DESIGN PARAMETERS
STRAP BEAM - 1
PA - Factored = 314 kN Ultimate Load at Column/Footing A
PB - Factored = 387 kN Ultimate Load at Column Footing B
Ca = 0.35 m Column A Dimension
Cb = 0.35 m Column B Dimension
CA-B = XA-B = Z 5 m Distance from center of column A to center of column B
qa = 180 kPa Allowable Soil Bearing Capacity
Embedment = 1500 mm Depth of Excavation
Density, gs = 18 kN/m^3 Unit Weight of Soil
Concrete Density, gc = 24 kN/m^3 Density of Concrete
Trial "t" = 300 mm Trial Thickness of Footing
B= 1.75 m Width of Footing
Load Computations
PA - Service = 224.29 kN Serive Load at Column/Footing A
PB - Service = 276.43 kN Serive Load at Column Footing B
Ps Total = 500.71 kN Total Service Loads
Pu Total = 701.00 kN Total Factored Loads
Total Area Required of Footings
Arequied = Ps Total / qa = B x L = 4.00 m2 Required Area of Footings
L = L1 + L 2 = 2.29 m Total Length of Footing A and Footing B
Location of Resultant Pu from Column A
Pu Total XT = PAXA + PBXB
XT = (PAXA + PBXB)/ Pu Total 2.24 m Location of Resultant Pu from Column B
Computation of Required Dimensions
ATotal XT = FAXA + FBXB
ATotal XT = FAXA = BLAXA
ATotal XT = Constant 8.96 Constant
-0.5BCa-BZ = B -9.05625 B in Quadratic Equition
0.5B = A 0.875 A in Quadratic Equition
LA1 = 9.24
LA2 = 1.11
LA = 1.15 Length of Footing A
LB = 1.14 Length of Footing B
Geometric Coordinates of Strap Beam Footing
D1-2 0.35 m Distance from point 1-2
D2-3 0.8 m Distance from point 2-3
D3-4 3.455 m Distance from point 3-4
D4-5 0.395 m Distance from point 4-5
D5-6 0.35 m Distance from point 5-6
D6-7 0.395 m Distance from point 6-7
PLAN VIEW
LA = 1.15 LB = 1.14
1.75
1.75
0.35 0.35
PA - Factored = 314 ELEVATION VIEW PB - Factored = 387
PA - Service = 224.285714285714 PB - Service = 276.4286
XA-B
5
5 4.6
A 0.4 B
1 2 3 4 5 6 7
Distances 0.35 0.8 3.455 0.395 0.35 0.395
Footing 1.15 1.14
Length
-9.868 9.87
Net Soil Pressure
Qu = (PA+PB)/(Afooting) 174.92202 kPa Net soil pressure
Qu = (PA+PB)/(Afooting)*B 306.11354 kn/m Net soil pressure per meter
@ Point 1 Shear = 0 0.00 kN 0
@ Point A Shear = 0.175 53.57 kN 0
@ Point A Shear = 0.175 -270.30 kN 0
@ Point 3 Shear = 1.15 28.16 kN 0
@ Point 4 Shear = 4.605 28.16 kN 0
@ Point B Shear = 5.175 202.65 kN 0
@ Point B Shear = 5.175 -174.48 kN 0
@ Point 6 Shear = 5.745 0.00 kN 0
SHEAR DIAGRAM
202.65
53.57
28.16 28.16
0.00 0.00
-174.48
-270.30
Location of Max moment 0.883 From Column A
@ Point 1 Moment = 0 0.00 kN-m 0 0
@ Point A Moment = 0.175 4.69 kN-m 0.175 0
@ Max Moment = 1.058 -114.65 kN-m 0.175 0
@ Point 3 Shear = 1.15 -113.35 kN-m 1.15 0
@ Point 4 Shear = 4.605 -16.05 kN-m 4.605 0
@ Max Moment = 5.175 49.73 kN-m 5.175 0
@ Point 6 Shear = 5.745 0.00 kN-m 5.175 0
5.745 0
MOMENT DIAGRAM
49.73
0.004.69 0.00
-16.05
-113.35
-114.65
-16.05
-113.35
-114.65
Label STRB - 1
Analize and Design by : Engr. Marvin A. Bensig
Geometry and Loadings (Girder) Design Parameters
f'c = 20.7 Mpa
b= 0.2 m width of girder fy = 275 Mpa
h= 0.5 m height of girder Main ø = 16 mm
Stirrup ø = 10 mm Stirrup ø =
cc = 40 mm
DESIGN OF GIRDERS (FLEXURE) d= 442 mm
β= 0.85
Top Bars at Support
Mdemand = 114.65 kN-m Demand Moment At Support At Midspan
n= 7 pcs Assume number of bars
As = 1407.43350881 mm2 Total Area of Rebar S = 2 layers
a= 109.986989179 mm Depth of compression fiber d = 421.5 pcs 7 pcs
c= 129.396457858 a = 0.85c
fs = 1354.45844644 Mpa Actual Stress (fs must > fy) OK, Steel Yield
Actual T = 387.044214922 kN
cb = 289.028571429 mm "c" at balance condition S = 1 layer 3 pcs 3 pcs
ab = 245.674285714 mm "a" at balance condition d = 442
0.75ccb = 648.395858571 kN CC at Balance Condition Pass for Ductility
Mcapacity = 127.668800385 kN-m Beam Moment Capacity Pass for Flexure
Bottom Bars at Support Bottom Bars at Midspan
Mdemand = 49.73 kN-m Demand Moment Mdemand = 49.73 kN-m Demand Moment
n= 3 pcs Assume number of bars n= 3 pcs Assume number of bars
As = 603.185789489 mm 2
Total Area of Rebar As = 603.1858 mm 2
Total Area of Rebar
a= 47.1372810769 mm Depth of compression fiber a= 47.13728 mm Depth of compression fiber
c= 55.4556247963 a = 0.85c c= 55.45562 a = 0.85c
fs = 4182.20200339 Mpa Actual Stress (fs must > fy) OK, Steel Yield fs = 4182.202 Mpa Actual Stress (fs must > fy) OK, Steel Yield
Actual T = 165.87609211 kN Actual T = 165.8761 kN
cb = 303.085714286 mm "c" at balance condition cb = 303.0857 mm "c" at balance condition
ab = 257.622857143 mm "a" at balance condition ab = 257.6229 mm "a" at balance condition
0.75ccb = 679.931125714 kN CC at Balance Condition Pass for Ductility 0.75ccb = 679.9311 kN CC at Balance Condition Pass for Ductility
Mcapacity = 62.4669828512 kN-m Beam Moment Capacity Pass for Flexure Mcapacity = 62.46698 kN-m Beam Moment Capacity Pass for Flexure
Vu = 28.16 kN Shear Force generated based on Analysis
Vud < ØVn ØVn = Ø(Vc + Vs)
(f'c)^0.5*b*d = 383.54 kN
ØVc = Ø1/6(f'c)^0.5*b*d = 47.94 kN Factored Shear Capacity of Concrete
ØVc / 2 = 23.97 kN No need for Stirrups if this value is greater than Vu Notes: Stirrups is Needed
Vs = (Vu-ØVc)/Ø -26.37 kN Required Shear Strength for Stirrups
s = Avfyd/vs -569.87 mm Computed Spacing of Stirrups based on the Shear Required
Ø2/3(f'c)^0.5*b*d = 191.77 kN This value must be greater than Vs, to limit bursting and crushing of concrete
Ø2/3(f'c)^0.5*b*d is > Vs therefore, Section is Safe
1/3(f'c)^0.5*b*d = 127.85 kN If this value is greater than Vs, max spacing is S = d/2 s= 200 or 600mm
1/3(f'c)^0.5*b*d = 127.85 kN If this value is less than Vs, max spacing is S = d/4 s= 100 or 300mm
1/3(f'c)^0.5*b*d is > Vs therefore, max spacing of stirrups is = 200 mm
Additional Provisions for Eathquake Resistant Structure -Section 418
Actual width Minimum Width
Beam Dimension Limits =
200 > 250 Fail NSCP 418.6.2.1b
d/4 = 105.375 mm
Hoop Reinfocement at twice 6db = 96 mm
depth from the face of the support
= = 150 mm
governs = 90 mm
Stirrups Spacing
S1 = 200 Computed Spacing of Stirrups based on the Shear Required
S2 = 200 Maximum spacing of stirrups
S3 = 90 Hoop Reinforcement
governs (sh) = 90 mm
2h = 1000 Sh = 90 mm 11 pcs
3h = 1500 St = 150 mm 10 pcs
Schedule of Stirrups/Hoops : 1 @50mm, 11 pcs @ 90 mm, 10 pcs @ 150 mm, Rest @ 200 mm
STRUCTURAL ANALYSIS
DESIGN REPORT
Footing Name F2
Column Type Edge Footing
Design Paramters
f'c = 20 Mpa Strength of Concrete
fy = 275 Mpa Strength of Steel
Trial "t" = 300 mm Assume Thickness of Footing
Increment "t" = 25 mm Rounding off Interval
Minimum "L" = 800 mm Factored Column Load Concentric Footing
bar Ø= 16 mm bending reinforcement
Col-x = 350 mm size of column along x dir
Col-z = 350 mm size of column along z dir
REQUIRED DIMENSIONS
B = 1750 mm Dimension of Footing along Z Dir
L = 1150 mm Dimension of Footing along X Dir Wide Beam Shear
Final Area = 2012500 mm2 Actual Area of Footing
Qumax= 174.922 Kpa Net Soil Pressure
WIDE BEAM SHEAR øVc > Vu
øVc = ø(f'c)1/2Bd/6 Wide Beam Shear Formula
Effective, d1 = 166.83 mm Wide Beam Shear Effective Depth
t= 250 mm Wide Beam Shear Formula
Used t = 300 mm Wide Beam Shear Formula
Punching Shear
PUNCHING SHEAR CHECK
Used d = 217 mm
bo = 2268 mm Critical Length for Punching
Punching Area = 1691011 mm2
VuPunching = 295.7951 KN Punching Shear Force
ff'c bod/3 = 550.2471
1/2
KN Safe
Critical Area for Moment
FLEXURAL REINFORCEMENT REQUIREMENTS
d= 217 mm
Mu = 49.28 kN-m steel ratio, r = 0.0051
Rn = 1.011227 required As = 1933.27
rrqrd = 0.00379 number of bars = 9.62
rmin = 0.0051 say = 10.00 pcs - 16 mmf Both Ways
USE t = 300 mm
STRUCTURAL ANALYSIS
DESIGN REPORT
Footing Name Footing B
Column Type Center Footing
Design Paramters
f'c = 20 Mpa Strength of Concrete
fy = 275 Mpa Strength of Steel
Trial "t" = 300 mm Assume Thickness of Footing
Increment "t" = 25 mm Rounding off Interval
Minimum "L" = 1000 mm Factored Column Load Concentric Footing
bar Ø= 16 mm bending reinforcement
Col-x = 350 mm size of column along x dir
Col-z = 350 mm size of column along z dir
REQUIRED DIMENSIONS
B = 1750 mm Dimension of Footing along Z Dir
L = 1140 mm Dimension of Footing along X Dir Wide Beam Shear
Final Area = 1995000 mm2 Actual Area of Footing
Qumax= 174.922 Kpa Net Soil Pressure
WIDE BEAM SHEAR øVc > Vu
øVc = ø(f'c)1/2Bd/6 Wide Beam Shear Formula
Effective, d1 = 166.83 mm Wide Beam Shear Effective Depth
t= 250 mm Wide Beam Shear Formula
Used t = 300 mm Wide Beam Shear Formula
Punching Shear
PUNCHING SHEAR CHECK
Used d = 217 mm
bo = 2268 mm Critical Length for Punching
Punching Area = 1673511 mm2
VuPunching = 292.7339 KN Punching Shear Force
ff'c bod/3 = 550.2471
1/2
KN Safe
Critical Area for Moment
FLEXURAL REINFORCEMENT REQUIREMENTS
d= 217 mm
Mu = 48.86 kN-m steel ratio, r = 0.0051
Rn = 1.011227 required As = 1933.27
rrqrd = 0.00379 number of bars = 9.62
rmin = 0.0051 say = 10.00 pcs - 16 mmf Both Ways
USE t = 300 mm
