h ot at The eval of he ‘Near Source Factor cousidning ll sources shall be use for design. ‘TABLE 16-T—NEAR-SOURCE FACTOR N,+ ‘LOBEST EISTANGE TO RNOWN BESS SOURCE = seismic SouncE TPE 27m [im a ie A 20 i 16 2 To 5 16 12 10 10 ec 10 i 10. 10 "The Near Source Tacior may bo baved onthe Rncariateapolaion of vals Tor distances oir than thon sown i the table "The loeation and typeof sists source tobe weed for design sll be established based on approved geotechnical dats (e, most recent mapping of wtive fas by the United States Geological Survey ofthe Calforala Division of Miacs and Geology). 2the coset distance to seismic ute val be kes asthe minim distance bebwecn those and te area descibedby the vortcal projection of te sour on the Merle (Les surface projection of aut pane). The surface poyeton ned ot isle potions of he motos at depts of 1 amo greater The eget vale ofthe ‘Nein Factor consiering al sources shal be used for desi. TABLE 16-U-SEISMIC SOURCE TYPE! salou FEE TORE TERT sotto seis souRcE DESCRPTON _| tama ener Mgr i ‘A | Foul at ae capable of producieg Inge magnitude evens and i Mz to hme argh ais slau act B | All ts oer tian TypexA and C wen met Maes Ean that ae ot capable of prodcTng large mapnitadeeathquaice Meas {lat ioe wine tone ob sc "ube source shall bo evaluted on a site-specific basis. 2th maximum monet magne and lip rate condidons mast be satisfied concorrealy when determining ie seismic sowie ype1997 UNIFORM BUILDING CODE FIGURE 16-4 FIGURE 16-1—NINIMUM BASIC WIND SPEEDS IN NILES PER HOUR (x 1.61 for kmvh)1997 UNIFORM BUILDING CODE FIGURE 16-2 FIGURE 16-2SEISMIC ZONE MAP OF THE UNITED STATES For areas outside of the United Statos, seo Appendix Chapter 16. 2a7FIGURE 16-3, 1997 UNIFORM BUILDING CODE CONTROL FERIODS Te = Gyl2.56y p02 ‘SPECTRAL ACCELERATION (g's) 2 U ! 1 I I 1 I! ' 1 I I | i ' I! PERIOD (SECONDS) FIGURE 16-3—DESIGN RESPONSE SPECTRA1967 UNIFORM BUILDING CODE 1701 37015 Chapter 17 STRUCTURAL TESTS AND INSPECTIONS SECTION 1701 — SPECIAL INSPECTIONS A70LL General. In addition to the inspections required by Sec- tion 108, the owner or the engineer or architect of record acting as the owner's agent shall employ one or more special inspectors who shall provide inspections during construction on the types of ‘work listed under Section 1701.5. EXCEPTION: The building oficial may wave the requirement ‘or the employment of a special inspector i the contruction is of 1701.2 Special Inspector. ‘The special inspector shall be a quali- ‘ied person who shall demonstrate competence, to the satisfaction ofthe building official, for inspection of the particular type of con struction or operation requiring special inspection. 1701.3 Duties and Responsibilities of the Spectal Inspec- tor. The special inspector shall observe the work assigned for conformance tothe approved design drawings and specifications. The special inspector shall furnish inspection reports to the twuilding official, the engineer or architect of record, and other des- ignated persons. All discrepancies shall be brought tothe immed- ie atlention ofthe contractor for correction, then. if uncorrected, to the proper design authority and to the building official. ‘The special inspector shall submit a final signed report stating whether the work requiring special inspection was, to the best of the inspector's knowlege, in conformance to the approved plans and specifications and the applicable workmanship provisions of this code, 1701.4 Standards of Quality. The standards listed below fa beled a “UBC Standard’ are also listed in Chapeer 35, Pact I, and ‘are part ofthis code, The other standards listed below are recog nized standards. (See Sections 3503 and 3504.) 1, Concrete, ASTM © 94, Ready-mixed Concrete 2. Connections. Specification for Structural Joints Using ASTM A 325 or A 490 Bolts-Load and Resistance Factor Design, Research Council of Structural Connections, Section 1701.5, Item 6, Specification foe Structural Joints Using ASTM A 325 or A 490 Bolts-Allowable Stress Design, Research Council of Structural Connections, Section 1701.5, Item 6. 3. Spray-applied Hire-resistive Materials, UBC Standard 7.6, Thickness und Density Determination for Spray-applied Fire-resistive Materials 17015 ‘Types of Work, Except as provided in Section 1701.1, the types of work listed below shall he inspected by a special in spector. 1.Conerete. During the taking of test specimens and placing of reinforced concrete, See Item 12 for shotcrete. EXCEPTIONS: 1, Concrete for foundations conforming to wi mam requirments of Table 18-1 oor reap 8, Division 3 0 Group UU, Division I Ocenpases, povided the Duling ofa finds that special hazard doesnot exis. 2. Fee foundation conecets, other han cus-in-place dled ples oF (mm). 285 1 'CHAP, 48, DIV. II tete2 1816494 prestress loss duc to subgrade friction, kips (KN), section modulus with respect 10 top fiber, i. (om). Slab thickness in w ribbed (stiffened) foundation, in (om), Y= contalling service load shear fore larger of Vs oF Vay iss. (Ni). service load shear stress, psi (MPa). allowable concrete shear stress, psi (MPo). ‘maximum service load shear force in the long direction from either center lift oF edge lift swelling condition, pst, (Nim). Vs = maximum service load shear fore inthe short direction from eitber center lift or edge lit swelling condition, ips, davim). W = Joundation width (or width of design rectangle) in the direction being considered (shot of long, perpendicu- far to, 0. (0), Woe = foundation weight, Ibs. kg) vin = maximum diferent soil movement or swell, in (mm). G = slope of tangent to tendon, radians. B = relative stitness length, approximate distance from age of slab to point of maximum moment, f(r). A. = expected sorvieo load dilferential deflection of sab, in- cluding correction fo prestessing, in. (mm) (A= Ay a. Aatow = allowable differential deflection of sla, in. (mm). ‘Ay = expected service load differential deflection of slab (without deflection caused by prestressing) in, (mmm). Ay = deflection caused by presitessng, i, (mm). Uk = coefficient of fretion betwen sha ang subgrade. 18163 Foundation Investigation. A foundation investigation of th site sal be conducted in acondance with te provisions of Scetion 1804 18164 Structural Design Procedure for Slabs on Expansive Soils. 1816.4.1 General. This procedure can be used for slabs with stiffening beams (ribbed foundations) or uniform thickness foundations, To design s uniform thickness foundation, the designer must lts! design a ribbed foundation that satisfies all requirements of the design procedure for ribbed foundations. The fully eonformant ribbed foundation is then Converted to an equiv- alent uniform thickness foundation The design procedure for positensioned foundations con- structed over expansive clays should include the following steps, With the pertinent sections shown in parentheses: 1. Assemble all the known design data (Section 1816.4.2) 2. Divide un inegular foundation plan into overlapping recta gles and design each rectangular scction separately (Figure 1S-M-11), 3, Assurne atrial section for a ribbed foundation in both the long tnd short directions of the design rectangle (Section 1816-4.2). 4, Caleulate the applied service moment the section will be expected lo experience in ench direction for either the center lift or edge lift condition (Section 1816.4.7). 5, Determine the tlexural concrete stresses caused by the applied service moments and compare to the allowable flexural concrete stresses (Sections 1816.44 and 1816.47), 256 1997 UNIFORM BUILDING CODE 6, Determine the expected ciferential deflections and compare withthe allowable difecental deflections Soction 1816.4.9). 7. Calculate the applied service shear foree and shear stress in tho assume sections and compare the applied shear stress withthe allowable shear stress (Section 1816-410}. 8, Convert the ribbed foundation to an equivalent uniform thicknes foundation, if desired (Section 1816.4.1). 9. Repeat Steps 4 through 8 forthe opposite swelling condition 10, Check the desiga for the first swelling condition to nscertain iF adjustments are nccossary to compensaic lor any design changes resulting from the second design swelling condition ‘drossod in Stop 9. 11, Chock the effet of slab-subgrade frietion to ensure a resi ual compressive stress of 50 psi (0.35 MPa) atthe center ofeach design rectangle in bot directions. Adjst postlensioning fore, if necessary (Section 1816.4.6) 12, Calculate stresses due to any heavy concentrsted loads on the slab and provide special load transler details when necessary (Section 1816.4.12). 1816.42 Required design data. The soils and structural proper lies needed for design are a follows: 1. Soils prope 1.1 Allowable soi-beuring pressure, dati in pounds per square foot (newions per square mace). 4.2. Budge moistre variation distance, qin Fet (eters) 1.3. Differential soil movement, yf inches millime- (en). 1.4 Slab-subgrade friction coefficient, u. 2. Structural data and materials properties. 2.1 Slab length, L inlet (meters) both directions) 22. Perimeter loading, P in pounds per foot (newtons pet eles), 23. Average stiffening beam spacing, in feet (meters) (both directions), 24 Beam depth, in inches (millimeters). 25 Compressive strength ofthe concrete, fin pounds per square inch (MPa), 2.6 Allowable flexural ensile stress inthe concrete, f, ia pounds per square inch (MPs). 2.7 Allowable compressive stress inthe concrete, fin ‘pound per square inch (MPa). 28 Type, srade and strength ofthe prestressing steel 2.9 Prestess losses in kis per inch (KN per mis. 181643 Trial section assum 1816.43.1 Assume beam depth and spacing. An initial es imate of the depth of the stiffening beam can he obtained from solv ing either Formula (16-21) of Formula (16-22) for the beam depth ‘yielding the maximum allowable differential deflection. The pro- ‘cedure is as follows: 41. Determine the maximum distunce over which the allowable “differential deflection will ceur,L or 6B, whichever is smaller. As ‘first approximation, use B = 8 fect (2.44 m). 2, Select the allowable differential deflection Ain’ 2.1 Center lift (assume Ca = 360): 12 or 6) _ 120 or 6) Sate = Cs 300 (toa) For SI 1 inch = 25.4 mm,11997 UNIFORM BUILDING CODE 22 Rage lift (assume Cy = 720 12(L or 6B) _ 12 or 6B) Avon a Sr (16.2) For $I: 1 inch =25.4 mn Alternatively, may be selected! from Table 18--GG, which ‘presents ssmple Cg values for various types of superstructes. 3. Assume a beam spacing, S, and solve for beam depth, f 3.4L Center lift (from Formula 16-2 pine 2 Onl en(ryesn(e,) 56 380B an (16-3-1) a = (oamenenreal= a5 Fors inch = 25.4 mm, 3.2 Bdge lift (from Formula 16-21): LPS)" 9) 9) = TERA" OED pesyesteneeny) += PSBES) wt For SI: 1 inch = 25.4:mm, Select the langer from Formula (16-3-2) or (16-4-2). In the analysis procedure, the beam depth ’ must be the same for all ‘beams in both directions I different boum depths are selected for the aviual siructure (Such as a deeper edge beam), the analysis ‘Shall be based on the smallest beam depth actually used, 1816.43.2 Determine section properties. The moment of iner- tia, seetion modulus, and exost-sectional area of the slabs and beams, and eccentricity of the prestressing force shall be calcu lated for the trial beam depth determined above in accordance ‘with normal structural engineering procedures. 1BIG.AA4 Allowable stresses. ‘The following allowable stresses are recommended: 1, Allowable concrete flexural tensile stress: fom OF (16-5) For $I: f= OS VF 2 Allowable concrete flexural compressive stres: fe = 05f". ) 2. Allowable concrete Nexural compressive ares: fe = O45". (16) 3, Allowable concrete bearing stess at anchorages. BAL Atservice loud: fy = 95f'. [RE = fe 6) 3.2 Atiransfer: fig = O8f'a 5 125f'4 (16-8) 4, Allowable concrete shear stress: 1 LIF + 02% es) For Sk Ve = O14 VF + 0.f, 5. Allowable stresses in prestressing steel. 5.1 Allowable stross duc to tendon jacking force: fg OB S04 (16-10) 5.2 Allowable stross immediately after prestress trans- fer: In = OTe 1816.4.5 Prestress losses. Loss of prestress due (o friction, elas tic shortening. creep and shrinkage of the concrete, und steel relaxation shall be calculated in accordance with Section 19186. 1816.4.6 Slab-subgrade friction. The effective prestressing oreo in pasttensioned slxbs-on-ground is further reduced by the frictional resistance to movement of the slab on the subgrade dur- ing stressing as well as the frictional resistance 10 dimensional ‘changes due to concrete shrinkage, creep and temperature vara- tions. The resultant prestress force, P,., isthe difference between the effective prestress force and the losses due to subgrade fric- tiom: (6-11) P= Po - SG (6-12-41) For Si: 1 pound = 4.45 KN, ‘whore SG ean be conservatively ken as: SeEEEE Wk SG = Tau (26-12-2) For Sk: 1 pound = 4.45 KN, The largest amount of presiress oss due to slab-subgrade fri tion occurs inthe center regions ofthe slab. The greatest structural requirement for prestress force, however, is atthe location of the maximum momeat, which occurs at approximately one f-length inward from the edge of the slab. For normal construction prac tices, the value of the coefficient of friction u should be taken as 0.75 for slabs on polyethylene and 1,00 for slabs cast ditectly on a ‘sand base ‘The maximum spacing of tendons shall not exceed that which ‘would produce a minimum average ellective prestress compres- sion of 50 psi (0.35 MPa) after allowance for slab-suberade fric- tion. 1816.7 Maximum applied service moments. The maximum moment will vary, depending on the swelling mode and the slab direction being designed. For design rectangles with a ratio of long side to shor sie less than 1.1, the formulas for Mj [Formulas (16-13-1) and (16-15)] shall be used for moments in both direc- tions. Tong side o shot side less than 1-1, the fonmulas for Mj [Formulas (16-13-1) and (16-15) shall be used for moments in both dizee- tors. 1, Center it moment. 11 Long direction: M, = Alb)" + Cl 06-131) For Sk: 1 fickipsft. = 4.45 kN'mim. WHERE: = Llp enayeeg.gm| 46-13-2 Ae = FpLEN™SNM SEPM)" (1613-2) 26r(CHAP. 18, DIV. IM ‘Terear re16495, and for: O05 55 B=4C= 0 (16133) > SB (5 ) = 10 (16-124) P= 03][4 = », : ce [s eaeat [ | = 0 G65) 12 Shon retin, ForLyils = 11; co For Si 1 ftps. = 4.45 kN, Bor Lyils < Ll: My = Mi 2. age lit moment. 21 Long direction: _ @*Geniniy i : Me = ape scene? For SI: | ftps = 4.45 kN, 22 Shot direction, For [yils = 1.1: waft My = i | a i as-16) For Sk: 1 fckipyt = 445 kN'min, For Lyis < 1A: My = M, Concrete flexural siresses produced by the applied service ‘moments shall be calculated with the following formula: Pe Mis ferrets eis te Pe (46-17) For SI: pound per square iach = 0.0069 MPa, ‘The applied concrete flexural stresses Fshall not exceed fin ten- sion and fin compression 181648 Cracked section considerations, This design method limits concrete flexural tensile stresses to 6". (For Sk: 0.5 JFFo. Since the modulus of rupture of concrete is commonly taken as f., = 7.5 /f'2 (Por Sli f., = 0.625 /F"). slabs designed with this method will theoretically have. no flexural cracking. Some cracking from restraint to slab shortening is inevitable in Posttensioned slabs on ground, as iti in elevated pasitensioned conerete members. Nevertheless, the limitation of flexural tn siresses to a valuc ess than the modulus of rupture justifies the use Of the gross concrete cross section for calculating all section prop- erties, This i consisent with standard practices in elevated post tensioned concrete members. 181649 Differential deflections. Allowable and expected dif- ferential deflections may be calculated from the formulas pre sented in the following sections. 238 1997 UNIFORM BUILDING CODE 1816.49.1. Relative stiffness length. [} may be calculated as fol- lows: pesy Peet i000 Vz, If the creep modulus of elasticity of the concrete Fe is not known, it can be closely approximated by using half ef the normal ‘or eatly life concrete modulus of elasticity. LFthe modulus of elas- ‘icity ofthe lay soil Zs not known, use 1,000 psi (6.89 MPa). in Formula (16-18) is the gross moment of inertia for the entre subs ‘cross section of width W, in the appropriate direction (short or long). 1816492 Differential deflection distance. The differenti deflection may not occur over the entire length of the slab, particu- larly ifthe slab is longer than approximately 50 feet (15.24 m).. "Thos, the effective distance for determining the allowable differ. ential deflection isthe smaller ofthe two distances, Lo 6f, both expressed in feet (meters). 1816.4.9.3 Allowable differential deflection, Azuoy (in inches) (am). 1. Center lift or edge litt: (16-18) For Sk: 6 12(L or 66) be = TLS assy Forse Ag, = MEM ‘The coefficient Ca is a function of the type of superstructure ‘material and the swelling condition (center or edge lift). Sample values of C,, for both swelling conditions and vatious supersizuc- ‘ure materials are shown in Table 18-1-GG, 1816494 Expected differential deflection without prestress- ing, 4, (in inches) mm): 1. Center it = Hak 2S) =HPYN ey) 4 = a) we) For Si: Linch = 25.4 mm. 2, Fage tif a, = EPC gy) some For Si: 1 inch = 25.4 mm. 1816.49.5 Deflection caused by prestressing, Ay (in inches) (rm), Additional slab deflection is produced by prestiessing if the prestressing force at the slab edge is applied al any point other than the CGC. The deflection caused by prestzessing can be approximated with reasonable accuracy by assuming it is pro ‘duced by a concentrated moment of Pee applied atthe end of a caa- tilever with « span length of f. The deflection is: Pep? 2d am (16-22) For SE 1 inch = 25.4 mm. Ifthe tendon CGS is higher than the conerete CGC (atypical condition), dy increases the edge lift deflection and decrouses the1997 UNIFORM BUILDING CODE center lift deflection, Deflection caused by prestressing is nor- sally small and can justifiably be ignored in the design of most pposttensioned slabs on ground. 1816.4.9.6 Compare expected to allowable differential deflec- tion. Tf the expected differential deflection as calculated by either Formula (16-20) or (16-21), adjusted forthe effect of prestressing, ‘exceeds that determined from Formula (16-19) forthe appropriats swelling condition, the assumed section must be stiffened, 1816.40 Shear. 1816.4.10.1 Applied service load shear. Expected values of service shear ores in kips per foot (KN per meter) of width of sisb ‘and stresses in Kips per square inch (KN per square millimeter) shall be calculated from the following formulas: 4, Cente it 1.2. Long direction shear: Vi = Aglerr™@nsey™*or0""eu3"] (16-23) For SI: 1 kipsift. = 14.59 kN/m. LL Short divection shear: ¥. = ey LOMO*AYE.W)EN"| (16-24) For Si: 1 kipsf, = 14,59 kN/m 2. Budge lift for both directions: wemeyeseryomee aS For Sk: 1 kipsft.= 1459 kNim 1816.4.10.2 Applied service load shear stress, ». Only the beams are considered in calculating the cross-sectional area resisting shear force in a ribbed slab: 1. Ribbed foundations: Vs or Vy, = Ye nhe (1626) For Si 1 pound per square inch = 0.0069 MPa 2. Uniform thickness foundations: vy ve G (16.27) For SIE 1 pound per square inch = 0.0069 MPa, 1816.4.10.3 Compare v to ve. If y exceeds ¥, shear reinforce -moat in accozdanco with ACI 318-95 shall be provided. Possible ‘alternatives to shear cinforcerent include: 1, Increasing the beam depth, 2. Increasing the beam width, 3. Increasing the number of beams (decrease the beam spacing). 1816.41 Uniform thickness conversion, Once the ribbed foundation has been designed to sais moment, shear and differ- ‘tal defletion requirements, t may be converted to an equiva. Tent uniform thickness foundation wit thickness Fi deste. To ‘convert a ribbed slab of width, W (£..) (m) and moment of inertia, én) (mm) toa unifore thickness foundation of width, W (C-) (im) and depth, H (f1.) (m), use the following formula: pe CAE 2 (16-28) (CHAP. 18, DIV, i 1 oe a= if fe For Si: Hn y iow 1816.4.12 Calculation of stress in slabs due to load-bearing partitions. The formula for the allowable tensile stress in a slab beneath a bearing partition may be derived from beam-on-elastie foundation theory. The maximum moment directly under a point load P in such a beam is: a, - 2B ey For Sis f-kipet. = 445 kNmin WHERE: o- (BP es asan For Sts 1 fk = 445 Nin vith = 1.500.000 psi (0381 ME and ke = 4 pei (OODL th = 150,00 psi (03 hem 4 pi Némm*): Le 3f Le ho p= sm) 550 asa0 therefore: Maa = HAE 2 grp0 463) For Slept. = 4,45 kN, "The formda for pid tent tn fi 2 Mane nn & - Ape (0639 or St pound pa gure neh = 4469 MPa, snd snc: 1. BA). Bae _ we _ oe b= FG) - = = 2 the pion stot i: = 6 Be 0635) For Si 1 pound por square inch = 020069 MPa. For uniform thickness foundations substitute H for ¢in Formu~ Jas (1632), (16-33) and (16-35). The value of Gy depends om the assumed value of the subgrade modulus fy. The following table iustrates the vasiaton in for different values off Tightly compacted high 235 Plastic compres so (Conipactod, ow phate sa] 70 1a ‘Sl, compecied, sleet 0 a4 salar oF sbsized Gl Ifthe allowable tensile stress is exceeded by the results of the above enalysis, a thicker slab section should be used under the Touded area, or stiffening beam should be placed directly beneath the concentrated line load. 288Tae to17 1318 ‘SECTION 1817 — APPENDIX A (A PROCEDURE FOR ESTIMATION OF THE AMOUNT OF CLIMATE CONTROLLED DIFFERENTIAL MOVEMENT OF EXPANSIVE SOILS) In general, the amount of differential movement to be expected in a given expansive soil should be based on recommendations supplied by a registered geotechnical engineer. The geotechnical ‘engineer may nse various sol testing procedures to provide a basis for these recommendations. A procedure developed in part through the PTI-sponsored research project at Texas A & M Uni- ‘versity that may be used by geotechnical engineers (in conjunc- tion with accumulated experience with local soils conditions) as an aid for estimation of expected differential movements. of expansive soils is presented in this appendix. This procedure is applicable only in those cases where site conditions have been corrected so that soil moisture conditions are controlled by the climate alone. ‘The information necessary to determine the differential move- rment using the procedure in this appendix is the type und amount ‘of clay, the depth to eonsiant oF equlibsium suction, the edge ‘moisture variation distance, the magnitude of the equilibrium suc- tion, and the Fel! moisture velocity. With this information ether known ox eainaed,diferential movements may be selected from ‘ables 18-I-A to 18-110 forthe center lift condition, or Tables AS-IIEP to 18-IIL-DD forthe edge lilt condita, Procedures for determining or estimating the necessary items of soil information areas follows 1. Select a Thorathwaite Moisture Index fom Figure 18-11-14 or 18-11-15. Alternatively, extreme annual values of the ‘Thor thwaite Index may be calculated for a given site using Thom- thovaite’s procedures. 2, Obiain an estimate ofthe edge moisture variation distance, oo | oas7 | oors | o12 | 0.138 | 0164 | 0.190 | o2is a oo | ag | om com [os | om | 38 fos: | Sih | ta O38 | o38 | Se | nas » 36 aio} am} aa0s | 9393 | 0476 | oss | ome | a7on aim | jam | G88 | Ba | RAE | Wk | OS | str » 38 Tao | ose | oem | oss | sae | tugs | tame | 1a ’ (itis eae | bee | ie | ais | TS | tes | teat | tae 7 a teense] aon oes] ange | ears | amr | gam | ome : gs [ames [aes | ith | GaSe | te | Ste | asst | O58 ua ae pao [ais toms Tua | aes | og | oes | set > oT a109 | 0213 | 0313.) o409 | oso | oso | 0678 | 0.762 53 ce fone Dase | oss Pome [oa | ose Past [as ’ “as [OBE TORE [ORS | 888 [oss | tse | AMS | test {TABLE 104 X- DIFFERENTIAL SWELL OCCURRING AT THE PERIMETER OF A SLABFOR AN Se i SenIbI RGN PREDOMINANTLY LLITE CLAY Sole (60 PERCENT CLAY) [IFFERENTIAL SWELL OnctY ae oan, ae ET Se econ |e | cower [Mest 4 cause |e a ee 3 52 ean fares | aus | ams] cose | ao | 9077 > Fe ee 34 0S nas) cosa | oor | vos | osns | ots [oss | 7 | ae | ae | | Os | oth |S | S| 1 36 aoa tone | was | eae | ease | a2e7 | ae as Tae | Rie | AaB | 038 | OS | te | ae » 38 oe aie pas Tos ase Tose oan | aaa os | Ge | O26 |] CAR | GS | 88% | cnet | ose ’ ep a ie ae a Paar | oa | | BBE | Rome [Mtoe | ake | int | Was | oa Sef ens wis ose] aa] oase ams | oe as | gee [ks | eats | take | $8 | ome | oe » 36 05 aus 10260 | oar | oass | ose | o@ss | O7T7 i 9s | Glas | B28 | ars | Base | Sine | coms | teas 38 se pam Poa] oar] roe] ae Ppa | a ; os. | bas | BRS [TES [G3 | it | is | om 7 32 0S Too4s ) ooss | 0430 | 0473 | 0214 ] 0255 | 0206 9s | Ope | BMS | ike | Gee | 8 | Gis | Ocos ob 38 a3 cme | oie [ome | oaes | ous | ose | osis as | aoe | pase (Sam | Oe | Sas | tha | 0is7 oy 75 pe Paar Tas | ogee osm | asia | 198 ’ gs [am | a [ses | Sis | [ise | ie a8‘onroRM BuiLoNG CODE apie tee 1087 TABEE ion "ABLE eh: oIFFEDENTIAL SWELL OCCURRING A THE PERIMETER OF A SLAB FOR AN db SE DIT SELLING CONDEROR NERD MMSNTEY KATTECAA SOM orencenr ca era EL ee e tan en ep San peer ear" a “SUCTION 2 25 oe CE Ttwen | OER amet an [on [on [ow [on [om | re [on Pa a vs] gu | post | sam] eas | aac | por | ome] amr gs [3a | Gees | Sake [sot | ier | sie | os | sikh a os | ae [aos T aoe) ain | gre | aie | ome [oar 3 | tom [Wem THE | RB | SRE | ah | oak | zs % ee Ce OS [Sims [Gs | SBS | a | ORS | Ges | iss | 8 3B ds—-ae | aso | ase | ass] aan | ame | ame | one Ee ee 3 a os} aie Gena Yai tat | pie waa uae BF | Roe | HOR | mae | Be | Baw [Bz | a | Oa a os] omg ae ones | aaa | ox | ona {aie | aaar OF [a GA ake | aaa | ae | as | 88s | asi 3 us| wer | aa | owe | a5 [ae oni ome) ua G5 | as | Gam | ty | Bow | Oe | Rie | 8 |S a og ae aa [tas | ae paar | am Pa | 20m OF | ae) asm | Bs | tase | SSE | a | att | cs 7 2 03 [aoe | ome) xs Dame | ua | ox | one | oa [abe | OM | ate [ORS TASER | OR | os w os ans | aa | aa | ae (aS | Ree ame on BF thes | ORS | Be | Bast | Be [BS | As |S % bs Paar [ase | om | ame base [iss | age pass [aa [BR | Rae | a | ese | as | | "ABLE JemZ-oUEFERENTIAL SWELL OCCURRING AT THE PERIMETER OFA SLABOR A Sb Ln EW CONDON PRESOMNANTY WORTMOREL OME GAY SOL (ou peneenT co) rea See WeBReNEs Tarte io epcger | cousranr |_fretaxinonty. Ss torre —| Fr atwan | OT eus |e [oe | oe [oe [oe [on [om | *y 3 i ie | gow | ama] aor pam | cing Pane] pao) aa eee % ag] woe | tom | ome | ane] east] oo | omm |aone oe [8B | tit | is | ach [ie | eose | ons | sits 3 os | gow | oom [ aor aro Tee form | or] 9am 8 | GOB | oS [ie Pe | Sar | ie | oa | es 3 bs (au [are [ame | age | na ae | eet | se SF | Roe | aise [Gas | oa | ASE [BS | A | es 3 B cz | ans | aoe | aor | aoa] cag Poem one] ome SF | sous | a | wie [sem | eae | tee | tis | oe a os) omg | gos [oom | cum ee | gas | anne) wane GS [ams | Ges | asm | cae | 0 | tik |S | 7 os) vom | or T aim [eae | eam | exe [ome | ost Ge | aoe | ie | ae |e | R595 | tks | 8G | si a Ts — aise aai-[ sas | oar | ache | Ba | cee | Oe OS | as | ae | ae | Wee | BE | OS | Toe) Te 7 a te] ane [aes | vos Paar aig Fare) ga [rm S| aaah | aoe | ese | SRe | | SR | ake |e a oe a SS | Gass | Oem | tise | 9a | 938 | 038 | tk | oe % os fam | aa [aaa Page 1 ase Tage) onme [o7e SF [ae [GSS | Ge | Se |e |r | ath | tes 275 -naeenee eee eee PP a aa ae a a eewees wwe ew eee were ee eee eee Tape seman {907 UNFORM BUILDING CODE HABEE Sas TABLE 1eabAA DIFFERENTIAL SWELL OCCURRING AT THE PERNIETER OF & SLAB FOR AN FE ae eee UNSNTLY WOMTMORLLONTE CLAY SOI. See a T ‘DIFFERENTIAL SWELL docti) te - x ee rs a (SSR Ey | — — Tarra 7 engert |—— 8) | cgupraye tetas TT | ewwem | SSO" | ech [om | ee | on [se | se | sn | rm) on . ; [ sae | pane tame [guar Pour aoe | ous | omer as | gow | pour | ous | aaie [Sais [toe | ttre | ose 7 34 Os 0.018 0.035 0.052 | 0068 ) 0.084 009 | a.113 | 0.128 os | go | ag | aoe | 90 | Sk | RRR | Os | ont 55 ne eae aoar Twat | wuss aaa Yale one | anid gs | Gow [ogee | Ones | Sai [Sam [Sa | OR | os ~ 38 Os, 0.105 0.191 264 | os29 | ose7 | asda | 0488 0.533 os | game | Ge | O38 | SHR | Gas | Oe | ORS | oa 5 32 0019 | 0037 | 0.055 0.073 | 0.090 | 0.107 oat I ga | meee | ee | aioe | 0 | Si os | wa ca-taua | one] oie | ony | ext | a3) | B28 Pon ee 38 ‘oom | Ga00 |: 03s | oaw | osm | ose | ome oom | gum | Bes | 8S | RS | Ree | O58 | Bes of tear Poss Tam Pome | ion [ag | ae i os | aa | tee [ee [Soe [te |e | ESS | tant 7 eT setae | oot Poms pone [ont | our | oar | Bas gs | aoe | Gb | ORS | SRE TSE | Bue | OBS | obs a4 05, 0.070 | aise | 0204 7 0.268 | 0330 | oan | o4s0 | 0508 os | am | aim | ame | G38 | Sa8 [oat | 888 | 8s 3 we pase boas oar | ore | oot | as | Le ee ee SABLE 1041-86 DIFFERENTIAL SWELL OCCURRING AT THE PERIMETER OFA SLAB FOR AN SE ae eeu ORINGATLY WoNTMORLLONTE CLAY SOI ee) nee a | ae 7 aaa ae ae eeetroret a i oa Ce” an | REBT Paws [on [aw [on [om | on [on [rx [ion . : see eer Pam Paps oot oe | ae | ne os | gos | gor [aoe | ase | toa | tase | Set | ots ‘ oe [aoe Taam] copy cam | ome 7 owe T 2167 ee 36 os ‘os? Joa | isa) 0203 | 0203 | oss | os | 0358 gs | aes, | us | Gms | Gan | Ome | See | Set | as T 38 OS, a137 | 0.250 | 0.346 0431 0507 0.576 0.639 0.698 ag | gems | ame | aes [RSS | OSS | Seah | Osh | ost ; 3 paar aoe Tao oo | one Tony) on | gs | das [aoe | ame [OME | OS | Sask | Sash | Sh 7m se] aces | aioe | a] ae Oa | oan [oe | Ose a ce ee a fy tage [ose | was] see T hase | ons | oa os [aim [age | aa | OG | cass [ost | oget | tase 3 ot tae ame | pie fase as | beep a ee eee : 5 Sep aoe come one) pas ome oa | ae | us [gos | OO | ABE | Sh | O28 | 8am | OST | oa 4 oz —b ype tae] aaa] vast Pog) oa | og | oes gs | aime | Sats | tam | tat | Be | Om | oie | see sa | ae aoe | oT tee ci [ase | 18 os | ge | gee [pais [ts | ie | i | 1s | tom1807 UNIFORM BUILDING CODE mate ence u TABLE SEAS, "ABLE 1941-CC_ DIFFERENTIAL SWELL COGURRING AT THE PERIMETER OF A SLAB FOR AN Sale IS STING COMSIRON I CREDOMMNANTLY MONTMORILLONITE CLAY SOL. (60 PERCENT CLAY) Sa petro. perio ‘Eage Distance Penetration \ 3 SRST Eh Sere fenton vager age ee Se came | MO arts [Ge [an [an [on | ow | on | mm ‘ 60 a a2 Os oo | o077 | aoa | oosa [ons [007s | 0.091 | o.to4 Oy [ei | wae | iss [ase 1 Soot | Sime | i | Sieh | a 3s] ws | ost T aoe aio | -onae] numa | pigs | me Se [Sa [as [time | sit | ones | aa | ak | oan 6 as yun} aie ones | ear] oat | gar | ome] aa | © | ee ee a og [aie | ose age ose | ost | oma | ove | ose | @ Pa ee ee 5 3 og | ba] aoa] om] wale | oxae | or | oa | ame | # 35 | SHS | Gok | SR | ANE | SHE | tse | 2s | os aa os [aoe | air | one | 0am ] oes | oa | ons | owe | # a ee ee 3 is] a1 | pam | ous] og | veer] cae | oom] iter | « i [oat | tae [eas | te [se | te | ak | 3 tg Togs | are | ia | dat ae | dee | ge | ane | * OF | aa | Get [ise | ah Ts PE | ae | a 7 3 os] iss | ame [oss | vam | oa | cam | ost | aoa | @ Oh | Ohm | Gs | Ga | OBR | ORs | Om | ase | Oe 3a as Tans} aa | ow | tase ] ons | ow [ome | om | @ $3 | BES | tan | aa | te | fast | a8 | oe | Os 38 og apag Posse Pome [am Piaf aa | use| ue | @ 35 | Ba | a5 | toe | | rs | ses | aa | ath | {ABLE 1641-00 DIFFERENTIAL SELL OCCURRING AT THe PERIMETER OF A SLAB FOR AN 2S le? Set ne CONDTTONIN SREBOMINANTLY MONTMORLLONITE CLAY SOT (ra pengent Su) i DIFFERENTIAL SWELL (inch) = Ee sere. ( enon a vererr | HE | cou | nin ‘artes | oa BOT | zat, Se [cso | EE |e foe foe [mm |e [on | om [my 70 3 32 Os ‘ois | 0032 | oo | anca | ao79 | aoe | o109 | 0123 | gy | Bag | See | ak [ets | alte | ets | ts | ie ae Te) es P gos | aa | ast fase Pano [ose [one | @ $5 [BS [Stee | oe | tah | Ga | tas | cas | 0 ae og] ae | gage Poze [oa | oa | om [os | oar] @ Se | aa [case | Gea | eae | Sa | O | eh | cist aR or tom tase] co | eae Pore | cee | ose) ume | # 5 | Sa | Ses | es [as [soe | see | Sat | i 5 a os) hoe ome | ous | aie | ee | air [aoe | oe | @ SS (ts | Gam | GAG [Be | GE | Ge | oat | oe | 34 os p aon | ais Tae poms | pal | peer | aa OF [ioe | as [Ses | 8 | Sash | ase | ace | aah | Ht 36 Os aio | 0367 | O531 | 0685 | a830 | 0.967 1.097 1.221 OF [ae | Gee [Oe | ON | ENS | tas |e ah | i 38 05 pam | ase2 | i262 | 1302 | 1773 | 2020 | 2247 | 2458 St | tam | He | fa | toe | ee | 8 | dee |B | 7 32 Os “oer | 02 | ois | 0284 1 0303 | 036) | oais | 0475 Fe ee [3a 05 iss | 0266 | oaea | ost7 | aa37 [| o7s4 | 0869 | 0.980 | | SF (is | Oa | OES | OS | ogee | vost | te | 8B | T 36 Os oa | 0656 | o9s1 | 1220 | 1490 | 1739 | 1975 | 2200 I \ oF sar | oo | 304 | tse | zone | 223 | Zen | 2005 | @ zpTABLE 19:ILEE ‘TABLE 18:0-GG 1997 UNIFORM BUILDING CODE ‘TABLE 10-1I-E COMPARISON OF METHODS OF DETERMINING ‘CATION PACITY EXCHANGE CAF [ssa Ca BERNE CART eT ‘Rosie boron I ‘Speroghotonata O1-0L 2h 203. 31-02 282 262 53-05 war 0 32-06 ma 28 | 73065 218. 189 l 55-08, 450, 500 pause & Lomb “Spectronie 2" ‘TABLE 184I-F COMPARISON OF CLAY MINERAL DETERMINATION METHODS [FRE [exc menioon cose EDOM CLARA son, | PERCENT Flame, ‘Cesraistion Fieme | oeelation Fame ‘Gonelation | ay Deimetion elke [MEER me [me | eben [SEM | ao [ale | Seat | te [Star | Hea Mt eet ma | me POR [oad] all | Snake | Saoaie | Seite sma [as jus [3 | 2 1 5 [tee | tas | tay | Smene | Snoie | Smoaie os | mo |asius) 1A | Ba fom] aoc | os | Smaie | snoate | _smecte “TABLE 1040-0G—SAMPLE VALUES C, TERA ~ einen oF ear ‘Wood Frame _ 2a 430, Steen Fer 30 0 ‘Brick Veneer 480. 7 960 “Concrete Masonry Units, ee 960, 1920 Prefah Roof Trussest H 7,000 2,000 "Tess that cearspon The fl engi oF width of he Foundation Trom edge ele. 281997 UNIFORM BUILDING CODE FIGURE 1840-1 6000 — : SLABREINFORCING, | 5.000 “4 4.000 - z 5 9000 at a = 2000 t NOTE: Maximum bar spacing 18nches (457 mn) 0. 1.000 ° 20 a1 02 0a os os os re FIGURE 18:1I-1—(1-C) VERSUS Asf, 279FIGURE 19:02 11987 UNIFORM BUILDING CODE FIGURE 18-013 207) | te} te 14 ie \ _ 10 = & oa 06 _ o«4 02 ° T TT T ‘ 8 2 6 20 LUNCONFINED COMPRESSIVE STRENGTH (a) KSF (x47. for KPa) FIGURE 10-I.2—UNCONFINED COMPRESSIVE STRENGTH VERSUS SieGoNSotibaTED CORRECTION COEFFICIENT 20 7 os zal _—-t toa — ° 10 2 30 ‘SLOPE % (OF NATURAL GROUND) FIGURE 16:-9-SLOPE OF NATURAL GROUND VERSUS SLOPE CORRECTION COEFFICIENT11907 UNIFORM BUILDING CODEFIGURE 1041-5 +1997 UNIFORM BUILDING CODE 19 | + -— 2 a a 6 5 20 40 50 © 70 90 100 Low FIGURE 1811-51 or 1’ VERSUS k1997 UNIFORM BUILDING CODE FIQURE 1641-6 12 FIGURE 1 1 41-8—1-€ VERSUS CANTILEVER LENGTH (fc) 28311997 UNIFORM BUILDING CODE FIGURE 1841-7 30 FEE Ee | 5 = — + 4 te e ne ae af LL. 23 : [ 7 | BH a ot 1 ° 4 2 4 6 6 FIGURE 11-7—1-C VERSUS MAXIMUM BEAM SPACING1997 UNIFORM BUILDING CODE FIGURE 18.018 a6. os 04 18 gos ‘> * cl 02 = s | Ot }—~ | st | a sess pT] fm Ze + seer peereeraueeeee“ESCEEee Tn aaeaeer eee (eC Ee FIGURE 184-6—PI VERSUS (1-C)FIGURE 18:9 +1997 UNIFORM BUILDING CODE rriet LEV. 0.00 GROUND SURFACE —___ ¥ PI30 t 3FTOIN, ELEV.30 t WT. FAGTOR, pi70 2FTOIN, FLEV.5.0 OFT ON. WT FACTOR (er ELEV. 10.0 SFT.OIN Wr FACTOR=1 aeries ene eee eee eeeeepesHty ior Ps a Heels 2 zaaeeseaasiaaee a ie Weignod P= 1670890 «55.67 FIGURE 10/II-¢—DETERMINING THE WEIGHTED PLASTICITY INDEX (P)FIGURE 1411-10 1997 UNIFORM BUILDING CODE COMBINED SLABS. SLAB? FIGURE 10/1I-10—SLAB SEGMENTS AND COMBINEDFIGURE 18-11 4997 UNIFORM BUILDING CODE. FIGURE 19411-11—DESIGN RECTANGLES FOR SLABS OF IRREGULAR SHAPEFIGURE 18-012 1997 UNIFORM BUILDING CODE FIGURE 16-1I-12—THORNTHWAITE MOISTURE INDEX DISTRIBUTION IN THE UNITED STATES41997 UNIFORM BUILDING CODE FIGURE 184-13-1 FIGURE 1841413-1—THORNTHWAITE MOISTURE INDEX DISTRIBUTION FOR TEXAS (@20-YEAR AVERAGE, 1955-1974)+1997 UNIFORM BUILDING CODE FIGURE 1640-19.2 FIGURE 1841-13-2—THOANTHWAITE MOISTURE INDEX DISTRIBUTION IN CALIFORNIAFIGURE 1841-14 1997 UNIFORM BUILDING CODE ‘CENTER LIFT EDGE MOISTURE VARIATION DISTANCE, Gp FT [x 08.8 fr). at EDGE LIFT NOTE: The oxistonce of extremely active clays has been reported. ; ‘These days may geneva larger values of edge mosture variation istance and coneaquentl larger values of vertical movement than reflected by the above curves and related tables, For this enone awa cures shoul be ved a conuncion win ‘ote specifc sols invest ‘gootectnical angers frrowisegoabie abot focal sols contions L 1 10 o +10 420 >+80 ‘THORNTHWAITE MOISTURE INDEX FIGURE 16--14APPROXIMATE RELATIONSHIP BETWEEN THORNTHWAITE INDEX AND MOISTURE VARIATION DISTANCE11997 UNIFORM BUILDING CODE FIGURE 1846-15 20 : ’ th 4 MONTMORILLONITE toe 4 8 os ae mene 1 z é L 6 ATTAPULGITE une 02/ HALLOYSITE cHLoRITE | KAQUNITE os 1 L pt 1 on 02 04 0608 10 15 30 ACTIVITY RATIO, AC FIGURE 184115 CLAY TYPE CLASSIFICATION TO CATION EXCHANGE ‘AND CLAY ACTIVITY RATIO AFTER PEARRING AND HOLTFIGURE 1840616 41997 UNIFORM BUILDING CODE SOIL SUCTION, pf “os 4 0 2 -W oO 7062 ‘THORNTHWAITE MOISTURE INDEX FIGURE 164I-16—VARIATION OF CONSTANT SOIL SUCTION WITH THORNTHWAITE INDEX11997 UNIFORM BUILDING CODE FIGURE 16-117 20. ———-;— Ea 15 ay Ro MONTMORILLONITE, WA so} 8 : : 8 E cal 4 eit INTERSTRATIFIED | a g oat g 2 | 3 5 1 nine ATAPULOTTE | oak waLovsme poseene KAOUNITE i L ! (eee on a2 oa 08 OB 10 ACTIVITY RATIO, AC ©.0A Fame potometar @ MA Enuation 26-08 Samploro FIGURE 19.1117 COMPARISON OF CLAY MINERAL DETERMINATION USING ATOMIC ABSORPTION AND CORRELATION EQUATIONS:+1997 UNIFORM BUILDING CODE Chapter 19 CONCRETE NOTE: This is a new division. Division ‘SECTION 1900 — GENERAL 1900.1 Scope. The design of concrete structures of castin-place ‘or precest construction, plain, reinforced or prestressed shall con form to the rales and principles specified in this chapter. 1900.2 General Requirements. All concrete structures shall be designed and constructed in accordance withthe requirements of Division IT and the additional requirements contained ia Section 1900.4 ofthis division. 1900.3 Design Methods. The design of concrete structures shall te in accordance with ane ofthe following methods 1900.3.1. Strength design (load and resistance factor design). The design of concrete structures using the strenuth design method shall be in accordance with the requirements of Division 1 1900.3.2. Allowable stress design. The desiga of concrete struc tures using the Allowable Stress Design Method shall be in accordance with the requirements of Division VI, Section 1926. GENERAL 1900.6 Additional Design and Construction Requirements. 1900.4.1 Anchorage. Anchorage of bolts and headed stud anchors to concrete skal he in accordance with Division TI 1900.42 Shoterete. In addition to the requirements of Division I, design and construction of shotcrete structures shall meet the requirements of Division TV. 1900.43 Reinforced gypsum concrete. Reinforced gypsum ‘concrete shall be in accordance with Division V. 1900.44 Minimum slab thickness. The minimum thickness of ‘conetete floor slabs supported directly on the ground shall not be Jess than 34/p inches (89 mm). 1900.45 Unified design provisions for reinforced and pre- stressed concrete flexural and compression members. It shall be permitted to use the alternate flexural and axial load design pro- ‘visions in accordance with Division VIL, Section 1927. 1900.4.6 Alternative lond-factor combination and strength- reduction factors It shall be permitted to use the alternative load- factor and strength-reduction factors in accordance with Division VIMi, Section 1928, 297ee oe ee ‘sor 4902 1997 UNIFORM BUILDING CODE Division It Copyright © by the Americum Conerete Institute and reproduced with their consent. All rights reserved, ‘The contenis of this division are patterned after, and in general conformity with, the provisions of Building Code Requirements for Reinforced Concrete (ACI 318-95) und commentary—ACT 318 R-95, For additional background information and research data, see the referenced American Concrete Institute (ACD publi- cation. ‘To make reference to the ACI commentary casier for users of the code, the section designations ofthis division have been made similar to those found in ACI 318, The first two digits ofa section ‘umber indicates this chapter number and the balance matches the ACT chapter and section designation wherever possible. Italics are ‘used inthis chapter to indicate where the Uniform Building Code differs substantively fom the ACI standard. ‘SECTION 1901 — SCOPE ‘The design of structures in concrete of cast-in-place or precast construction, plain, reinforced or prestressed, shall conform 10 Uke rules and principles specified in this chapter. ‘SECTION 1902 — DEFINITIONS ‘The following terms are defined for general use in this code, Spe- Cialized definitions appear in individual sections. ADMIXTURE is material other than water, aggregate, or hy- draulie cement used as an ingredient of concrete and added to con- crete before or during its mixing to modify its properties, AGGREGATE is granular material, such as sand, gravel, ‘rushed stone and iron blast-furnace slag, and when used with ‘cementing medium forms a hydraulic cement concrete or mortar. GATE, LIGHTWEIGHT, is aggregate with a dry, hr of 70 pounds per cubic foot (pet) (1120 kgim?) ar AIR-DRY WEIGHT i the unit weight ofa lightweight conerete specimen cured fr seven days with neither loss nor gain of mois- le ai 60" F 10 80°F (15.6°C 10 26.7°C) and dried for 21 days in 50 = 7 percent relative humidity at 73.4°R © 2°F (230°C LPO). ANCHORAGE in posttersioning is a device used to anchor tendons o concrete member in pretensioning, a device used to an- ‘chor tendons during hardening of concrete. BONDED TENDON is a prestressing tendon that is bonded to concrete either directly or through grouting, CEMENTITIOUS MATERIALS are materials as specified in Section 1903 which have cementing value when used in con- ‘te either by themscives, such as poriland cement, blended hy- I Gzaulic cements and expansive cement, of such materials in ‘combination with ly ash, raw or other calcined natural pozzolans, I Sica fume, or ground granulated blast-furnace slag. COLUMN is « member with « ratio of height-to-least lateral dimension of 3 or greater used primal 10 support axial eompees- sive foe. COMPOSITE CONCRETE FLEXURAL MEMBERS are conerete flexural members of preeast and cast-in-place concrete elements or both constructed in Separate placements but so inter- connected that all elements respond (0 loads as @ unit, 2-98 COMPRESSION-CONTROLLED SECTION is 4 cross section in which the net tensile strain in the extreme tension steel at nominal strength is less than or equal to the compression= controlled strain limit COMPRESSION-CONTROLLED STRAIN LIMIT is the strain at balanced strain conditions. (See Section CONCRETE is a misture of portland cement or any other hy- 8in. 208mm) _| + Ypin. (127mm) | —"oin. (127 mm) ‘except that tolerance forthe clear distance to formed soffit shall ‘be minus 17 iach (6.4 mm) and tolerance for cover shall not ex- ‘ceed mitus one third the minimum concrete cover required by the approved plans or specifications. 1907.5.2.2 Tolerance for longitudinal location of bends and ends of reinforcement shall be + 2inches (+ 51 mm) except at discon- tinuous ends of members where tolerance shall be * ¥/p inch (127 mm, 1907.53 Welded wire fabric (with wire size not greater than WS ‘or DS) used in slabs not exceeding 10 feet (3048 mm) in span shall ‘be permitted to be curved from a point neas the top of slab over the support fo point near the bottom of slab at midspan, provided such reinforcement is either continuous aver, or securely an- chored at, support 1907.54 Welding of crossing bars shall not be permitted for as- sembly of reinforcement. EXCEPTIONS: 1. Reinforcing sie! not required by design. 2. When specifically approved by the building oficial, welding of ‘erasing bars for assembly purposes tn Seismic Zones 0, 1 and 2 may De permite. provided that data are submited ro he building oficial te show thar hres no devrimental eect on the action ofthe structed ‘member ara ren of welding ofthe crossing bare 1907.6 Spacing Limits for Reinforcement. 1907.6.1. ‘The minimum clear spacing between parallel bars in a layer shall bed but not less than 1 inch (25 min). See also Section 1903.3.2, 1907.62 Where parallel reinforcement is placed in two or more ayers, bars in the upper layers shal be placed directly above bars in the boutom layer With clear distance between layers not less than, 1 inch 25mm). 1907.63 In spirally reinforced or tied reinforced compression members, clear distance between longitudinal bars shall aot be Jess than 1.5d,or less than 1/ inches (38 min). See also Section 1903.3.2, 1907.64 Clear distance limitation betwicen bars shall apply also to the clear distance between a contact lap splice and adjacent splices or bars. (CHAP. 19, DIV. 11 "1207.5 1007.72 1907.65 In walls and slabs other than concrete joist construction, primary flexural reinforcement shall not be spaced farther apart ‘than three times the wall or sla thickness, or 18 inches (457 mm). 1907.66 Bundled bars. 1907.6.6.1 Groups of parallel reinforcing bars bundled in contact to act as a unit shall be limited to four bars in one bundle. 19076.6.2. Bundled bars shall be enclosed within stirrups or ties. 1907.6.6.3 Bars lager than No. 11 shall not be bundled in bears, 1907.6.6.4 Individual bars within a bundle terminated within the span of flexural members shall terminate at cfferent points with at Teast 40d, stagger. 1907.6.6.5 Where spacing limitations and minimum concrete cover are based on bar diameter dj, @unit of bundled bars shall be treated as a single bar of a diameter derived from the equivalent total area 1907.6.7 Prestressing tendons and ducts. 1907.6.7.1 Clear distance between pretensioning tendons at each end of a member shall aot be less then 4dp for wire, or 3s for sirends, See also Section 1903.3.2. Closer vertical spacing and bundling of tondons shall be permitted in the middle portion of af span, 1907.6.7.2 Bundling of posttensioning duets shall be permitted if itis shown that concrete can be satisfactorily placed and if provi- sion is made to prevent the tendons, when tensioned, from break- ing through the duct. 1907.7 Concrete Protection for Reinforcement. 1907.7.1 Cast-in-place conerete (nonprestressed). ‘The fol- owing minimum concrete cover shall be provided for reinforee- ment! ‘nes 4. Concrete cast against and permancaly ‘exposed to earth 306) 2 Concrei exposed to east or weather: ‘No. 6 through No. 18 bar . 261) No. 5 bar, W31 or D3I wire, and smaller 1h G8 3. Concrete not exposed to weather or in contact with ground: ‘Slabs, walls, joists: No. Hand No, 18 bar - 1 G8) No. 11 bar and smalier 34,09) Beams, colamns: Primary reinforcement, es, situps, spirals 1% G8) Shells, folded plate members: "No. 6 bar aad larger 3419) No. S bar, W31 oF D3l wire, ‘and smaller ‘arn 4. Concrete ril-up panels cast against & rigid horizontal surface, such as a mere la. exposed tothe weather. ‘No, 8 and smaller» 125) No, O through No. 18 2051) 1907.7.2 Precast concrete (manufactured under plant contrat conditions). The following minimum concrete cover shall be ‘provided for reinforcement: 2107CHAP. 19, DIV. It ard ria masa Ona ere eto ae i ts No. 14.and No. 18 bar Hh 38) No. 11 bar and smaller % 9) oot meat SOTRERe hae 28 Ne Sea vas Seals and smaller 1/4 32) 2 Cont ot xpd ar oF eae SiS Sia oe No. 14 and No. 18 bar . T4432) No. Li bar and smaller © 54 (16), ‘Beams, columns: Priaary relaforcement . 44, but not less than %¥g (16) and need nol exceed Ui Ties stizups, spi 4465) ‘Shells folded piate members 'No, 6 bar and larger 54 (16) No. 5 bar, W3I of D3i wire, ‘and smaller «| Uy 5) 1907.73 Prestressed concrete, 1907.7.3.1 The following minimum concrete cover shall be pro- vvided for prestressed and nonprestressed reinforcement, ducts and fend fittings, except as provided in Sections 1907.7.3.2 and 1907733. a mao Soe ee an 300 qt teen ane Sass "Wall panels, slabs, joists... 1@5) Other members «+. -» 1, G2) 3. Content xe wena Grace rect ; sane eae 1 Primary reinforcement ... 1h (8) rae i Sha Pel la meni: one quate? ‘than ?/4 (19) 1907.73.2 For prestressed concrete members exposed fo earth, ‘weather or corrosive environments, and in which permissible ten- silesiress of Section 19184.2, Item 3, is exceeded, minimum cov- er shall be increased 50 percent, 1907.7.33 For prestressed concrete members manufactured un= der plant control conditions, minimum concrete cover for non= prestressed reinforcement shall be as required in Section 190772. 1907.74 Bundled bars. For bundled bars, minimum concrete ‘over shall be equal to the equivalent diameier of te bundle, but need not be greater than 2 inches (51 mm excxpt for concrete cist, against and permanenily exposed to earth, minimum cover shall be 3 inches (76 mm), 1907.75 Corrosive environments. In corrosive environments or other severe exposure conditions, amount of concrete protec 2108 1997 UNIFORM BUILDING CODE tion shall be suitably increased, and denseness and nonporosity of protecting concrete shall be considered, or other protection shall be provided. 1907.7.6 Future extensions. Exposed reinforcement, inserts ‘and plates intended for bonding with future extensions shall be protected from corrosion. 1907.7.7 Fire protection. When a thickness of cover for fire protection greater than the minimum concrete cover specified in Section 1907-7 is required, suci greater thickness shall be used. 1907.8 Special Reinforcement Details for Columns. 1907.8.1. Offset bars. Offset bent longitudinal bars shall con- form to the following: 1907.8.1.1 Slope of inclined portion of an offset bar with axis of ccoluana shall nat exceed 1 in 6, 1907.8.1.2 Portions of bar above and below an offset shall be par- allel to axis of column, 1907.8.1.3 Horizontal support at offset bends shall be provided by lateral ties, spials or parts of the floor construction. Horizontal support provided shall be designed to resist one and one-half times the horizontal component of the computed force in the inclined portion of an offset bar. Lateral ties or spirals, if used, shall be placed not more than 6 inches (152 mm) from points of bend, 1907.8.1.4 Offset bars shall be bent before placement in the forms. See Section 1907.3. 1907.8.1.5 Where a column face is offset 3 inches (76 ram) or ‘greater, longitudinal bars shall not be offset bent. Separate dowels, np spliced with the longitodinal bars adjacent to the offset column aces, shall be provided. Lap splices shall conform to Section 1912.17. 1907.82 Steel cores. Load transfer in structural steel cores of ‘composite compression members shall be provided by the follow- ing: 1907.8.2.1 Ends of structural steel cores shall be accurately fin- ed to bear at end-bearing splices, with positive provision for ‘alignment of one core above the other in concentric contact. 1907.8.2.2 At end-bearing splices, bearing shall be considered effective to transfer not more than 50 percent of the total compres- sive sires in the steel core 1907.8.2.3 Transfer of stress between column hase and footing shall be designed in acoordance with Section 1915.8. 1907.8.2.4 Base of structural steel section shall be designed 10 transfer the total Toad from the entire composite member to the footing; oF, the base may be designed to transfer the Toad from the steel core only, provided ample concrete section is available for transfer of the portion of the total load carried by the reinforced ‘concrete section to the footing by compression in the concrete and by reinforcement 1907.9 Connections. 1907.9. At connections of principal framing elements (such as beams and columns), enclosure shall be provided for splices of ‘continuing reinforcement und for anchorage of reinforcement ter~ ‘inating in such connections. 1907.92 Enclosure at connections may consist of external con- ‘rete of internal closed ties, spirals or stirrups. 1907.10 Lateral Reinforcement for Compression Members. 1907.10.1 Lateral weinforcement for compression members shall ‘conform to the provisions of Sections 1907.10.4 and 1907.10.511997 UNIFORM BUILDING CODE ‘and, where shear or torsion reinforcement is required, shall also conform to provisions of Section 1911. 1907.10.2 Lateral. reinforcement requirements for composite ‘conipression merabors shall conform to Section 1910.16. Lateral reinforcement requirements for prestressing tendons shall con- form to Section 1918.11, 1907.10.3 It shall be permitted to waive the lateral reinforcement requirements of Sections 1907.10, 1910.16 and 1918.11 where tests and structural analyses show adequate strength and feasibil- ity of construction, 1907.10.4 Spirals. Spiral reinforcement for compression mem- ‘bets shall conform to Section 1910.9.3 and to the following: 1907.10.4.1 Spirals shall consist of evenly spaced continuous bar cer wire of such size and so assembled as to permit handling and placing without distortion from designed dimensions. 1907.10.42 For, cast-in-place construction, size of spirals shall 1907.10.43 Clear spacing between spirals shall aot exeeed 3 in- ches (76 mm) of be less than 1 inch (25 mm). See also Section 1903.3. 1907.10.44 Anchorage of spiral reinforcement shall be provided by one ancl one-half extra turns of spiral bar or wire at each end of a spiral unit 1907.04 Splices in spiral reinforcement shall be lap splices of 48d, but aot less than 12 inches (305 mm) or welded. 1907.10.46 Spirals shall extend from top of footing or slab in any story to level of lowest horizontal reinforcement in members sup- ported above. 1907.10.4.7 Where beams or brackets do not frame into al sides ‘of Colum, ties shall extend sbove termination of spiral to bot- tom of slab or drop panel 1907.10.48 In columas with capitals, spi level at which the diameter or width of capi the cofuma, 1907.10.4.9 Spirals shall be held firmly in place and true to line. 1907.10.5 Ties. Tie reinforcement for compression members shall conform to the following: 1907.10.5.1 All nonprestressed bars shall be enclosed by lateral tics, at east No. 3 in size for longitudinal bars No. 10 or smaller, and atleast No.4 in size for Nos. 11, 14 and 18 and bundled longi tudinal bars, Deformed wire or welded wire fabric of equivalent area shall be permitted. 1907.10,5.2. Vertical spacing of tis shall not exceed 16 longitudi- nal bar diameters, 48 te bar or wite diameters, or leest dimension of the compression member, 1907.10.5.3 Ties shall be arranged such thet every corner and al- ‘erate longitudinal bar shall have lateral support provided by the ‘corner of tie with an included angle of not more than 135 degrees xl a bar shall be not father than 6 inches (152 mm) clear on cach, side along the tie from such a laterally supported bar. Where longi- tudinal bars ere located around the perimeter of a circle, «com- plete circular tie shall be permitted. 1907.10.54 Tics shall be Jocated vertically not more than one half tie spacing above the top of footing or sib in any story and shall be spaced #8 provided herein to not more than one hl tie spacing below the lowest horizontal reinforcement in members supported above. Is shall extend to 8 is two times that of (CHAP. 19, DIV. 1967.10. 907.12, 1907.10.55 Where beams or brackets frame from four directions into a column, termination of ties not more than 3 inches (76 mm) ‘below reinforcement in shallowest of such beams or brackets stall be permitted, 1907.10.56 Column tes shall have hooks as specified in Section 1907.13, 1907.11 Lateral Reinforcement for Flexural Members. 1907.LL1 Compression reinforcement in beams shall be en- closed by tics or stizrups satisfying the size and spacing limitations in Section 1907.10.5 or by welded wire fabric of equivalent area. Such ties or stirrups shall be provided throughout the distance ‘where compression reinforcement is required. 1907.11.2 Lateral ceinforcement for flexural freming members subject (o stress reversals or to torsion at supports Shall consist of closed ties, closed stirups, or spirals extending around the flext- ral reinforcement 1907.113 Closed ties rss may be formed in one pee by Cvetaping sandad stp o een books around a longitu tal bar or formed in one of two pieces lap spliced with a Class B folice (ap of 1.3 4) ov anchored in acconance with Section pias 1907.12 Shrinkage and ‘Temperature Reinforcement 1907.12.41 Reinforcement for shrinkage and tempera stresses rommal to flour reinforcement shall be provided in structural Slabs where the Hexual reinforcement extends in one detion ony 19074211 Sheickage and temperature reinforcement shall be provided in accordance ‘wilh ier, Section 1907.22 or {907123 below. 1907.12.12 Where sirinkage and fomperiture movements are Sigifeanly Yestsoed, the requtemens of Sections 1908.24 tnd 1909.27 shall be considered, 1907.122 Deformed reinforcement conforming «Section 100553 used for shrinkage and temperature reinforcement shall be provided in accordance with the following 1907.12.21 Avea of shinkage and temperature reinforcement Shall provide atleast the following aos of enforcement area to gross concrete area bt not kes thaa 0014 1. Slabs where Grade 40 or 50 deformed bars ae used 0.0020 2. Slabs where Grade 6 deformed bars or welded wire fare (Smooth or deformed) are used ons 3. Shibs where reinforcement with yield sres ceding 6,000 pi (413.7 MP) measured tts yield strain of 035 percent is used go18_x_ 60,000 For SI: 1907.12.2.2 Shrinkage and temperature reinforcement shall be spaced not farther apart than five times the slab thickness, or 18 inches (457 mm). 1907.12.2.3 At all sections where required, reinforcement for shrinkage and temperature strosses shall develop the specified yield strength f, in tension in accordance with Section 1912. 1907.12.3 Prestressing tendons conforming tw Section 1903.5.5 used for shrinkage and temperature reinforcement shall be pro- ‘vided in accordance with the following: 2109‘CHAP. 19, DIV. I yo0r231 1908.33 1907.12.3.1 Teacions shall be proportioned to provide a min mum average compressive stress of 100 psi (0.69 MPa) on gross concrete area using effective prestrss, afer losses, in accordance with Section 1918.6, 1907.12.32 Spacing of presizessed tendons shall not exceed 6 feet (1829 mm). 1907.12.3.3 When the spacing of prestressed tendons exceeds ‘54 inches (1372 mm), additional bonded shrinkage and tempera- ture reinforcement conforming with Section 1907.12.2 shall be provided between the tendons at slab edges exiending from the sla edge for a distance equal tothe tendon spacing, 1907.13 Requirements for Structural Integrity. 1907.13.1 Ia the detailing of reinforcement and connections, members of a structure shall be effectively tied together to improve integrity of the overall structure 1907.13.2 For cast-in-place construction, the following shell constitute minimum requirements: 1907.13.2.1. In joist construction, at least one bottom ba shall be continuous or shall be spliced over the support with a Class A ten sion spliee and al noncantinuous supports be terminated with a standard hook, 1907.13.22. Beams atthe perimeter of the structure shall have at least one sixth of the tensioa reinforcement required for negative ‘moment at the support and one-quarter of the positive moment reinforcement requircd at midspan made continuous around the perimeter and tied with closed stiups or stups anchored sound the negative moment reinforcement with u hook having a bend of at least 135 degrees. Stirrups need not be extended through any joints. When splices are needed, the requized continuity shall be provided with top reinforcement spliced at midspan and bottom reinforcement spliced at or near the support with Class A tension splices. 1907.13.2.3 In other than perimeter beams, when closed stirups ‘are not provided, atleast one-quarer of the positive moment rein- forcement requited at midspan shall be continuous or shall be spliced over the support with a Class A tension splice nd at non- continuous supports be terminated with a standard hook. 1907.13.24 For two-way slab construction, 1913385, see Section 1907.13.3 For precast concrete construction, tension ties shall be provided in the transverse, longitudinal, and vertical directions and around the perimeter of the structure to effectively tie ele ‘ments together. The provisions of Section 1916.5 shall apply. 1907.13.4 For lift-slab consinuction, see Sections 1913.3.8.6 and 1918.12.6, ‘SECTION 1908 — ANALYSIS AND DESIGN 1908.0 Ni Ag = area of nonprestressed tension reinforcement, square in- ches (mm?) AG = area of compression reinforcement, squire inches (om), b= width of compression face of member, inches (ram), d= distance from extreme compression fiber to centroid of, tension reinforcement, inches (mm). modulus of elasticity of concrete, pounds per square inch (MPa). See Section 1908.1. ions, 1997 UNIFORM BUILDING CODE modulus of elasticity of reinforcement, pounds per ‘square inch (MPa). Seo Sections 1908.2 and 1908.53. fs = specified compressive strength of concrete, pounds per square inch (MPa), fy = specified yield strengt of nonprestressed reinforce- ‘mont, pounds per square inch (MP). 4, = clear span fr positive moment or shear aad average of adjacent clear spans for negative moment nominal shear strength provided by concrete. unit weight of concrete, pounds per cubie foot (kg/in") factored load per unt length of beam or per unit eres of slab. Bx = factor defined in Section 1910.2.7.3 fe = net tensile strain in exteme tension stel at nominal sttengt 1b = ati of nompresiessed tension seinforcement, Auta. p= tatio of nonprestessed compression reinforcement. Agfid reinforcement ratio producing balanced sirin condi- tions, Se Section 1910.32 ‘> = suength-reduetion factor. See Section 1909.3. 1908.1, Design Methods. 1908.1.4. In design of structural concrete, members shall be pro- portioned for adequate strength in accordance with provisions of this code, using load factors and strength-reduction Factors @ spe- ified in Section 1909, 1908.12 Nonprestressed reinforced conerete members shall be permitied to be dosigmed using the provisions of Section 1926. 1908.13 Design of reinforced concrete using Section 1927 shall >be permitted 1908.2 Loading. 1908.2.1. Design provisions ofthis cade are based on the assump- tion that stractures shall be designed to resist sll applicable loads 1908.2.2 Service loudls shull be in accordance with Chapter 16 ‘with appropriate live load reductions as permitted therein. 1908.23 In design for wind and earthquake loads, integral struc~ tural parts shall be designed to resist the (otal Lateral loads 1908.24. Consideration shall be given to offects of forces due to prestressing, crane loads, vibration, impact, shrinkage, temper fure changes, creep, expansion of shrinkage-compensating con- crete and uncqual settlement of supports 1908.3 Methods of Analysis. 1908.3.1 All members of frames or continuous construction shall, be designed forthe maximum effects of factored loads as detor- sined by te theory of clastic analysis, xcopt as modified by See- tion 1908.4. I et simplify the design by using the assumptions spociied in Sections 1908.6 through 1908.9. 1908.32 Excopt for prestressed concrete, approximate methods of frame analysis may be used for buildings af usual types of com Struction, spans and story heights 1908.3.3 Asan alternte to frame analysis, the following approx- Jato moments and shes shall be permited to be used in design of continuous beams aad one-way slabs (als reinforced to resist flexural stresses in only one direction), provide: 1. There an wo or mone spans,4997 UNIFORM BUILDING CODE 2. Spans are approximately equal, with the larger of two adja ‘cent spans not greater thaa the shorier by moro than 20 percent, 3, Loads are uniformly distributed, and 4. Unit ive load does not exceed thee times unit dead Toad, and 5. Members are p Positive moment End spans. Discontinuous end unrestrained -.--.- e+ wy Discontinuous end integral with support... wyd2/14 Interior spans my he2/6 Negative moment at exterior face of first interior support ‘Two spans wil More than two Spans 6... 1606 wee Wile /10 Negative momeat at other faces of nttior supports ee wh [Negative moment a face ofall supports for: Slabs with spans not exceeding 10 feet (3048 mmm), and beams where ratio of sum of colunan stifnesses to beam sifness excoods eight at each end of the span ub [Negtive moment at interior face of exterior support for members built integrally with supports Where support i a spandtel beam wul/24 Where support is «column . ccc Maly? Shear in end members at face of First interior support LAS vl? Shear al face ofall other supports ald 19084 Redistribution of Negative Moments in Co Nonprestressed Flexural Members. uous 1908.4.1 Except wire approximate values for moments are ‘sed, it is permitted to inerease or decrease negative moments cal- culated by elastic theory at supports of continuous flewural mem- bers for any assumed loading arrangement by not more than poe 20 ( - Pe 1908.4.2 The modified negative moments shall be used for calcu lating moments at sections within the spans. 1908.43 Redistribution of negative moments shall be made only ‘when the Section, at which moment is reduced, is so designed that por pp" is not greater than 0.50 pp, where ee O85 A, fs __ 87,000 0 OE | 7 0.856, fF’. __ 600 rst; = OP 1908.44 For criteria on moment redistribution for prestressed concrete members, ee Section 1918, 1908.5. Modulus of Elasticity. 1908.5.1. Modulus of casticity for eonerete shal be permite to be taken as w233,/f% (in psi) [For SIz_ 20.043 Jf (in ‘MPA)] for vatues of w, between 90 pet and 155 pef (1440 kg/m’ ‘CHAP. 19, DIV. It 7908.5.3, 4908.92 and 2420 kg/m). For normal-weight conerete, E, shall be per- mitted to be taken as 57,000 /f", (For St: 473077). 1908.52 Modulus of elasticity Hs for nonprestressed reinforce ment shall be permitted to be taken as 29,000,000 psi (200 000 MP2). 1908.53 Modulus of elasticity Zs for prestressing tendons shall be determined by tests or supplied by the manufacturer, 1908.6 Stiffness, 1908.6.1 Use of any set of reasonable assumptions shall be per mitted for computing relative flexural and torsional stiffnesses of ‘columns, walls, floors and roof systems. The assumptions adopted shall be consistent throughout analysis. 1908.62 Effect of hauaches shall be considered both ‘mining moments and in design of members, 1908.7 Span Length. 1908.71 Span longth of members not built integrally with sup- ports shall be considered the clear span plus Gepth of member, but need not exceed distance between Centers of supports deter. 1908.7.2 In analysis of frames or continuous construction for de- termination of moments, span length shall be taken as the distance center 0 eenter of supports, 1908.73 For beams built integrally with supports, design on the basis of moments at faces of support shall be permitted. 1908.7.4 It shall be permitted to analyze solid or ribbed slabs built integrally with suppocts, with clear spans not more than 10 feet (2048 mm), as continuous slabs on knife edge supports with spans ‘equal to the clear spans of the slab and wiih of beams otherwise neglected. 1908.8 Columns. 1908.8.1 Columns shall be designed to resist the axial forces from fuctored loads on all floors or roof and the maximum mo- ‘ment from factored loads on a single adjacent span of the floor or roof under consideration. Loading condition giving the maximum ratio of moment to arial load shall also be considered 1908.82 In frames or continuous consiniction, consideration shall be given to the effect of unbalanced floor ar roof loads on both exterior and interior columas and af eccentric loading due to other causes. 1908.83 In computing gravity load moments in columns, it shall be permitted to assume far ends of columns built integrally with the structure to be fixed. 1908.84 Resistance to moments at my floor or roof level shall be proviced by distributing the moment between columns immcdi- ately above and below the given floor in proportion tothe relative column stffnesses and conditions of restraint 1908.9 Arrangement of Live Load. 1908.9.1 tis permissible to assume thet: 1, the live load is applied only to the floor or roof under eonsid= eration, and 2. the far ends of columns built integrally with the structure are considered to be fixed. of live 1908,9.2 It is permitted to assume that the arrangemer load is limited to combinations of: 1, Factored dead load on all spans with full-factored ‘on two adjacent spans, and load amt‘CHAP. 19, DIV. yo08.6.2 909.0 2. Factored dead load on all spans with full-fectored live load ‘on alternate spaas. 1908.10 Tsbeam Constructi 1908.10.1 In T-beam construction, the flange and web shall be built integrally or otherwise effectively bonded together. 1908.10.2. Width of slab effective as a'Pbeam ange shall not ex ceed one fourth the span length of the beam, and the effective overhanging slab width on each side of the web shall not exceed: 1. Fight times the slab thickness, or 2. One half the clear distance to the next web, 1908.10.3 For beams with 2 slab on one side only, the effective ‘overhanging flange width shall not exceed: 1. One twellth the span length of the beam, 2. Six times the slab thickness, or 3. One half the elear distance to the next web, 1908.10.4 Isolated beams, in which the T-shape is used to pro a flange for additional compression arca, shall have a flange thick ‘uss not less than one half the width of web and an effective flange ‘width not more thao four times the width of web, 1908.10.5 Where primary flexural reinforcement ina slab that is considered as a'P-beam Mange (excluding joist construction) is parallel to the heam, reinforcement perpendicular to the beam Shall be provided inte top of the slab in accordance with the fol= lowing: 1908.10.5.1 Transverse reinforcement shall be Jesigned to carry tho factored load on the overhanging slab width assumed to act as 2 cantilever. For isolated beams, the full width of overhangi flange shall be considered. For other T-beams, only the elfective overhanging slab width need be considered 1908.10.5.2 Transverse reinforcement shall be spaced not farther apart than five times the slab thickness or 18 inches (457 mm), 1908.11 Joist Construction, 1908.11.1 Joist construction consists of s monolithic combination ‘of regularly spaced ribs and a fop slab arranged to span in one di- rection of two orthogonal directions. 1908.11.2 Ris shall not be less than 4 inches (102 mm) in width and shall have a depth of not more than three and one-half times the minimum width of rb, 1908.11.3 Clear spacing between ribs Shall not exceed 30 inches (762 mm). 1908,11.4 Joist construction not meeting the limitations of the preceding two paragraphs shall be designed as slabs and beams, 1908.11.58 When permanent burned elay or concrete tile fillers of ‘material having a unit compressive strength at least equal (o that of the specified sirongth of concrete in the joists are used: 1908.11.51 For shear and negative-moment strength computs- tions, i shall be permitted to include the vertical shells of fillers in ‘contuet with zibs, Other portions of fillers shall not be ineluded in strength computations. 1908.11.52 Slab thickness ever permaneat fillers shall not be Jess than one twelth the clear distance botween ribs nor less than 1172 inches (38 mm). 1908.11.5.3 In one-way joists, reinforcement normal to the ribs shall he provided in the slab as required by Section 1907.12. a2 41997 UNIFORM BUILDING CODE 1908.11.6 When removable forms ot fillers not complying with Section 1908,11.5 are used: 1908.11.6.1 Slab thickness shall not be less than one twelfth the clear distance between ribs, or less than 2 inches ($1 mm), 1908.11.6.2 Reinforcement normal tothe ribs shall be provided in the slab as requited for flexure, considering load concentra- tions, if any, but not less than required by Section 1907.12. 1908.17 Where conduits or pipes as permitted by Section 1006.3 ate embedded within the slab, slab thickness shall be al least {inch (25 mm) grester than the total overall depth ofthe con duits or pipes at any point. Conduits or pipes shall not impait sig- nificantly the strength of the consiruction, 1908.11.8 For joist construction, contribution of concrete to shear strength Vis permitted © be 10 percent more than that spe~ cified in Section 1911. It shall be permitted to increase shear strength using shear reinforcement or by widening the ends of the ribs, 1908.12. Separate Floor Finish. 1908.12.1 A floor finish shall not be included as part ofa structur al member unless placed monolithically with the floor slab or de~ signed in nocordance with requirements of Section 1917. 1908.12.21 shall be permitted to consider all conctete floor fi ‘nishes may be considered as part of required cover or total thick- ness for nonstructural considerations. SECTION 1909 — STRENGTH AND SERVICEABILITY REQUIREMENTS 1909.0 Notations. Ag, = gross area of section, square inches (ma AZ = area_of compression reinforcement, square inches (nm), b= width of compression face of member, inches (sam). € = cistance from extreme compression fer to neutral axis In inches (am. D. = dead loads, or related intemal moments and forces, 4. = distance from extreme compression fer to centroid of tension reinforcement, inches (mm). = distance from extreme compression fiber to centroid of ‘compression reinforcement, inches (ram). distance from extreme tension fiber to centroid of ten sion reinforcement, inches (mm), 0.012 (430) [For Sk: > 0.012 (4~762)}. The ‘maximum spacing of the skin reinforcement shall not exceed the lesser of d/6 and 12 inches (305 mm). It shall be permitted to in- clude such reinforcement in strength computations ifa strain com- patibility analysis is made to determine stresses inthe Individual bars or wires, The total area of longitudinal skin reinforcement in bot faces need not exceed one half of tie required flexural tensile reinforcement 1910.7 Deep Flexural Members. 1910,7.1 Flexural members with overall depth-to-clear-span re ‘ios greater than two fifths for continuous spans, or four fifths for imple spans, shall be desigacd as deep flexural members, taking into account nonlinear distribution of strain and lateral buckling. 1910.7.2 Shear strongth of deep flexural members shall be in ac- cordance with Section 1911.8. 1910.7.3 Minimum flexural tension reinforcement shall conform, to Section 19105, 1910.74 Minimum horizontal and vertical reinforcement in the side faces of deep flexural members shall be the greater of the re- quirements of Sections 1911.88 and 1911.89 or Sections 1914.32 and 191433, 28 1097 UNIFORM BUILDING CODE 1910.8 Design Dimensions for Compression Members. 1910.8.1 Ssolated compression member with multiple sj vals, Outer limits of the effective cross section of 4 compression ‘member with Iwo of more interlocking spirals shall be taken at a distance outside the extreme limits of the spirals equal t the mini= ‘mum concrete cover required by Section 1907.7, 1910.82 Compression member built monolithically with wall, Outer limits ofthe effective eross section of a spirally rin- {orced or tied einzarced compression member built monotithical- ly with a conerete wall or pier shal be taken not greater than 1p ints (38 mm outside the spiral or te reinforcement. 1910.83 As an alternate to using the fll gross area for design of a ‘compressive member with a square, octagonal or other shaped ‘oss section, it shall be permitted to use e circular section with a ‘diameter equal to the least lateral dimension of the actual shape. 1910.84 Limits of section, For a compression member with a ‘ross section larger thaa requiced by considerations of loading, it Shall be permitted to base the minimam reinforcement and design. sirength on reduced effective area Ay ot less than one bal the total area. This provision shall not apply in Seismic Zones 3 and 4 1910.9 Limits for Reinforcement of Compression Members, 1910.9.1 Area of longitudinal reinforcement for noncomposite compression members shall not be less than 0.01 or more then 0,08 times gross area Ay of section. 1910.92 Minimum number of longitudinal bars in compression ‘members shall be four for bars within rectangular or circular ties, ‘throc for bars within triangular ties, and six for bars enclosed by spirals conforming to the jollowing ratio: 1910.93 Ratio of spiral reinforcenient p, shall not be less than the p= oas(¥2— ah where f is the specified yield strength of spiral reinforcement but not mote than 60,000 psi (413.7 MPa) 1910.10 Slenderness Effects in Compression Members. 1910.10.1 Except as allowed in Section 1910.10.2, the design of ‘compression members, restraining beams and other supporting members shall be based on the factored forees and moments from 1 second order analysis considering materials noalineatity and ‘cracking, as well as the effects of member curvature and lateral dif, duration of loads, shrinkage and creep, and interaction with the supporting foundation. The dimensions of each member cross section sed in the analysis shall be within 10 percent of the dimensions of the members shown on the design drawings and the fnalysis shall be repeated. The analysis procedure shall have been shown to result in prediction of strength in substantial agreement with the results of comprehensive tests of columns in statically indeterminate reinforced concrote structures. 1910.10.2 As an alternate ofthe procedure preseribed in Section 1910.10-1, it shall be permitted to base the design of compression, members, restraining beams, and other supporting members on ‘axial forces and momeats from the analyses described in Section 1910.11. 1910.11 Magnified Moments-—General 910.L1.1 The factored axial forees, Py, the factored moments, 1M; and Mz, at the ends of the colurha tnd, where required, the relative laterel story deflections, A,, shall be computed using an clastic first-order frame analysis with the section properties de~ (10-6)1997 UNIFORM BUILDING CODE termined taking into account the influence of axial loads, the pres- ence of cracked! regions along th: length of the member and effects (of duration of loads. Alternatively, it shall be permitted to use the following properties for the memhers in the structure: 1. Modulus of elasticit 2. Moment of inertia: K. from Section 1908.5.1, Beams 0135 Je Calumns 0.70 Ig Walls—Uneracked 0.70 ly —Cracked 035% Flat plates and fet slabs 0.25 Ig 3. Arca LOAy ‘Tae moments of inertia shall be divided by (1 +) when: 1. sustained lateral loads act, o for 2. stability checks made in accordance with Seetion 1910.13.6 1910.11.2 It shall be permitted to take the radius of gyration, 7, ‘equal to 0.30 times the overall dimension ofthe direction stabilily is being considered for rectangular compression members and (0.25 tigses the diameter for circular compression members. For other shapes, it shall be permitted to compute the radius of uyra- tion for the gross conerete section. {910.113 Unsupported length of compression members, 1910.11.3.1 ‘The unsupported length , of a compression member shall be taken as the clear distanco between floor slabs, beams o other members capable of providing lateral support in the direc tioa being considered, 1910.11.32 Where column capitals or haunches are present, the ‘unsupported length shall be measured to the Tower extremity of the capital or haunch in the plane considered, 1910.11.4 Columns and stories in structures shall be designated, fas nonsway or sway columns or stories. The design of columns in rnonsway frames oF stares shall be based on Section 1910,12. The design of colunans in sway frames or stories shall be based on Sec- tion 1910.13. 1910.11.41 It shall be permitted to assume u coluran in 2 struc ture is nonsway if the inerease in column end moments due to second-order effects does not exceed 5 percent of the first-order end moments. 1910.11.42 It also shall be permitted to assume a story within a structure is nonsway if: DPA Q = A7~ istessthin or equal 190.95, (40-7) where BP, and Yate the total vertical foad and the story shear, respectively, inthe story in question and is the first-order rela: tive delletion between the top and bottom ofthat tory due Vu 1910.11.8 Where an individual compression member in the frame has a slenderness, kiy/r, of more than 100, Section 1910.10.1 shall be used to compute the forces and moments inthe frame. 1910.11.6 For compression members subject to bending about both principal axes, the moment about cach axis shall be magni- fied separately based on the conditions of restraint coztesponding to that axis, 1910.12. Magnified Moments—Nonsway Frames. 1910.12.1 For compression members in nonsway frames, the cffective length factor k shall be taken as 1.0, unless analysis shows that « lower value is justified. The caleulation of k shall be based on the E and / values used in Section 1910.11... 1910.12.2 In consway frames it shall be permitted to ignore slen- dozness effect for compression members Which satistY: Bee ua wanuy (10-8) ‘where M; Mz is not taken Tess than ~D.S. The term My/Mz is posi- tive if the column is bent in single curvature. 1910.12.3 Compression members shull be designed for the fac ‘ored axial load, Py, and the moment amplified for the effects of ‘member curvature, Mz, as follows: Me = by My (10-9) WHERE: (10-10) (0-11) ET shall be taken as = @2Ed, + Fl ay = Oe (1012) or 0.80 Ie a= SEE (103) 1910.12.3.1 For members without transverse Joads between sup- ports, Gy shall be taken as Mi c= 06 + 0a a 04 (0-4 ‘where Mj/M is positive ifthe column is bent in single curvature. For members with transverse loads between supports, Cy shall be taken as 1.9. 1910.12.3.2 The factored moment Mp in Formula (10-9) shall not ‘ve taken less than Mai = P, (06 + 0.03%) (10-15) about each axis sepacately, where 0.6 and ft aro in inches. For members for which Bf iy exceeds Mp, the value of Cy, in For- saul (10-14) shall either be taken equal to 1.0, or shall be based on the rato of the computed end moments M and Mp. 1910.13 Magnified Moments—Sway Frames. 1910.13.1 For compression members not braced against side sway, the effective length factor k shall be determined using E and ith Section 1910.11.1 and shall be greater 1910.13.2 For compression members not braced against side sway, effects of slenderness may be neglected when Riy/r is less than 22, 1910.13.3 The moments My and My at the ends of an individual ‘compression member shall be taken as My = My + bMy (10-16) an9CHAP, 19, DIV. It ioroi33 yo10.t87 My = May + 8M, 0-17) where bf, and BjMyy shall be computed according to Section 1910.3.4. 1910.13.4 Calculation of 8,44, 1910.13.4.1. The magnified sway moments 6,§, shall be taken as the column ead momeats calculated using a second-order elastic analysis based on the member stifinesses given in Section 1S10.11.1. 1910.13.42. Alternatively it shall be penmitted to calculate 8.4, (10-18) 18, calculated in this way exceeds 1.5, 6M, shall be caleuated using Seotion 1910.13.41 or 1910.13.43. 1910.13.43 Alternatively, it shall be permitted to cateulate the ‘magnified sway moment yA, 28. (40-19) ‘where ZP,, i the summation fora the vertical Toads ina story and {EP isthe summation forall sway resisting columas in a story, Pe js calculated using Formula (10-11) using & from Section 1910,13.1 and £1 from Formula (10-12) or (10-13), 1910.13. If an individual compression member has (40-20) Vie it shall be designed forthe factored axial load, Py, am the moment, ‘Me, calculated using Section 1910.12.3 in which My and Mp are ‘computed in accordance with Section 1910.13.3, iy as defined for the load combination under consideration and & as defined in Sec- tion 1910.12. 1910.13.6 In addition to load cases involving lateral louds, the strength and stability of the structure as a whole under factored gravity loads shall be considered. 1. When 8M; is compute fom Section 1910.13.41, the ratio of second-order Inter deflections first-order lateral efletions for 1-4 dead load and 1.7 live load pls lateral load applied tothe structuze shall not exceed 2.5. 2, When 85M is computed according to Section 1910.13.4.2, the value of G computed using ZP, for 14 dead oad plus 1.7 ive Joa shall not exceed 0.60, 3. When &M@, is eomputed from Section 1910.13.43, 8 com- puted using 2P, and 2P, corresponding to the factored deed and live loads shall be positive and Shall not exceed 2.5 In cases 1, 2 and 3 above fly shall be taken asthe ratio of the smaimum factored sustained exial loa tothe total fuetored axial Toad. 1910.13.7 In sway frames, flexural members shall be designed for the total magnified end moments of the compression members atthe joint. 1910.14 Axially Loaded Members Supporting Slab Sys tem, Axially loaded members supporting slab system included within the scope of Section 1913.1 shall be designed as provided in Section 1910 and in accordance with the additional require rents of Section 1913, 2120 1997 UNIFORM BUILDING CODE 1910.15 ‘Transmission of Column Loads through Floor Sys tem, When the specified compressive strength of concrete in a ‘column is greater than 1 times that specified for a floor system, transmission of load through the floor system shall be provided by ‘one of the following: 1910,18.1 Concrete of strength specified for the column shall be placed in the floor a the column location, Top surface of the col~ ‘oma concrete shall extend 2 feet (610 mm) into the slab from face fof column, Column concrete shall be well integrated with floor conereie, and shall be placed in accordance with Sections 1906.45 and 1906.46. 1910.15.2. Strength of « column through a floor system shall be ‘based on the lower value of concrete streagth with vertieal dowels and spirals as required, 1910.15.3 For columns laterally supported on four sides by beats of approximatcly equal depth oF by slabs, strength of the column may be based on aa assumed concrete strength in the col~ ‘umm joint equal to 75 percent of column concrete strength plus 35 peroont of floor conerete strength. 1910.16 Composite Compression Members. 1910.16.1 Composite compression members shall include all such ‘members reliforced longitudinally with structural steel shapes, pipe or tubing with or without longitudinal bars. 1910.16.2 Strength of a composite member shall be computed for the same limiting conditions applicable to ordinary reinforced concrete members, 1910.16.3 Any axial load strength assigned to concrete of a com- posite member shall be transferred to the concrete by members or brackets in direct bearing on the composite member eoneret. 1910.164 All axial load strength not assigned to concrete of a ‘composite member shall be developed by direct connection tothe structural steel shape, pipe or tube, 1910.16. For evaluation of slendemess effect, radius of gyra- tion of a composite section shall not be greater than the value giv enby: (qo-21) and, a an alemative to more accurate clevlation, in Formula (Go-it shall be taken ether a6 Formula (10-12) or bis a 1910.166 Structaralseel-encased concrete core 1910.16.6.1 Fora composite member with concrete core encssed by structural steel, thickness ofthe steel eneascinent shall not be fess than Ele + EL (10-22) i » Ve for each fae of width B 3E {i te for etree seins of diameter 1910.16.6.2. Longitudinal bars located within the encased con crete core shall be permitted to be used in computing Ay and f, 1910.6.7 Spiral reinforcement around structural steel ‘core, A composite member with spirully reinforced concrete around a structural steel core shall conform to the following:11997 UNIFORM BUILDING CODE 1910.16.71. Specified compressive strength of concrete’: shall rot be less than 2,500 psi (17.24 MPa). 1910.16,7.2 Design yicld strength of structural stzel core shall be the specified minimum yield strength for grade of structural steel used but not to exceed 50,000 psi (344.7 MPa). 1910.6.7.3 Spiral reinforcement shell conform to Section 1910.93. 1910.16.7.4 Longitudinal bars located within the spiral shall not be less than 0.01 ar more than 0.08 times net area of concrete sec- tion, 1910.16.7.5 Longitudinal bars located within the spiral shall be permitted to be used in computing A, and I. 1910.16.8 Tie reinforcement around structural steel core, A ‘composite member with laterally tied concrete atound a structural steel core shall conform to the following: 1910.16.8.1 Specified compressive strength of concrete /: shall ot be Tess than 2,500 psi (17.24 MP2). 1910.16.8.2 Design yield strength of structural stool core shall be the specified minimum yield strength for grade of structural stel used but not 10 exceed 50,000 psi (344.7 MPa). 1910.16.83 Lateral ties shall extend completely around the structural steel core. 1910.16.84 Lateral tes shall have a diameter not Tess then gg times the greatest side dimension of composite member, ex- | opt that tes shal nt be smaller than No. 3 and are not required to ‘be larger than No, 5, Welded wire fabric of equivalent area shall be permitted 1910.16.85 Vertical spacing of lateral tics shall. not exceed 16 longitudinal bar diameters, 48 tic bar diameters, or ane half times the least side dimension of the composite member. 1910.168.6 Longitudinal bars located within the tes shall not be fess than 0.01 or more then 0.08 times net area of concrete section 1910.16.8.7 A longitudinal bar shall be located at every comer of ‘rectangular 108s section, with oer longitudinal bars spaced not farther apart than one half the least side dimension of the compos- ite member, 1910.16.8.8 Longitudinal bars located within the ties shall be permitted to be used in computing A, for strength but not in com- puting J, for evalustion of slendemess effects. 1910.17 Bearing Strength. 1910.17.1 Design bearing strength on concrete shall not execed @ (O.85f Ay), except when the supporting surface is wider on all Sides tan the loaded wea, design bearing strength onthe loaded se statlb emit tbe mld by 7, bt ot mare than 2. I 1910.17.2 Section 1910.17 docs not apply to posttensioning an- chorages ‘SECTION 1911 — SHEAR AND TORSION IL0 Nota. itm rasa on sing sree inches (mm), 1” area enclosed by outside perimeter of concrete cross sc: tion, inches squared (rom?), See Section 1911.6. (CHAP. 19, DIV. i 1910.16. con) Ay = ates of reinforcement in bracket or covbel resisting fac- (ored moment [Vi a+ Nae (i-d)] square inches (mi) Ag = gross arca of section, square inches (mm?). ‘Ay. = ates of shear reinfozcement parallel to flexural tension reinforcement, square inches (mm2). total area of longitudinal reinforcement to res ‘square inches (mm). ‘Ay. = area of reinforcement in bracket or cobel resisting ten- sie force Ny, square inches (mm?) Ay = gross, area euclosed by shear flow, inches squared (am), cy = atea enclosed by centertine of the outermost closed transverse torsional reinforcement, inches squared (am). ‘Ape = area of prestressed reinforcement in tension zone, square inches (mm?) ‘Ag. = area of nonprestesed tension reinforcement, squat in- ches (ain?) Ay = area of one leg oa closed stimu resisting vorsion within a distance s, square inches (m2). ‘Ay = area of shear reinforcement within a distance oF area of shoar reinforcoment perpendicular w flexural tension reinforeement within «distance s for dep flexural mem- bers, square inches (mm?). ‘Ag = atea_of sheartrction reinforcement, square inches (am?) axea of shear reinforcement parallel to flexural tension reinforcement withia a distance so, square inches (nu) nar span, distnoe between concentrated loa snd face of supports Width of compression face of member, inches (min). erimeter of critical setion for slabs end footings, in- thes (mim). ‘width of that pat of cross scctioa containing the closed sticeups resisting torsion. ‘web width, or diameter of ctcular section, inches (mm) width of the critical, section defined in Section 1911.12.6.1 messured in the dtecti of the span for which moments ere determined, inches (mm). width of the critical section defined in Section 1911.12.6.1 messured in the direction perpendicular to 61, inches (mm). ize of rectangular ot equivalent rectangular columa, ‘capital or bracket measured inthe diretion ofthe span for which moments are being determined, inches (au). ae of rectangular ot equivalent rectangular column, capital or bracket mensured transverse tthe ditetion of the span for which moments are being determined, in- ches (mi). = = reinforcement ratio producing balanced strain condi- tions. @ = strength reduction factor. 1913.1 Scope, 1913.1.1 The provisions ofthis section shall apply for design of slab systems reinforced for flexure in more than one direction, ‘with of without beams between supparis 1913.1.2 For a slab system supported by columns or walls the di- ‘mensions ey and e2 and the clear span fy shall be based on an elfec~ tive support area defined by the intersection of tie bottom surface of the slab, or the drop panel if these is one, with the largest right ceizcular cone, right pyramid, or tapered wedge whose surlaces are Tocated within the column and capital or bracket and ae oriented no greater than 45 degrees to the axis of the column, 1913.1,3 Solid slabs and slabs with recesses or pockets made by permanent or removable fillers between ribs or joists in two ditec- tions are included within the seope of this section, 1913.1.4 Minimum thickness of slabs designed in accordance with this section shall be as required by Section 1909.53 1913.2 Definitions. 1913.2.1 Colunon strip is a design strip with a width on each side ‘of a column center kine equal 10 0.25! oF 0.25), whichever is less. ‘Colum sitip includes beams, ifany 1913.23 A panel is bounded by column, beam or wall center lines on all sides 1913.24 For monolithic or fully composite construction, « beam includes that portion of slab on cach side of the beam extending a distance equal to the projection of the beam above or below the slab, whichever is greute, but not greater than four times the slab thickness 19133 Slab Reinforcement. 19133.1 Arca of reinforcement in each direction for two-way slab Systems shall be determined from moments at critical sec tions, but shall not be less than required by Section 1907.12. 1913.32 Spacing of reinforcement at critical sections shall not exceed two times the slab thickness, except for portions of slab area of cellular or ribbed construction. In the slab over cellular spaces, reinforcement shell be provided as required by Section 1907.12, 191333 Positive moment reinforcement perpendicular to a dis- coutinvous edge shall extond to the edge of slab and have embed ‘ment, straight or hooked, atleast 6 inches (152. mm) in spandrel beams, columns or walls. 19133.4 Negative moment reinforcement perpendicular to a dis- continuous edge shall be bent, hooked or otherwise anchored, in spandrel beums, columns or walls, to be developed at Eace of sup- port according to provisions of Section 1912. 19133.5 Whore 2 slub is nat supported by a spandrel beam or ‘wall at a discontinuous edge or where u slab cantilevers beyond the support, anchorage of reinforcement shal be permitted within the slab. CHAP. 19, DIV. IE 3130 saat 1913,3.6 In slabs with beams between supports with a value of ct ‘greater than 1.0, special top and bottom slab reinforcement shall be provided at exterior corners in accordance with the following: 1913.3.6.1 The special reinfozcoment ia both top and bottom of slab shall be sufficient to resist a moment equal lo the maximum, Postve moment pe foot of width) (per mete of wt) i the 1913.3.6.2 ‘The moment shall be assumed to be about an axis per- pendicular to the diagonal from the comer inthe top ofthe slab and perpendicular to the diagonal in the botiom of the slab, 1913.3.63 The special reinforcement shall be provided for a dis- tance in cach direction from the comer equal to one fifth che longer span, 1913,3.6.4 The special reinforcement shall be placed in a band parallel tothe diagoual in the top of the slab and a band perpendic~ ‘lar (o the diagonal in the bottom of the slab, Alternatively, the special reinforcement shall be placed in two layers parallel {0 the sides of the slab in either the top or bottom of the slab, 1913.3:7 Where a drop panel is used to reduce amount of negative ‘moment reinforcement aver the column ofa flat slab, size of drop ‘panel shall be in accordance with the following: 19133.7.1 Drop panel shall exiend in exch direction from center fine of support a distance not less than one sixth the spao length ‘measured from cealer lo center of supports in that direction 1913.3.7.2 Projection of drop panel below the slab shall be at least one fourth the slab thickness beyond the drop. 1913.3.7.3 In computing required slab reinforcement, thickness ‘of drop pane! below the slab shal not he assumed grealer than one fourth the distance from edge of drop panel to edge of column o ccoluna capital 1913.3.8 Details of reinforcement in slabs without beams. 1913.3.8.1 In addition to the other requirements of Section 10133, reinforcement in slabs without beams shell have mi ‘mom extensions as prescribed in Figure 19-1 1913.3.8.2 Where adjacent spans are unequal, extension of nega- tive moment reinforcement boyond the face’of support as pre- scribed in Figure 19-1 shall be based on requirements of longer span, 1913383 Bent bars shall be permitted only when depth-span ra- tio permits use of bends 45 degrees or less. 1913384 For slabs in frames not braced against sidesway, ‘cuugths of reinforcement shall be determined by analysis but shall ‘ot be less than those prescribed in Figure 19-1 in the column step, in ‘lion, shall be contiaaous or spliced with Class A splices Tocated as showa in Figure 19-1, At least two of the cokumn stip ‘hottom bars or wires in eack direction shall pass within the columa ‘core and shall be anchored at exterior supports. 19133.86 In slabs with shearheads and in lift-slab construction, at least {wo bonded bottom bars or wires in euch direction shall pass through the shearhcad or lifting collar as close to the column 88 practicable and be continuaus or spliced with a Class A splice ‘Atexterior columns, the reinforcement shall be anchored at the shearheud or lifting collar. 19134 Openings in Slab Systems. 1913.4.1. Openings of uny size shall be permitted in slab systems if shown by analysis chat the design strength is al least equal to the 2187CHAP. 19, DIV. I 191341 1913624 required strength considering Sections 1909.2 and 1909.3, and that all serviceability conditions, including the specified limits on deflections, are mei. 1913.42 In Tew of special analysis as required by Section 1913.4.1, openings shall be permitted in slab systems without beams only in accordance with the following 1913.4.2.1. Openings of any size shall be permitted in the area common to intersecting middle strips, provided total amount of inforcement required for the panel without the opening is mai tained 1913.42.2 In the srea common to intersecting column strips, not ‘more than one eighth the width of eolumn strip in either span shall be interrupted by openings, An amount of reinforcement equiva Jent to that interrupted by an opening shall be added on the sides of the opening. 1913.42.3 In the area common to one column strip and one ‘middle strip, not more than one fourth the reinforcement in either sirip shall be interrupted by openings. An amount of teinforee- ‘ment equivalent to that interrupted by an opening shall be added on the sides ofthe opening. 1913.4,2.4 Shear requirements of Section 1911.12.5 shall be sa- tisfied. 19135 Design Procedures. 1913.51 A slab sysicm shall be desizned by any procedure satis fying conditions of equilibrium and geometric compatibility if shown thatthe desiga strength at every section isa least equal to the required srength considering Sections 1909.2 and 1900.3 and tia all serviceability conditions, including specified limits on de floctions, ere met. 1913.5.1.1 Design of a slab system for gravity loads including the slab and beams (if any) between supports aud supporting columns for walls forming orthogonal frames, by cither the Direct Design ‘Method of Section 1913.6 or the Equivalent Frame Method of ‘Section 1913.7, shall be permitted. 1913.8.1.2 For lateral loads, analysis of unbraced frames shall take into account effects of cracking and reinforcement on stif= ‘ness of frame members. 1913.5.1.3 Combining the results of the gravity loud analysis ‘with the Zesuits of the lateral oad analysis shall be permitted, 1913.52 ‘The slab and beams (if any) between supports shall be proportioned for faciored moments prevailing at every section. 1913.53 When gravity load, wind, earthquake or other lateral forces cause transfer of moment between slab and column, a frac- tion of the unbalanced moment shall be transferred by flexure in accordance with Sections 1913,5.3,2 end 1913,5.3.3, 1913.33.1 Fraction of unbalanced moment not transferred by flexure shall be transferred by eccentricity of shear in accordance with Section 1911.12.6, 1913.53.2 A fraction of the unbalanced moment given by yh shall be considered to be transferred by flexure within an effective slab width between lines that are one and one-half slab or drop pane] thickness (1.54) outside opposite faces of the column or cap- ital, where My is the moment to be transferred and 1 V+ ?f, ybi/bs 1913.5.3.3 For unbalanced moments about ao axis parallel to the ‘edge at exterior supports, the value af y by Formula (13-1) shall 2198 " 3) 1997 UNIFORM BUILDING CODE bbe permitted to be increased up to 1.0 provided that at an edge ‘support docs not exceed 0.75:pV. or ata corner support does not ‘exceed 0.50V. For unbalaaced moments at interior supports, and for unbalanced moments about an axis twansverse to the edge at ‘exterior supports, the value of yin Formula (13-1) shall be per- mitted to be increased by up to 25 percent provided that Vj, athe support docs not exceed 049¥.. The reinforcement rato p, within tho effective slab width defined in Section 1913.5.3.2, shall not exceed 0.375 py. No adjustments to ¢shall be permitted for pre- stressed slab systems. 1913.5.3.4 Concentration of reinforcement over the column by ‘loser spacing or additional reinforcement shall be used to resist ‘moment on the effective slab wich defined in Section 1913.5.3.. 1913.54 Desiga for transfer of fond from slab to supporting col- ‘ums or walls through shear and torsion shall be in accordance with Sections 1911.0 through 1911.12. 19136 Direct Design Method. 1913.6.1 Limitations, Design of slab systems within the follow- {ng limitations by the Direct Design Method shall be permitted: 1913.6.1.1 There shall be a minimum of three continuous spans in each direction. 1913.6.1.2 Panels shall be rectangular, with a ratio of longer to shorter span center-to-center supports within a panel not greater ‘haa 2, 1913.6.13 Successive span lengths centerto-center supports in ‘each direction shall not differ by mote than one third the longer span, 1913.6.L.4 Offset of columas by a maximum of 10 percent of the span (in direction of offset from either axis between cente ‘af suocessive columns shall be permitted. 1913.6..5 All loads shall be due to gravity only and uniformly distributed over an entire panel. Live load shall not exceed two times dead lead. 1913.6.1.6 For a panel with beams between supports on all sides, the relative stiffness of beams in two perpendicular directions ah? ai? shall not be less than 0.2 or greater than 5.0. 1913.6.1.7 Moment redistribution as permitted by Section 19084 shall not be applied for slab systems designed by the direct design method, See Section 1913.6.7. 1913,6.1.8 Variations from the limitations of Section 1913.6.1 shall be permitted if demonstrated by analysis that requirements of Section 1913.5.1 are satisfied 1913.62 Total factored static moment for a span, 1913.62.1 ‘Total factored static moment fora span shall be deter- ‘mined in a strip bounded laterally by centerline of panel on each sido of center line of supports. 1913.62.2 Absolute sum of positive and average negative fac- tored moments in each direction shell not be less than 3-2) M, = 1913.6.2.3. Where the transverse span of panels on the centerline of supports varies, >in Formula (13-3) en asthe average of adjacent transverse spans. 1913.6.2.4 When the span adjacent and parallel to an edge is be- {ng consicred, the distance from edge to panel center fine shall be substituted for in Formula (13-3). e1997 UNIFORM BUILDING CODE 1913.62. Clear span fy shall extend from face to face of col- tumns, capitals, brackets or walls, Value of f used in Formula (43-3) shall not be less than 0.65). Circular or regular polygon- shaped supports shall be treated as square supports with the same 1913.63 Negative and positive factored moments. 1913.6.3.1 Negative factored moments shall be located at face of, rectangular supports. Circular or regular polygon-shaped supports ‘Shall be treated as square supports with the same area 1913.63.2 In an interior span, total static moment Mj, shall be distributed as follows: Negative factored moment | +. 065 Positive factored moment 035 1913.63.3 In an end span, total factored static moment Mf shall aI a a eager | Sa ager eae, | lunniinaa| sopeots | Bae ime incamnine Esouimmn | 075 | 070 | 07 | om | 068 Pes edad oo oss _| ost | os | os | 03s Eco aga faaccdmaeet | 0 | ose | o26 | os | ass 1913.63.4 Negative moment soctions shall be designed to resist the larger of the two interior negative factored moments deter- ‘mined for spans framing into a common support unless an analysis is made to distribute the unbalanced moment in accordance With stiffness of adjoining elements 1913.6.3.5 Balge beams or edges of slab shall be proportioned to sesist in lorsion their share of exterior negative factored moments. 1913.6.3.6 The gravity load moment to be transferred between slab and edge column in accordance with Section 1913,5.3.1 shall beta, 1913.64 Factored moments in column strips. 1913.464.1 Column strips sll be proportioned to resist the fol= lowing percentage of inferior negative factored moments: [ae cd ae oath =0 7S ro 7% (estat) = 1.0 90 6 4s Linear interpolations shall be made between Values shown. 1913.6.4.2 Column strips shall be proportioned to resist the fol- lowing percentage of exterior negative factored moments: co a @ ze =o [100 100 100 (oat) =0 x = mot ie 1 eatyh) = |_Bee 2 is" pez | 5 e Linear interpolations shall be made between values shown, (CHAP, 19, DIV. It ‘ietse2s 191368, 1913.643 Where supports consis of colurans oF walls extending fora distance equal to or greater than three fours the span length ‘used to compute Mp, negative moments shall be considered to be uniformly distributed across fs 1913.64.4 Column strips shall be proportioned to resist the fol- owing percentage of positive factored moments: i mo 7) a eit @ oo @ Geuighy = 1.0 0 8 45 Linear interpolations shall be made between values shown: 1913.64 For slabs with beams between supports, the slab por tion of column strips shall be proportioned to resist (hat portion of column strip moments not resisted by beams, 1913.65 Factored moments in beams. 1913.6.5.1. Beams between supports shall be proportioned to re- sist 85 percent of coluinn stxip moments if ( Me ae a= Mom W Se connection — (21-1) Dynamic amplification factor \ shall be taken as 1.0. 1921274 Column-to-column connection. The strength of such connections shall comply with Section 1921.2.7.3 with p taken a3 1.4. Where column-to-column connections occur the columns shall be provided with transverse reinforcement as specified in Sections 19214.41 though 1921-44.3 over ther fall height f the {factored axial compressive force in these members, including seis mic effects, exceeds Ay f'.0. EXCEPTION: Whore cohunnt-colunn connection ie ocated ihn the mide hid of he cola clea eh he folowing shalt “pny: (1) Tre dvgn momone rent fhe connect sl ot ees than tes the aris iy ore cola within the sar) Aig and (2) the design shen song ofthe conecton sal tot bees Pan that determined per Section 1921431 1921275 Columa-face connection, Any strong connection located ouiside the middie half of « bear span shall be a wet com- nection, unless « dry connection can be substantiated by approved ‘oyelic test results. Any mechanical connector located within such a coluran-face strong connection shall develop in tension or com pression, as required, at least 140 percent of specified yield strength, fy of the bar. 1921.3 Flexural Members of Frames. 1921.1 Scope. Requirements of this section apply to frame ‘memibers (1) resisting earthquake-induced forces and (2) propor- tioned primarily to resist flexure. These frame members shall also satisfy the following conditions: 1921.3.1.1 Factored axial compressive force on the member shall, not exceed (Ap/'”/10), 19213.1.2. Clear span for the members shall not be less than four limes its effective depth, 1921.3.1.3 The width-o-depth ratio shall not be less than 0.3, 1921.3.14 The width shell not be (1) less than 10 inches (254 mm) and (2) more than the width of the supporting member (mea- sured on a plane perpendicular to the longitudinal axis ofthe flex- tural member) plus distances on each side of the supposting member wot excoding te forth of the dept of the feral 1921.3.2. Longitudinal reinforcement. 19213.2.1 At any section of a flexural member, except as pro- vided in Section 1910.53, for top as well as for bottom reinforce- ‘ment, the amount of reinforeement shall not be less than that given by Formula (10-3) but not ls than 200 yf, (For SI: 1.38 Dya/ 2158 11907 UNIFORM BUILDING CODE fi) and the reinforcement ratio, p, shall not exceed 0.025. At least ‘640 bars shall be provided continuously, both top and bottom. — 1921.3.22 Posiive-moment strength at joint face snall not be Jess than one half of the negative-moment strength provided at that fac othe joint. Nether the negative nor the posiive-moment strength at any section along member length shall be less then one fourth the maximum moment strangth provided at face of either joint. 1921.3.2.3 Lap splices of flexural reinforcement shall be por- ‘mitted only if hoop oF spiral reinforcement is provided over the lap length. Maximum spacing of the transverse reinforcement enclos- ing the lapped bars shall not exceed 4 04 inches (102 mm). Lap splices shall not be used (1) within the joints, (2) wiin a distance of twice the member depth from the fice of joint, and (3) at loca- tions where analysis indicates flexural yielding caused by inelas- tic lateral displacements ofthe frame. 1921324 Welded splices and mechanical connections. shall conform to Section 1921.2.6.1 1921.33 ‘Transverse reinforcement. 1921.3.3.1 Hoops shall be provided in the following regions of frame members 1, Over a length equal to twice the member depth measured from the face of the supporting member toward midspan, at both ‘ends of the flexural members. 2. Over lengths equal to twice the member depth on both sides ‘ofa section where flexural yielding may occur in connection with inelastic lateral displacements of the frame. 1921.33.2 The first hoop shall be located aot more than 2 inches. (61 mm) from the face of a supporting member. Maximum spac- {ng of the hoops shall not exceed (1) 4/4, (2) eight times the diame ter of the smallest longitudinal bars, (3) 24 times the diameter of the hoop bars, and (4) 12 inches (305 mm) 1921.33.3 Where hoops ate required, longitudinal bars on the perimeter shall have lateral support conforming to Section 1907.10.53. 1921.33.4 Where hoops are not required, stirups with seismic hooks at both ends shall be spaced at a distance not more than d/2 throughout the length of the member, 1921,33.5 Stimrups or tes requited to resist shear shall be hoops over lengths of members as specified in Sections 1921.3.3, 1921.4.4 and 1921.5.2 1921.33.6 Hoops in Mexural members shall be permited to be ‘made up of two picces of reinforcement: a stirup having seismic hhooks at both eads and closed by a erosste. Consecutive cxossies engaging the same longitudinal bac shall have their 90-degree hhooks at opposite sides ofthe flexural member. I the longitudinal reinforeing bars secured by the ersstes are confined bya slab on only one sie ofthe flexural frame member, the 90-degree hooks Of the crossties shal all be placed on thats 1921.34 Shear strength. 1 1921.3.4.1 Design forces. The design shear forces Vz shall be determined from consideration of the static forces on the postion ofthe member between faces ofthe joiat. Ht shall be assumed that ‘moments of opposite sign corresponding i probable strength Myy ct at the joint faces and thatthe member is loaded with the tbc tary gravity load along its span. 1921342 Transverse reinforcement. Transverse. reinforce- ‘ment over the lengths identified in Section 1921.31 shall be pro- portioned to resist chear assuming V.=0 when both of the following conditions occur:1997 UNIFORM BUILDING CODE 1. The enrthquake-induced shear force calculated in accord- ance with Section 1921,3.4.1 represents one-half or moze of the ‘maximum required shear strength within those lengths. 2. The factored axial compressive force including earthquake ceffets is less than Apf'e/20. 1921.4 Frame Members Subjected to Bending smd Axial Load. 1921.4.1 Scope, The requirements of Sect frame members (1) resisting earthquake- having a factored axial fozee exceeding Ayf’/10. These frame ‘members shall also satisfy the following conditions: 192L.4.L.1 ‘The shortest cross-sectional dimension, measnyed on a straight line passing through the geomeitic centroid, shall not be less than 12 inches (305 mm), 1921,4.1.2 The ratio ofthe shortest cross-sectional dimension to the perpendicular dimension shall not be less than 0.4. 1921.42 Minimum flexural strength of columns. 1921.4.2.1. Flexural strength of eny column proportioned to resist 1 factored axial compressive force exceeding Ayf'c/10 shall satisfy Section 1921.42.2 or 1921.82. Lateral strength and stiffness of columns not satisfying Section 1921,4,2.2 shal he ignored in determining the calculated strength and stiffness of the structure but shall conlonm to Section 1921.7. 1921.4.2.2 The flexural strengths of the columns shall satisfy Formula (21-1) EM. = C/9EMy er) WHERE: EM, = sum of moments, at the center of the joint, corresponding to the design Dexural strength of the columns framing into that joint. Column flexural strength shal be caleu- Ited for the factored axial force, consistent with the di- rection ofthe lateral forces considered, resulting io the lowest floxural strength Mg = sum of moments, at the center ofthe join, corresponding, to the desiga flewural sirengths of the girders framing {nto that joint Flexural strengths shall be suramed! such that the colunnn mo: iments oppose the beam moments, Formula (21-1) shall be sat fied for Beam moments acting in both directions in the vertical plane of the ame considered. 1921423 If Section 1921.4.22 is not satisfied at a joint, col _umns supporting reactioas from that joint shall be provided with transverse reinforcement as specified in Section 1921.44 over their full height 1921.43 Longitudinal reinforcement. 1921.43.1 The reinforcement ratio fy shall not he Tess than 0.01 and sball not exceed 0.06, 1921432 Welded splices and mechanical connections shall ‘conform to Section 1921,2.6.1. Lap splices shall be permitted only ‘within the center half of the member length and shall be propor- tioned as tension splices. 1921.44 Transverse reinforcement, 1921.4.4.1 Transverse reinforcement as specified below shat! be ‘provided unless 2 larger amount is required by Section 1921.45, 1. The volumetric ratio of spiral or circular hoop reinforce- iment, fy shall not be less than that indicated by Formuls (21-2). CHAP. 19, DIV. II e132 qe2t8.46 = O12F ifn 1-2) and shall not be less than that required by Formula (10-5), 2. The total cross-sectional area of rectangular hoop seinfores- rent shall not be less than dat given by Formulas (21-3) and Q-4) Ay = 03 Gh f/f[As/Aa) ~ 1] 213) Ay = 0.09 (6h f./fud er) 3, ‘Transverse reinforcement shall be provided by either single or overlapping hoops. Crosties ofthe same bar size and spacing 8s the hoops shall be permitted (be used. Each ead of the crossie Shall engage a peripheral longitudinal einforeing bas, Consecu- tive crostes shall be alternated end for end along the longitudinal reinforcement. 4, Ifthe dosign strength of momber core satistes the require- iment of the specified loading combinations including earthquake ‘effect, Formulas (21-3) and (10-5) need not be satisfied. . Any area ofa column which extends more than 4 inches (102 ‘mm) beyond the confined core shall have minimum reinforcement ‘ns required for nonseismic columns as specified in Section 1921.7 6. Where the calculated point of contraflecure isnot within the Iniddle half of the member clear height, provide transverse re inforcement as specified in Sections 1921 434.2 Hems I through 3, ‘ver the fll height ofthe member. 1921.4.4.2 ‘Transverse reinforcement shall be spaced at distances not exceeding (1) one-quarlet minimum member distance and (2) ‘Finches (102 mm). Anchor bolts set in the top ofa colunn shall be enclosed with tes as specified in Section 1921.4.4.8. 1921.44.23 Crossties or legs of overlapping hoops shall not be spaced more than 14 inches (356 mm) on center in the direction perpendicalet to the longitudinal axis ofthe structural member. 1921444 Transverse reinforcement in amount specified in See- tions 1921,4,4.1 through 192144. shall be provided over 2 mnuth J, from each joint face and on both sides of any scetion ‘where flexural yielding may acear in connection with inelastic lat- eral displacements of the frame. The lengt shal not be less than (1) the depth of the member atthe joint face ora the section where flexural yielding may ocear, 2) one sixth ofthe clear span of the rmeraber, and (3) 18 inches (157 mm). 1921AAS Columns supporting reactions from discontinued stiff ‘members, such as walls, shall be provided with transverse re- jnforeement as specified in Sections 19214.4.1 dough {1921,44.3 over thei fll height beneath te level at which the dis- continuity occurs if the factored axial compressive force in these members, including esrthquake effect, exceeds Ag/'/10. Trans- ‘Verse reinforcement as specified in Sections 19214.4.1 through 1921.4.4.3 shal extend into the discontinued! member fo atleast the development length ofthe largest longitudinal rinforcement in the column in accordance with Section 1921.5.4. Ifthe lower end of the column terminates on a wall, Wansverse reinforcement as specified in Sections 1921.4.4.1 through 1921.4.4.3 shall ex- tend into the wall for at east the development length ofthe largest longitudinal reinforcement inthe colunun atthe point of termina- tion. Ifthe column terminaes on a footing or mal, transverse sein- forcement as specified in Sections 1921.44.1 through 1921.44.3 stall extend atleast 12 inches (305 mm) into the footing oF mat 1921.4.4.6 Where Wansverse reinforcement as specified in See- tions 1921.4.4.1 through 1921.4.4.3 is not provided throughout ‘the full length of the coluran, the remainder of the column length shall contain spiral or hoop reinforevment with center-to-center Spacing not exceeding the smaller of six times the diameter of the {ongitudinal column bars o 6 inches (152 x5), 2189CHAP. 19, DIV. It 1921.647 1921543, I92.44.7 At any section where the design strength, Py, ofthe column i ess than the sum ofthe shears V, computed in aceord- ‘ance with Sections 1923-41 and 1921.45. for all the bears runing into the column above the level under consideration, transverse reinforcement as specified in Sections 1921 4.4.1 ‘through 1921.44.3 shal be provided. For beams framing into op- posite sides ofthe column, the moment components may be as- sumed to be of opposite sign. For the determination ofthe design strength, $B, ofthe column, these moments may be assumed to re- sul from the deformation ofthe frame in any one principal axis 1921448 Ties at anchor bolts. Anchor bolts which are set in the ‘op of a column shall be provided with ties which enclose at least four vertical column bars. Such ties shall be in accordance with Section 1907.1,3, Item 3, shall be within 5 inches (127 mm) of the top of the column, and shalt consist of ai least avo No, 4 or three No.3 bars. 1921.45 Shear strength requirements, 1921.4.5.1 Design forces. ‘The design shour force V, shal be de- termined from the consideration of the maximum forces that can be generated atthe faces of the joints at each end of the member. ‘These joint forces shall be determined using the maximam prob- able moment strengths, Myr of the member associated with the range of factored axial loads on the member. The member shear need not exceed those determined from joint strengths based on the probable moment strength, Myy, of the transverse members framing in the joint. In no case shall ¥z be Tess than the factored shcar determined by analysis of the structure. 41921.4.52 ‘Transverse reinforcement over the lengths J, identi- fied in Section 1921.4.4.4, shall be proportioned to resist shear assuming V, = 0 when both of the following conditions occur 1. The earthquake-induced shear force calculated in accord- ‘ance with Section 1921.4.5.1 represents one-half or more of the ‘maximum required shear strength within those lengths. 2, "The faciored axial compressive force including earthquake effects is less than Agf 20. 19215 Joints of Frames. 1921.51 General requirements, 1921.8.1.1 Forces in longitudinal boum reinforcement at the joint face shall be determined by assuming that the stress in the flexural tensile reinforcement is 1.25. 1921.5.1.2 Sirength of joint shall be governed by the appropriate strength-reduction factors specified in Section 1909.3, 1921.5.1.3 Beam longitudinal reinforcement terminated in a col- tum shall be extended to the far face ofthe confined columa core land anchored in tension according to Sectien 1921.5.4, and in ‘compression according to Seetion 1912. 1921.5.1.4 Whore longitudinal beam reinforcement extends through a beam-columa joint, the column dimension parallel to ‘the beam reinforcement shall not be less than 20 times the diame- {er ofthe largest longitudinal bar for normal-weight concrete, For lightweight concrete, the dimension shall not be less than 26 times te bar diameter. 1921.52 Transverse reinforcement. 1921.5.2.1 ‘Transverse hoop reinforcement as specified in Sec tion 1921.4.4 shall be provided within tho joint, unless the joint confined by structural _membors as specified in Sectio 1921.5.2.2. 2160 1997 UNIFORM BUILDING CODE 41921.5.2.2 Within the depth of the shallowest framing member, transverse reinforcement equal to atleast one half the amoust re= uired by Section 1921.4.4.1 shall bo provided where members frame into all four sides ofthe joint and whore cach member width és at Jeast three fourths the coluran width. At these locations, the spacing specified in Section 1921.4.4.2 shall be permitted to be increased to 6 inches (152 mm), 1921.5.2.3 Transverse reinforcement as required by Section 1921.4.4 shall be provided through the joint \o provide confine- ‘ment for fongitudinal beam reinforcement outside the coluam core if such confinement is not provided by a bear freming into the joint 1921.53 Shear strength. 1921,53.1 ‘The nominal shear strength of the joint shall not be taken greater than the forces specified below for normal-weight aggregate concrete. For fits confined on all four faces Fea, (Gor St: 1.66 F724) For jai confined oo tre faces or on two ‘opposite faces 1s VFA, or Sk: 1.25 FA) 12 FA, (For St: 1.00 /f2A)) ‘A member that frames into a face is considered ta provide eon- finement to the join if at least three fourths ofthe face ofthe joint is covered by the framing member. A joint is considered (o be con- fined is such confining members frame into all faces of the join. For others 1921.5.3.2 For lightweight aggregate concrete, the nominal shear strength ofthe joint shall nt exceed three fourths of the limits for normal-weight aggregate concrete, 1921.54 Development length for reinforcement in tension. 1921.54.1 The development length, fg, fora har with a standard ‘90-degree hook in normal-weight aggregate concrete shall not be Jess than 8d, 6 inches (152 mm), and the length requited by For- rnula 1-5). lay = feds 5 Fe ForSk: ta = Bl {or bar sizes No, 3 through No. 11 For lightweight aggregate concrete, the development length for a bar with a standard 90-degree hook shall not be less than 1d, 75 inches (191 mm), and 1.25 times that required by Formula Q15). ‘The 90-degres hook sball be located within the vonfined core af ‘column or of a boundary member, 1921.84.2 For bar sizes No. 3 through No. 11, the development length, ly for a straight bar shall not be less than (1) 2.5 times the length required by Section 1921.5.4.1 if the depth af the concrete ‘east in one lift bencath the bar does not exceed 12 inches 0S ‘mm), and (2) 3.5 times the length required by Section 1921.34.1 if the depth of the concrete cast in one lift Beacath the har exceeds 12 inches (305 mm), 1921.5.4.3 Suraight bars terminated at a joint shall pass through the confined core of a column or of a boundary member. Any por- tion of the straight embedent length not within the confined core shall be increased by a factor of 1.6. ars)11997 UNIFORM BUILDING CODE 1921544 If epoxy-coated reinforcement is used, the develop- tment lengths io Sections 1921.5.4.1 through Section 1921.5.4.3 shall be multiplied by the applicable factor specified in Section 1912.24 oF 1912536, 1921.6 Shear Walls, Diaphragms and ‘Trusses. 1921.6.1 Scope. The requirements of this section apply to shear ‘walls und trusses serving as parts ofthe earthquake-force-resisting systems as well as to diaphragms, struts, ties, chords and collector ‘members which transmit forees induced by earthquake, 1921.6.2 Reinforcement, 1901.62. The reaforcemen ti, for sear walls shal ot te ean O05 alos giana sad anes se. the design seat fore does ant exceed Ay (For St {108A ff), the minim enorcomen fr shear walls shall DOM etn wilh Seaton [OU he minim renore aoa er eau dapvags sl be ncononaanee wth ae Rentrctnent spcing cach way nse alls se aga al nt cacoad cies 7 am, Ree. ae or ahem snengin sal be cinus end shal be “Feotbued aro the sea plane 1921.6.2.2 Aceas tyo curtains of reinforcement sll be wsed in 4 wal the ineplane factored shear force assigned tothe wall ex- ceeds 2A. F (Hor St: 0.1664,,F), When Vz in the plane of the wall exceeds Aq {fe (For 0.084. of <), horizontal reinforcement terminating at the edges of shear walls shall have a standard hook engaging the edge rei forcement, or the edge reinforcement shall Be enclosed in “U” ‘stirrups having the same size and spacing as, and spliced 10, the horizontal reinforcement. 1921.6.2.3 Structural-truss clements, strus, ties and collector elements with compressive stresses exceeding 0.2 f shall have special transverse reinforcement, as specified in Section 1921.44, ‘ver the total length of the element. The special transverse rein forcement may be discontinued ata section where the calculated compressive slress is Tess thaa 0.15 fc, Stresses shal be calculated for the factored forces using a linearly elastic model and .gross-section properties of the elements considered. 1921.6.2.4 All continuous reinforcement in shear walls, dia phragm, trusses, struts, ties, chords and collector clements shall be anchoted or spliced in gecordance with the provisions for rein- forcement in tension as specified in Section 1921.5.4 1921.63 Design forees, The design shear force ¥, shall be ob- tained from the lateral load analysis in accordance with the fac- tored loads and combinations specified in Section 1909.2 and as ‘modified in Section 1612.21. 1921.64 Diaphragms. See Sections 1921.6.11 and 1921.6.12. 1921.65 Shear strength. 1921.6.5.1 Nominal shear strength of shear walls and dia: phragms shall be determined using either Section 1921.65.2 ot 1921.653. 1921,6.8.2 Nominal shear strength, Vq, of shear walls and dia pphragms shal be assumed not to exceed the shear force calculated from Va = Aw QvFe + Pal) V, = Ae (0.166 fF + Pal) (2-6) For Si: ‘CHAP. 19, DIV. UL yeaa 121884 1921.65. For walls (diaphragms) and wall (iaphregm) se3- nents having 2 ratio Of (lle) Kos than 20, nominal shear {stength of wall (diaphragm) shal be determined from Formula ory Va = Ac(aedlFe + Pal) For Si: Vy = Ae (0.08a./F% + Pah Where the coefficient op vasislinarly fom 3.0 for ily 2.0 for Ib = 2.0. 1921.6.5.4 In Section 1921.6.5.3 above, the value of ratio (yyy) sed for determining Vy for segments of wall or diaphragm shal be he largest of the ratlos forthe entixe wall (digphragm) and the segient of wall (diaphragm) considered. 1921.65 Walls diaphragins shall have distributed shea forcement providing resistance in two orthogonal directions in tho plane of the wall (diaphragm). If the ratio (/by/ly) does not exceed 370, reinforcement ratio fll aot be less than reinforcement 2- tio 1921.65.6 Nominal shear strength of all wall piers sharing a ‘common lateral force shall not be assumed t0 exceed BA. yf (For Sk: 0.664 jf) where Ac, isthe total cross-sectional area fnd the nominal shear strength of any one of the individual wall piers shall not be assumed to exceed 10A,/f'. (For Sl: os ff) where Aap teptesents the cross-sectional area of the pier considered. en Sto 1921.65.7 Nominal shear stent of horizontal wall sgmens hull not be assumed to excecd IM, {For St: 0.884 iF) Shere Ay tepresens the cros-seciona area ofa horizon wall seamen 1921.66 Design of shear walls for flesural and axial oad, 19216461 Shear walls and portions of shear walls subject to combined flexural and axial loads shail be designed in accord- ‘ance with Sections 1910.2 and 1910.3, except Section 1910.3.6 ‘and the nonlinear strain requirements of Section 1910.2.2 do not ‘apply. The sirength-reduction factor 6 shall be in accordance with Section 1909.3. 1921.6.62 The effective Range width 10 be wsed in the design of 1, Cor Fshaped sections shall not be assumed fo extend fur- ther rom the face ofthe web than (1) one half the distance to an ‘tdicen shear wall web, or (2) 15 percent ofthe total wall height forse flange in compresion or 30 percent of the teal wall height Jor the flange in tension, not to exceed the fot projection of the fange. 1921.6.6.3 Walls and portion of was with Py > 0.35Pp shall not bre considered to contrat tothe ealulated strength of te tru fe for resisting earthguake-induced forces. Such walls shall conform othe requirements of Section 1631.2, lem 4 1921.64 Shear wall boundary zone detail reuirements as de- ined in Section 1921 6.6.6 need not be provided i shear walls or Jortions of shear wails meeting te following conditions: 1. Py $0.10Agfs for geometrically symmetrical wal sections Th = 0.0SA,f for geomerricnly unsymmetrical wall see- and either 2481So eet 1921.6.64 1921866 IVS Dey (Freand Me 3 For St: Vib Ve $0.25 WF) ‘Shear walls and portions of shear walls not meeting the condi- tions of Section 1921.6.6.4 and having P, < 0.35P, shall have ‘boundary zones at each end a distance varying linearly from 0.25 ly t0 0.15 by for P, varying from 0.35 P, to 0.15 Py. The boundary zone shall have minimuan length of 0.15 by and shall be detailed in accordance with Section 1921.6.6.6. 41921.6.6.5 Alternatively, the requirements for boundary zones in shear walls or portions of shear walls not meeting the conditions ‘of Section 1921.6.6.4 may be based on determination of the com pressive strain levels at edges when the wall or portion of wall is ‘Subjected 10 displacement levels resulting from the ground mo- tions specified ia Section 1629.2 using cracked section properties ‘and considering the response modification effects of possible non- linear behavior of the building. Boundary zone detail requirements as defined in Section 1921.6.6.6 shall be provided over those portions of the wail where compressive strains exceed 0.003. In no instance shall designs be permitted in which compressive strains exceed Eyay WHERE: 1015 1-8) J. Using the displacement of Section 1921.6.6.5, determine the ‘curvature of the wall cross section at each location of potential flexural yielding asswning the possible nonlinear response of the wall and its elements. Using a strain compatibility analysis of the wall cross section, determine the compressive strains resulting from these curvatures. 2. For shear walls in which the flexural limit sta response is governed by yielding at the base of the wall, compressive strains at wall edges may be approximated as follows: Determine the total curvature demand (¢,) as given in Formula. (21-9): A, “amt ion, 1-9) WHERE: Clg = neutral axis depth at Py and My = height ofthe plastic hinge above critical section and Which shall be established on the basis of substan- tiated test data or may be alternatively taken at 0.5hy 12D +05L+E. elastic design displacement at the top of the wall using gross section properties and code-specified seismic forces. Ai = inelastic deflection at top of wall. = Ay -dy Ay = total deflection atthe top of the wall equat ro Ay, us- ing cracked section properties, or may be taken as 2Aye using gross section properties. displacement at top of wall corresponding to yielding Of the tension reinforcement at critical section, oF ‘may be taken as (M'q/Mg)A g, where Mg equals un- ‘Factored moment at critical section when top of wall is displaced A g. M'y is nominal flexural strength of critical section at Py = yield curvature which may be estimated as 0.003/y, {feds less than or equal to 0.003Ke'y boundary zone details as defined in Section 1921.6.6.6 are not required. If ¢ exceeds .0Ci8Ie'y, the compressive strains may be assumed to vary Pu = Ag = 4) = 2162 1987 UNIFORM BUILDING CODE linearly over the depth c's and have maxinuen vale equal to the Product ofc, and dy 1921.6.66 Shear wall boundary zone detail requirements. When required by Section 1921.6.6.1 through 1921.6.6.5, bound. ‘ary zones shall meet the following: 1, Dimensional requirements 1.1 All partions of the boundary zones shall have a thick- ness of b/I6 oF greater 1.2 Boundary zones shall extend vertically a distance equal to the development length of the largest vertical bar within the boundary zone above the elevation where the requirements of Section 1921.6.6.4 or 1921.6.6.5 are met. Extensions below the base of the boundary zone shalt ‘conform to Section 1921.4.4.6. EXCEPTION: The boundary zone reinforcement need not extend “above he base ofthe boundary one adistnce greater thane large? Othe oF MAN 1.3. Boundary zones as determined by the requirements of Section 1921.6.6.5 shall have a minimum length of 18 inches (457 mm) at each end ofthe wall or portion of. wall 14 Ink. Le, C-or Fshaped sections, the boundary zone at each end shall include the effective flange width and shalt extend at least 12 inches (305 mm) into the web. 2. Confinement reinforcement. 2.1 All vertical reinforcement within the Boundary zone shall be confined by hoops or eross ties producing an ‘area of steet not less than: Ay = 009sK.f cn 21-10) 22 Hoops and cross tes shall have a vertical spacing not ‘reaier than the smaller of 6 inches (152 mm) or 6 diam eters of the largest vertical bar within the boundary zone. 2.3: The ratio ofthe length to the width ofthe hoops shall not exceed 3. All adjacent hoops shall be overlapping 24 Cross ties or legs of overtapping hoops shall not be spaced further apart than 12 inches (305 mmx) along the veal 25 Alternate vertical bars shall be confined by the comer ef ahoop or cross tie. 3. Horizontal reinforcement 3.1 All horizontal reinforcement terminating within a boundary zone shall be anchored in accordance with Section 1921.6.2 32 Horizontal reinforcement shall not be lap spiced within the boundary zone. 4. Vertical reinforcement 4.1 Vertical reinforcement shall be provided to satisfy alt tension and compression requirements, 42. Area of reinforcement shall not be less than 0.005 times the atea of boundary zone or less than two No. 5 bars at each edge of boundary zone. 43 Lap splices of vertical reinforcement within the bound- ‘ary zone shall be confined by hoops or cross ites, Spac- ing of hoops and cross ties confining tap-spliced reinforcement shall not exceed 4 inches (102 mm).1997 UNIFORM BUILDING CODE 1921.6.6.7 Welded splices and mechanical connections of longi {udinal reinforcement in the boundary zone shall conform to Sec tion 1921,2.6.1 1921.6.7 Boundaries of structural diaphragms. 1921.67. Boundary clements of structural diaphragms shall be proportioned to resist the sum of the factored axial force acting in the plane of the diaphragm and the force obtained from dividing the factored moment at the section by the distance between the edges of the diaphragm at that section 1921.6,1.2 Splices of tensile reinforesment inthe boundaries and collector elements of all diaphrogms shall develop the yield strength of the reinforcement. Welded splices and mechanical cconncetions shall conform to Section 1921.2.7.1 1921.67. Reinforcement for chords and collectors at splices ‘and anchorage zones shall have a minimum spacing of three bar diameters, but not less than 1" inches (38 mm), and a minimum ‘concrete cover of ovo and one-half bar diameters, but not less than inches (51 mm), and shall have transverse reinforcement as spe- tified by Section 2911.5.5.3, except as required in Section 1921.6.23. 1921.68 Construction joints. 1921.6.8.1 All construction joints in walls and diaphragms shall conform to Section 1906.4, and contact surfaces shall be rough- ened as specified in Section 1911.7.9. 1921.69 Discontinuous walls. Columns supporting discontin- uous walls shall he reinforced in accordance with Section 1214.45, 1921.6.10 Coupling beams. 1921.6.10.1 For coupling beams with Ipld = 4, the design shall ‘conform to the requirements of Sections 1921.2 and 1922.3. It shall be permitied to waive the requirements of Sections 1921.3.1.3 and 1921.3.1.4 if ftcan be shown by analysis that lar- ‘eral stability is adequate or if alternative means of maintaining Interal stability is provided. 1921.6.10.2 Coupling beans with Iqld <4 shal be permitted to be reinforced with two intersecting groups of symmetrical diggo- ral bars. Coupling beams With Id < and with fectored shear force Vj, exceeding 4 Jf". bya (For SI: 0.33 JF". bud) shall be reinforced with ovo intersecting groups of symmetrical diagonal boars. Fach group shall consist of a minimum of four bars assembled ina core with a lateral dimension of each side not less ‘Han by [2 or 4 inches (102 min). The design shear strength, Va of these Coupling beams shall be determined by: Wp = 2h Sincdg = 1G YF Oyd — (2E-IT) ForSt: — @Vq=26 fp sing = 0.830, /F bord WHERE: = the angle beoween the diagonal reinforcement and the longitudinal axis. ‘Avg. = the toil area of reinforcement ofeach group of diagonal bars 6 = 085, EXCEPTION: The desiga of coupling beans need no comply with the reeirnents for diagona enforcement can be how tha ail tte of he coupling beans wil not inpat the vertical load carrying ‘Capac of te stractre th ogres rm te sracture, ore ince ‘fhonstrctael components and connections. Te analysis shall ake (eo accra the eft ft falar of the coupling beams on founda Ton tion and overall systen displacomens. Des srengh of eat ‘CHAP. 19, DIV. It 1021667 21rd x at fe eo sptomemniatarats anm bay4ies tah go ony pt he aLeits Soe i en Sas Sud farmer er aa et ifs rented crete Sree hat nl hy Saal pce npc 1921.6.104 Reinforcement paraltel and transverse to the longi- tudinal axis shall be provided ond, ax a minimum, shall conform to Sections 1910.5, 1911.8.9 and 1911.8.10. 1921.6.10.5. Contribution of the diagonat reinforcement to nomt- nal flecural serength of the coupling beam shalt be considered. 1921611 Floor topping. A cast-in-place topping on a precast floor system may serve as the diaphragm, provided the ‘east-in-place topping acting alone is proportioned and detailed 10 resist the design forces. 1921.6.12 Diaphragms. Diaphragms used to resist prescribed lateral forces shall comply with the following: 1. Thickness shall not be less than 2 inches (51 mm). 2. When mechanical connectors are used to transfer forces benwveen the diaphragm and the lateral system, the anchorage Shall be adequate to develop 1.4 As fy where Ay is the connector $ cross-sectional area. 3. Collector and boundary elements in topping slabs placed ‘over precast floor and reof elements shall not be less than 3 inches (76 mm) 0 6 dy thick, where dis the diameter ofthe largest rein- {forcement in the topping slab. 4. Prestressing tendons shall nos be used as primary reinforce- ment in boundaries and collector elements of structural dia- ‘phragms. Precompression from wnbonded tendons may be used 10 resist laphragm forces. 1921.63 Wall piers. 1921.6.13.1 Wall piers not designed as par of «special momen resising fame shall hae transverse reinforcement designed 10 iui the veuirements in Section 1921 613.2 EXCEPTIONS: 1. Wal pers hats Seton 19217 ll perl wiv try whee le eo wall sept Peder capper! ote wa pr nd sheets eee tea ofa mae rf te sts ofl theyre 1921.6.182 Transverse enforcement shal be designed fo resis the shear forces determined from Sections 192145.1 and 1921 342. When the axial conpresive force incluling earth quake effects, less than Ay 120, transverse reinforcement in Mel piers may have standard hooks et each end in ew of hoe Spucing of iransvorse reinforcement shall not exceed inches £153 nn) Transverse retnforcement shall be extended beyond the (er cleo height ora Teast the developmen Tenth ofthe Targst Tongindival reinforcement in the wal pier 1921.6.13.3 Wall segments with horizontal lengih-to-thickness ratio less than 2p shall be designed as columns. 1921.7 Frame Members Not Part of the Lateral-force-resist- Ing System. 1921.7.1 Frame members assumed not to contribate to lateral resistance shall be detailed according to Section 1921.7.2 or 1921.73, depending on the magnitude of moments induced in those members when subjected to Ay, When induced moments under Jateral displacements are not caicalated, Section 1921,7.3 shall apply. 2103,CHAP. 19, DIV. I e172 ww2ia6s 1921.72 When the induced moments and shears under latecal displacements of Section 1921.7.1 combined with the factored gravily moments and shear louds do not exceed the design ‘moment and shear strength of the frame member, the following ‘conditions shall he satisfied. For this purpose, the load combina tions (L4D + 1.4L) and 0.9D shall be used. 1921,7.2,1 Members with factored gravity axial forces not exceeding (Agf’infaring sea or otherwise terminated oefetively transfer forces {othe restoring siel that designe ta desribute forces and avert suede local falar, may be utken as 085. Where edge distance is less than embedment length reduce oP. proportionately. For multiple edge distances less than embedment length, use multiple reductions. 1923.33 Design strength in shear. The design strength of ‘anchors ia shear shall be the minimum of Vox 0F © Ve where: Vig =0.75 Ap fr ‘and where loaded toward an edge greater than 10 diameters ava, toads, Ve = 0 800d For Sk: OV, = 65.4 by MP ‘or where loaded toward an edge equa to or less than 10 diameters Ve = 6 2nd? AVFe Ve = 0.106 gd? mF: where de equals the edge distance from the anchor axts to he free edge. For groups of anchors, the concrete design shear strength shall be takem asthe males! of 1. The design strength ofthe weakest anchor fies the number of anchors, 2. The desiga strengih of the row of anchors nearest the free edge in the direction of shear times the number of 08 or 43. The design strength ofthe row farthest from the fee edge in the direction of shear. For shear loading toward an ele equal oor les than 10 dam cers ana) or tension or shear not toward an edge less than five ‘dameters anes, reinforcing sufficient to carry the load shall be provided to prevent failure ofthe concrete in tension. Inno case ‘Shall the edge distance be less than four diameters. For1997 UNIFORM BUILDING CODE 1923.34 Combined tension and shear. When tension and shear ‘act simultaneously, all of the following shall be met: wie Hs [e"-"]) ey ee ee o2a.38 2109CHAP. 19, DIV. IV ‘toa 1924.2 1997 UNIFORM BUILDING CODE Division IV—DESIGN AND CONSTRUCTION STANDARD FOR SHOTCRETE SECTION 1924— SHOTCRETE 924 General. Shotcrete shall be defined as mortar or con- crete pneumatically projected at high velocity onto a surface. Ex- cept as specified in this section, shotcrete shall conform to the regulasions of this chapter for plain concrete or reinforced con- crete, 1924.2 Proportions and Materials. Shoterete proportions shall bbe selected that allow suitable placement procedures using the de- livery equipment selected and shall result in finished in-place hardened shoterete meeting the strength requirements ofthis code. 19243 Aggregate. Coarse aggregate, if used, shall not exceed 3ig inch (19 mm), 19244 Reinforcement, The maximum size of reinforcement shall be No. 5 bars waless U can he demonstrated by preconstruc- tion tests that adequate encasement of larger bars can be ‘achieved, When No, 5 or smaller bars are used, there shall be a minimum clearance between parallel reinforcement bars of 24 inches (64 mm). When bars larger than No. S are permitted, there shall be a minimum clearance between parallel bars equal to six diameters of the bars used. When two curtains of steel are pro- vided, the curtain nearest the nozzle shall have a minimum spac- ing equal to 12 bar diameters and the remaining curtain sell have ‘4 minimum spacing of six har diameters. EXCEPTION: Subject tothe approval ofthe bildng offi re tuced clearances may be used where it can be demonstrated by precon {trucion tes hat adequate encasement ofthe bars wed nthe design (an be achieved. Lap splices in reinforcing bars shall be by the noncontact lap splice method with at least 2 inches (51 mm) clearance between bars. The building official may permit the use of contact lap splices when necessary for the support ofthe reinforcing provided It can he demonstrated by means of preconstruction testing, that adequate encasement ofthe bars at the splice can be achieved, and provided that the splices are placed so that a line through the cen- ter of the nwo spliced bars is perpendicular to the surface of the shoterete work. ‘Shoterete shall not be applied to spirally tied columns, 192455 Preconstruction Tests. When reguired by the building offical ates pane shail be hos, cured, cored or sawn, examined land tested prior to commencement of the project. The sample pan el shall be represenative ofthe project and simulate job condi tions as casely as possible. The panel thickness and reinforcing Shall reproduce the thickest and most congested area specified in the structural design It shall be shot atthe same angle, using the same nozzleman and with the same concrete mix design that will besed on the project. 19746 Rebound. Any rebound or accumulated loose aggregate ‘shall be removed jrom the surfaces be covered prior to placing the inital or any succeeding layers ofshoterete. Rebound shall not be reused as aggregate 1924.7 Joints, Except where permitted herein, unfinished work ‘shall not be allowed to stand for more than 30 miuces unless al edges are sloped toa thn edge. Before placing additional materi- al adjacent to previously applied work, sloping and square edges Shall be cleaned and wetted. 19248 Damage. In-place shotcrete which exhibis sags. or sloughs, segregation, honeycombing sand pockets or other ob- vious defects shal be removed and replaced. Shrcrete above sags and sloughs shall be removed and replaced while sil plastic: 19249 Curing. During the curing periods specified herein, shoterete shall be maintained above 40°F (44°C) and in moist 2170 condition, In inital curing, showrete shall be kept cominuously ‘moist for 24 hours afer placement is complete. Final curing shall Continue for seven days afer shotereting, for three days if Iigh-early-strength cements used, or until the specified strength is obtained. Final curing shall consist ofa fog spray or an ap- proved moisture-retaining cover or membrane. In Sections of @ depth in excess of 12 inches (205 mam), final curing shall be the ‘same as that for inital curing, 1924.10 Strength Test. Strength test for shoteete shall be made by an approved agency on specimens which are representative of work ad which have been Water soaked for atleast 24 hours prior 4o testing, When the maximum size aggregate is larger than ig inch (9.5 mm), specimens shall consist of not less than three 3-inch-diameter (76 mm) cores or 3:inch (76 mi) cubes. When the ‘maximum size aggregate is“ inck (8.5 mm) or smaller, spect ‘mens shail consist of not less than three 2-inch-diameter (31 rim) ores or 2-inch (51 mm) cubes. Specimens shall be taken in ac- cordance with one ofthe following 1. From the in-place work: taken at least once each shift or less than one for each 50 cubic yards (38.2 m*) of shotcrete; or 2. From test panels: made not less than once each shift or not {ess than one fr each 50 cubie yards (38.2 me) of shorerete placed. When the maximum size aggregate is larger than 3g inch (9.5 min), the test panels shall have a minimum dimension of 18 inches by 18 inches (457 mm by 457 mm). When the maximum size aggre- gate is Is inch (9.5 mm) or smatter, the test panels shall have a ‘minima dimension of 12 inches by 12 inches (305 mre by 305 ‘min. Panes shall be gunned inthe same position as the work, dr- ing the course of the work and by nozzlepersons doing the work. The condttion under whick the panels ar cured shal be the same as the work, The average of three cores from a single panel shal be equal to ‘or exceed 0.85 f¢ with no single core less than 0.75 f. The aver- age of three cubes taken from a single panel must equal or exceed Fre with no individual cube less than O88. To check testing ac= ‘racy, locations represented by erratic cre strengths may be ret- ‘ested IA Inspections. 1924.11.1 During placement, When shotcrete is used for struc- tural members, a special inspector is required by Section 1701.5, Kent 12. The special inspector shall provide continuous inspection of the placement of the reinforcement and shotcreting and shall submit a statement indicating compliance with the plans and spec- fications. 1924112 Visual examination for structural soundness of in-place shotcrete. Completed shoterete work shail be checked visually for reinforcing har embedment, voids, rack pockets, sand streaks and similar deficiencies by examining @ minimum of three inch (76 mm) cores taken from three areas chosen by the design ‘engineer which represent the worst congestion of reinforcing bars ‘occurring in the project. Extra reinforcing bars may be added to rnoncongested areas and cores may be taken from these areas. The ‘cores shall be examined by the special inspector and a report sub ‘mitied to the building official prior to final approval ofthe shot- crete. EXCEPTION: Shotrete work ally supported om ea minor re: pais and when, 1 the opinion ofthe bul oficial, no spect ha ard ei 1924.12 Equipment. The equipment used in preconstruction testing shall be the same equipment used in the work requiring such testing, unless substitute equipment is approved by the build- ing official.1997 UNIFORM BUILDING CODE CHAP. 19, DIV, Vv "1925 19253 Division V—DESIGN STANDARD FOR REINFORCED GYPSUM CONCRETE SECTION 1925 — REINFORCED GYPSUM CONCRETE 1928.1 General, Reinforced gypsum concrete shall conform to UBC Standard 19-2. Reinforced gypsum concrete shall develop the minimum ulti- mate compressive strength in pounds per square inch (MPa) set forth in Table 19-E when dried to constant weight, with tests made ‘on cylinders 2 inches (51 mmm) in diameter and 4 inches (102 mm) long or on 2-inch (51 mn) cubes. For special inspection, see Section 170. 1925.2 Design. The minimum thickness of reinforced gypsum ‘concrete shall be 2 inches (51 mm) except the thickness may be re- duced to ly inches (38 mm), provided all ofthe following condi- tions are sauisfied: 1. The overall thickness, including the formboard, is not less than 2 inches (ST ran). 2. The clear span of the gypsum conerete between supports does not exceed 2 feet 9 inches (838 mm}. 3, Diaphragm action is not required. 4, The design live load does not exceed 40 pounds per square foot (195 kgint?). 1925.3 Stresses. The maximum allowable unit working stresses in reinforced gypsum concrete shall not exceed the values set forth in Table 19-F except as specified in Chapter 16, Bolt values shall not exceed those set forth in Table 19-G. Allowable shear in poured-in-place reinforced gypsum con- crete diaphragms using standard hot-rolied bulb tee subpurtins ‘shall be determined by UBC Standard 19-2. (See Table 19-2-A in the standard for values for commonly used roo} systems.) aanCHAP. 19, DIV. VE fo26 12832 1997 UNIFORM BUILDING CODE Division VI—ALTERNATE DESIGN METHOD SECTION 1926 — ALTERNATE DESIGN METHOD 1926.0 Notations. The following symbols and aotations apply only to the provisions ofthis sectio Ae 7088 area of section, square inches (mm?) loaded area. ‘Aa = maximum area of the portion ofthe supporting surface ‘hat is geometrically similar to and concentric with the loaded area azea of shear reinforcement within a distances, square inches (mm?) > = width of compression face of member, incis (mm). ty, = perimeter of critical seetion for slabs and footings, in ‘hes (eam). ‘web width, or diameter of citcuar section, inches (mm). distance from extremse compression fiber to centroid of tension renforeement, inches (wm) modulus of elasticity of eoncree, psi (MPa). See Section 1908.1 , = aodulus of elasticity of reinforcement, psi (MPa). See Section 1908.5.2 J’ = specified compressive strength of concrete, psi (Me). See Section 1905. = square root of specified compressive strength of con- crete, psi (MPa). fe = average spliting tensile strengih of lightweight ate concrete, psi (MPs). See Section 1905.1.4, permissible tensile stress in reinforcement, psi (MPa). specified yield strength of reinforcement, psi (MPa). esign moment. design axial load normal to cross section occurring si- rmulianeously with V; to be taken as positive for com- pression, negative for tension and to include effeets of tension due to creep and shrinkage. ‘modular ratio of elasticity. Balbo 5 = spacing of shear reinforcement in direction parallel to Tongitudinal reinforcement, inches (am), Y= design shear force at section. v= design sheur stress permissible shear stress caztied by concrete, psi (MPa). ‘permissible horizontal shear stress, psi (MPa). angle betswoen inclined sticrups and longitudinal axis of member. c= ratio of long side to short side of concentrated load or reaction area. ratio of tension reinforcement, As/bd. strength- reduction factor. See Section 1926.2.1. 1926.1 Scope. 1926.11 Nonprestressed reinforced concrete members shall be pertnitted to be designed using service loads (without load factors) and permissible service load stresses in accordance with provi sions of this section. 272 1926.1.2 For design of members not covered by this section, ap- propriate provisions of this code shall apply. 1926.13 All applicable provisions of this code for nonpres- tuessed concrete, except Section 1908.4, shall apply to members ‘designed by the alternate design method. 1926.14 Flexural members shall meet requirements for deflec- tion ‘control ia Section 1909.5 and requirements of Sections 191044 through 1910.7 of this code. 19262 General. 1926.2.1. Load factors ane strength-reduction factors shal! be taken as unity for members designed by the alterate design meth- od. 1926.2.2 It shall be permitted to proportion members for 75 per cent of capacities required by other parts ofthe section when con- sidering Wind or earthquake Forces combined with other loads, provided the resulting section is aot less thaa that required forthe ‘combination of dead and live load. 1926.2.3 When dead Joad reduces effects of other loads, bers shall be designed lor 89 percent of dead load in combination ‘with the other loads. 1926.3 Permissible Sorvice Load Stresses. 1926.3.L Siresses in concrete shall not exceed the Following: 1, Plexure. Extreme fiber stress in compression 045 fe 2. Shear Bearas and one-way slabs and footings: = Shear cattied by concrete, Yee. .seeeeeseeeees LAV (ForSk: 0.09 /F") ‘Maximum shear carried by concrete pus shear reinforcement (For mtd, + 0374F) soins ‘Shear carted by concrete, Ye see 124f (ears 030/755 asta aera eel ciao TRcaay ais md eto ‘Shear carried by concrete, vf wa 42RD FE [Fork (1 + 2/8008 /F] tout not greater than 2 Vf (ior St: 0.166 7%) 2 adele dade inal as {isto saforcemt provided, se Sections 1267.7 and 19267775 ‘een the supocing ste s wider onal ses an he onde area pe. Inkl bang tee cath oned re sl be permite fo be nerd by {AG/A, bt mot more han 2, When te supporting surface sloped or Sespei Ay de iad beak le ie eta ines fat oF fig oynmid or con contained wal wha he up and vn rupert he nde shag te oper ‘eral to 2 tonal 1926.32 Teasile stress in reinforcement f, shall not exceed the followin 1. Grade 40 or Grade 50 reinforcement... 20,000 pst (437.9 MPa)1997 UNIFORM BUILDING CODE 2. Grade 60 reinforcement or greater and welded wire fabric (smoothed or deformed) = 24,000 psi (165.5 MPa) 3, For flexural reinforcement, 3g inch (9.5 mm) or Tessin diameter, in one-way slabs of aot more than 12-foot (3658 mm) spea, but not greater than 30,000 psi (206.8 MPa) sesceees OSOf, 1926.4 Development and Splices of Reinforcement. 1926.4.1 Development and splices of reinforcement shall be #s required in Section 1912. 1926.4.2 in satisfying requirements of Section 1912.11.3, My stall be taken as computed moment capacity assuming all positive ‘moment tension reinforcement atthe section fo be stressed to the permissible tensile stress f, and Y, shall be taken as unfactored shear force atthe section. 1926.5 Flexure. For investigation of stresses at service 1 ‘straight-line theory (for flexure) shall be used with the fol assumptions: ing 1926.5.1 Strsins vary linearly as the distance from the neutral axis, except for deep flexural members with overall depth-span ta- tios greater than 2:5 for continuous spas aad 4:5 for simple spans, 4 nonlinear dsteibution of strain shall be considered. (See Section 1910.7.) 1926.5.2 Stress-stain relationship of concrete is a straight Line ‘under service loads within permissible service load stresses, 1926.53 In reinforced concrete members, concrete resists n0 ten- sion. 1926.4 It all be permitted to take the modular ratio, n = Ey/E, ‘asthe nearest whole number (but not less than 6). Except in caleu- lations for deflections, value of m for lightweight concrete shall be assumed to be the same as for normal-weight eonerele ofthe same strength 1926.85 In doubly reinforced flexural members, an effective modula ratio of 2 Fy/Be shell be used to transform compression reinforcement for stress computations, Compressive stress in such reinforcement shall not exceed permissible tensile stress. 1926.6 Compression Members with or without Flexure. 1926.6. Combined flexure and axial load capacity of compres sion members shall be taken as 40 percent ofthat computed in ac- ceontance with provisions in Section 1910, 1926.62 Slenderness effects shall be inchuled according to Te ‘quirements of Sections 1910.10 and 1910.11. In Formulas (10-7) and (10-8), the term P, shall be replaced by 2.5 times the design axial load, and @ shall be taken equal to 1.0. 1926.63 Walls shall be designed in accordance with Section 11014 with flexure and axial load capacities taken 2s 40 percent of that computed using Section 1914. In Formula (14-1, @ shall be (aken equal t0 1.0, 1926.7 Shear and Torsion. 1926.7.1. Design shear stress v shall be computed by: aa ba Where V is design shear force at section considered. 1926.72 When the reaction, in direction of applied shear, intro- duces Compression into the end regions of a member, scctions y (26-1) 1926748 located less than a distanced from face of support shall be pes- mitted tobe designed fort same shea vas that computed at distance 1926.73. Whenever applicable, effects of torsion, in accordance with provisions of Section 1911, shall be added. Shear and tor- Sional moment siengths provided by coneretcand limiting max hum stents for torsion shal be taken #855 percent of te values sven in Section 111, 1926.74 Shear stress carried by concrete. 1926.7.41 For members subjeet to shear and flexure oa, shear sizesscatied hy concrete ve shall not exceed 1.1.47 (For SI: 0.09 /F) unless a more detailed calculation is made in accor- dance wih Section 1926744. 1926.72 For members subject to axial compression, shear sires cartied by concrste vp shall not exceed 1A ff (Fer SI 0.09 Jf) unless « more detailed calculation is made in accord- ance with Section 1926-785. 1926.7.4.3 For members subject to significant axial tension, sear reinforcement shall be designed to carry total shear, unless 2 ‘more detailed calealation is made using, ue salt + ons) Fo 62) For Si v= 0001 + o00et) set Ws negative for tension. Oxanity Ny shal be expressed in psi (MPa). 1926744 For members sujet o shea an lexure ony ¥ i shal e permit fo computoby n= Fit 430 63) Forsk ye = 0088/7 4 99. ME Duty shall not exceed 1.9 /f'-(For SI: 0.16 yf"). Quantity Val shall not be taken greater than 1.0 whore fis design exoment o°- courting simultaneously with V at section considered 1926.74 For members subject to axial compression, ve may be computed by 7 a(t + 0.0006 x) Fe 6) Fors v, = 005(1 + comes #) ‘Quantity N/Ay shall be expressed in psi (MPs), 1926,7.4,6 Shear stresses cerried by concrete ¥. apply to nor- ‘mal-weight concrete, When lightweight agaregate concrete is ‘used, one of the following modifications shall apply: 1, When f; is specified and concrete is proportioned in acco ‘ance with Section 1904.2, £,/6.7 (For Sk: 1.8 f) shall be substi- tue foe's but the val of f6.7 (Por SE 1.8) shal ot exceed Vf. 2. When fi is not specified, the value of (Ff (For cvoss {7 sal be mulled by 0.5 for allightweigt oa: row andy OAS fo sand ghtwcightcovette. Lies nrpol Aion muy by applied when patil sand replacements ed 2473CHAP. 19, DIV. VI to67.47 6771.2 I. 1926.7.4.7 tn determining shcur siress by concrete, whenever applicable, elfects of axial tension due 0 creep and shrinkage in festrained members shall be included and it shall be permitted to include effects of inclined flexural compression in vatiable-depth rmombers. 1926.75 Shear stress carried by shear reinforcement. 1926.7..1 Types of shear reinforcement, Shear reinforcement shall consist ofthe following: 1. Stizrups perpendicular to axis of member. 2, Welded wire fabric with wires located perpendicular Wo axis ‘of member making an angle of 45 degrees or more with longitud nal tension reinforcement. 3. Longitudinal reinforcement with bent portion making, an angle of 30 degrees or moze with longitudinal fension reinforce- ‘ment 4, Combinations of stirrups and bent longitudinal reinforce ‘meat, S. Spirals. 1926.75. Design yield strength of shear reinforcement shall not ‘exceed 60,000 psi (413.7 MPa). 1926,7.5.3 Stirrups and other bars or wires used as shear 10 inforcement shall extend to a distance d from extreme compres- sion fiber and shall be anchored at both ends according to Section 1912.13 to develop design yield strength of reinforcement. 1926.7.5.4 Spacing limits for shear reinforcement. 1926.75.4.1 Spacing of shear reinforcement placod perpendicn lar to axis of member shall nol exceed d/2 o* 24 inches (610 mim). 1926.7.5.4.2 Inclined stirrups and bent longitudinal reinforee- ‘mont shall be so spaced that every 45-degree line, extending to- ward the reaction from middepth of member d/2 (o longitudinal {tension reinforcement, shall be erossed by at least one line of shear reinforcement, 1926.7.5.4.3 When (» — 1.) exceeds 2,/f", (For Sk: 0.156 yf.) ‘maximum spacing given by this subsection shall be reduced by ‘one half 1926.75.58 Minimum shear reinforcement. num axca of shear reinforcement shall be sign shear stress v is grcater than one half the permissible shear sess v, cartied by concrete, except the following: 1, Slab and footings. 2. Concrete joist construction defined by Section 1908.11 of this code, 3. Beams with total depth not greuter an 10 inches (254 mm), ‘wo and one-half times thickness of ange or ope half the width of ‘web, whichever is greater. 1926.75.52 Minimum shear reinforcement requitements of this section miay be waived if shown by test that required ultimate flex- ural and shear sirength can he developed when shear reinforct meat is omitted, 1926.75.53 Where shear reinforcement is required by this sub- section of by analysis, minimum area of shear reinforcement shall bbe computed by 6-5) Te 1997 UNIFORM BUILDING CODE bes For SI: A, = 034 & where by, and s are in inches (mi). 1926,75.6 Design of shear reinforcement. 1926.7.5.6.1. Where design shear sttess v exceeds shear stress carried by concrete b, shear reinforcement shall be provided in accordance with this Subsection. 1926.75.6.2 When shear reinforcement perpendicular to axis of member is used, (26-6) 1926.75.6.3 When inclined stlsrups are used as shear rein- forcement, vdOus FiGin a + cosa) 1926,7.8.6.4 When shear reinforcement consists of a single but fr a single group of parallel burs all bent up at the same dis- tance from the support, Ay (25-7) (26:8) where (v—¥) shall not exceed 1.6 /F (For Sk: 0.13 YF). 1926.75.65 When shear reinforcement consists of a series of ‘parallel bent-up bars or groups of parallel bent-up bars a different disnces from the support, required arca shall be computed by Fonnula (26-7), 1926.7.5.6.6 Only the center three fourths ofthe inclined portion ‘of any longitudinal beat bar shall be considered effective for shear reinforcement, 1926.75.6.7 When more than one type of shear reinforcement is used to reinfores the same portion of a member, required aren shall he computed as the sum of the various types separately. In such ‘computations, ve shall be included only once, 1926.7.5.6.8 Value of (v~ vz) shall not exceed 4.4,/F". (For Sit 037 Jf). 1926.7.6 Shear frietion, Where it is appropriate 1 consider shear tfausfer across a givea plane such as an existing or potential crack, an interface between dissimilar materials, or an interface between two concretes cast at different times, shear friction provi= sions of Section 1911,7 shall be permitted to bo applied with lit ‘ng maximum sttess for shear token as 55 perveat of that given in Section 1911.7.5. Permissible stress in shear friction reinforce- mnt shall be that given in Section 1926.3. 1926.7.7 Special provisions for slabs und footings. 1926.7.7.4 Shear capacity of slabs and footings inthe vicinity of ‘concentrated loads ot reactions is governed by the more severe of the following two conditions: 1926,7.7.1. Beam action for slab or footing with a critica sec- tion extending in a plane across the entire width and located at « distance d from face af concentrated load or reaction area. For this condition, the slab or footing shall be designed in accordance with Sections 1926.7.1 through 1926.7.5. 1926.7.7.1.2. Two-way ection for slab or footing with « critical seetion perpendicular to plane of slab and located so tat its perim- ter isa minimum but need not approach closer than d/2to petime- ter of concentrated load or reaction area. For this condition, the slab or footing shall be designed in accordance with Sections 1926.7.7.2 and 1926.7.7.3,1997 UNIFORM BUILDING CODE 1926,7.7.2 Desiss shear stress v shall be computed by v a (26-9) where Vand hy shall be taken at the critical section defined in Sec- tioa 1926.7.7.1.2. 1926.7.7.3 Design shear stress v shall not exceed v, given by For ‘mula (26-10) unless shear reinforcement is provided. ya (1 + ae (26-10) For Sk ye = 0088 ( + Be but ve shall not exceed 2,/f", (For St: 0.166 jf"). Be is the ratio (of long side to short side of concentrated load or reaction area. ‘When lightweight aggregate concrete is used, the modifications of Section 1926.7.4.6 shall apply. 1926.7.7.4 If shear reinforcement consisting of bars or wires is provided in accordance with Section 1911.12.3, v shall not exceed VF. (For Ski 0.083 77), and v shall not exceed 3,/F'- (Gor SI: 0.2577). 1926.7.1.8 1f shear reinforcement consisting of steel I or channel shapes (Gheatheads) is provided in accordance with Section 191.1244 of this code, onthe critical section defined in Section 1926,7.7.1.2 shall not exceed 3.5 Jf (For Sli 0.29 Jf.) and v on the eitical section define in Section 1911.12.47 shall not exceed 2 JF, (Por Sk: 0.166 yf. ). In Fonmulas (11-38) and (11-39), de~ sign sheat force V shall be multiplied by 2 and substituted for 1926.7.8 Special provisions for other members. For design of F e + 4. race oF suPPORT f+ ——— Face oF supront———+y 4 |, cenTen To CENTER SPAN -2 la CENTER TO CENTER SPAN-¢ ——w, 7 q Li q& EXTERIOR SUPPORT INTERIOR suPPORT EXTERIOR SUEPORT (No SUAS CONTINUITY) (CONTINUTEY PROVIDED) NORE FIGURE 19-1—MININUM EXTENSIONS FOR REINFORCEMENT IN SLABS WITHOUT BEAMS {See Section 1912.11.1 for reinforcement extension into supports.) 28a1997 UNIFORM BUILDING CODE 2101 21013 Chapter 21 MASONRY SECTION 2101 — GENERAL 2101.1 Scope. ‘The materials, design, construction and quality IF assurance of masonry shall be in accordance with this chapter 2101.2 Design Methods. Masonry stall comply with the provi- sions of one of the following desiga methods inthis chapter es well 1s the requirements of Sections 2101 through 2105. 2101.21 Working stress design. Masonry designed by the ‘warking stress design method shall comply with the provisions of Sections 2106 and 2107 2101.2.2 Strength design. Masonry designed by the strength

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