A
REPORT
ON
STRUCTURAL ANALYSIS AND DESIGN OF
FACTORY
Prepared For
Prepared By
Roshan Kumar Kejariwal
Structural Engineer
Nec no-14859 civil A
Submitted To
TO WHOM IT MAY CONCERN
This report comprises the summary of the structural design of Commercial Building. The report consists
of design procedures adopted, assumptions made, and the input assign in the design. During design it is
assumed that the client will completely followed the architectural as well as the structural design. It is
also assumed that the construction will be supervised by a professional engineer.
The designer will not be responsible if any alteration or change to the structural system is made by the
client or contractor without the prior permission from the designer, or the alteration to the non-
structural system is made such that the weight of each individual floor or the weight of the whole
building is altered by more than 10% of the design weight of the floor and the total weight.
The design calculations and derivations are limited to only to let the concerned people know the
methodology adopted. However, the calculation may be provided to the client or the concerned
authorities when needed, upon request.
………………………….
(DESIGNER)
Introduction
General
This report presents the structure analysis and design of Truss Building. The building is Special Moment
Resisting Frame steel type of building. It is designed to meet both strength and serviceability
requirements when subjected to gravity and earthquake loads.
The analysis and design has been based on IS codes that are in practice in Nepal. This report consists of
the design assumptions, design methodology, design inputs and outputs, and sample design of
structural members.
Salient Features
Project Information
Type of building : Industrial
Location : Itahari
Building Features
The building has some special features which are listed below:
Type of Building : Steel Truss Building
Shape : Regular Rectangular Shape
Plinth level : As per architectural drawing
Roof floor Type : Inaccessible, Terrace
Walls : Brick walls on ground floor
Footing Type : Isolated footing
Depth of foundation : Min 5ft below ground level or as per site condition
6.09m (center to
Story Height :
center)
Total Height : 7.5m
No of Story : 1 storey
Figure 1: Modeling in Etabs
Load Calculation
Dead Load [IS875:1987 Pt.1]
GI Sheeting = 0.060 kN/m2
Fixings = 0.025 kN/m2
Services = 0.070 kN/m2
Total Load = 0.155 kN/m2
load on purlin = 0.140 kN/m
Imposed Load [IS875:1987 Pt.2]
Live Load = 0.71 kN/m2
load on purlin = 0.61 kN/m
Wind Load [IS875:1987 Pt.3]
Wind load F on a roof truss by static wind method is given by
F = (Cpe – Cpi) × A × pd
Where Cpe and Cpi are force coefficients for exterior and interior of the building.
Value of Cpi
Assume wall openings between
Then,
Cpi = ± 0.5
Value of Cpe
Roof angle, α = 11.80 ⁰
Height of the building to eaves = 6.10 m
Lesser dimension of the building in plan, w = 12.51 m
Building height to width ratio, h/w = 0.49
Here, ℎ
< 0.5
/
𝑤
Wind direction normal Wind direction
Roof to the ridge parallel to the ridge
h/w
Angle, α Windward Leeward Windward Leeward
side side side side
10 -1.2 -0.4 -0.8 -0.6
20 -0.5 -0.4 -0.7 -0.6
0.49
By interpolation,
11.80 -1.1 -0.4 -0.8 -0.6
Value of pd
Basic wind speed (Vb) = 47.00 m/s
Total height of building = 7.63 m
Design wind speed vz is given by
Vz = k1 × k2 × k3 × Vb
Here,
Risk Coefficient, k1 = 1.00
(Assuming the industrial building as general building and its
probable life about 50 years.)
Terrain, height, structure size factor, k2
Roof elevation = 6.096 m to 7.626 m
Terrain Category = Category 3
Greater dimension of the building in plan, L = 12.51 m
Structure Class = Class A
Height (m) Terrain category and class of building factor
4 m 1
For 7.626 m, k2 = 1.00
Topography factor, k3 (assume) = 1.00
Then,
Vz = k1 × k2 × k3 × Vb = 47.00 m/s
And,
Design wind pressure, Pd = 0.6 × Vz2 = 1.33 kN/m2
Wind Load on Roof Truss
Pressure Coefficent
(Cpe – Cpi)
Wind Cpe
Angle Wind Lee Cpi Wind Lee
ward ward ward ward
-1.1 -0.4 0.5 -1.6 -0.9
0
-0.5 -0.6 0.1
-0.8 -0.6 0.5 -1.3 -1.1
90
-0.5 -0.3 -0.1
windward Load on purlin = -1.94 kN/m
leeward Load on purlin -1.19 kn/m
TRUSS DESIGN
ETABS 2016 Steel Frame Design
IS 800:2007 Steel Section Check (Strength Summary)
Element Details (Part 1 of 2)
Level Element Unique Name Location (m) Combo Design Type Element Type Section
RISER C189 164 1.22857 UDStlS9 Column Special Moment Frame ISNB80M
Element Details (Part 2 of 2)
Classification Rolled
Class 1 Yes
Design Code Parameters
ɣM0 ɣM1 An /Ag LLRF PLLF Stress ratio Limit
1.1 1.25 1 1 0.75 0.95
Section Properties
A (m²) Izz (m⁴) rzz (m) Ze,zz (m³) Av,z (m²) Zp,zz (m³) Iyz (m⁴) It (m⁴)
0.0011 0.000001 0.03001 0.000022 0.0007 0.000022 0 0.000002
J (m⁴) Iyy (m⁴) ryy (m) Ze,yy (m³) Av,y (m²) Zp,yy (m³) Iw (m⁶) h (m)
0.000002 0.000001 0.03001 0.000022 0.0007 0.000022 0.0889
Material Properties
J (m⁴) Iyy (m⁴) ryy (m)
0.000002 0.000001 0.03001
E (kN/m²) fy (kN/m²) fu (kN/m²)
210000000 250000 410000
Stress Check Forces and Moments
Location (m) N (kN) Mzz (kN-m) Myy (kN-m) Vy (kN) Vz (kN) To (kN-m)
1.22857 -7.8995 0.1627 2.3922 -0.2738 -1.8416 0.1543
PMM Demand/Capacity (D/C) Ratio 9.3.1.1(ay)
D/C Ratio = My / Mndy
0.486 = 0.486
Basic Factors
Buckling Mode K Factor L Factor L Length (m) KL/r
Major (z-z) 1.133 0.921 1.22857 46.383
Major Braced 0.565 0.921 1.22857 23.112
Minor (y-y) 2.841 0.921 1.22857 116.322
Minor Braced 0.855 0.921 1.22857 34.986
LTB 2.841 0.921 1.22857 116.322
Axial Force Design
N Force Td Capacity Nd Capacity Pdy Capacity Pz Capacity Pd Capacity
kN kN kN kN kN kN
Axial -7.8995 243.1818 243.1818 117.486 224.0498 117.486
Tdg Tdn Ncr,T Ncr,TF An /Ag N /Nd
kN kN kN kN Unitless Unitless
243.1818 315.864 86423.1019 163.8998 1 0.032
Design Parameters for Axial Design
Curve α fcc (kN/m²) λ Φ χ fcd (kN/m²)
Major (z-z) a 0.21 963396.21 0.509 0.662 0.921 209392.33
MajorB (z-z) a 0.21 3880171.54 0.254 0.538 0.988 224561.58
Minor (y-y) a 0.21 153177.4 1.278 1.429 0.483 109799.98
MinorB (y-y) a 0.21 1693246.13 0.384 0.593 0.957 109799.98
Torsional TF a 0.21 153177.4 1.278 1.429 0.483 109799.98
Moment Designs
M Moment Mspan Moment Md(yield) Capacity Mdv Capacity Mnd Capacity Md(LTB) Capacity
kN-m kN-m kN-m kN-m kN-m kN-m
Major (z-z) 0.1627 0.1627 4.9273 4.9273 4.9273 4.9273
Minor (y-y) 2.3922 2.3922 4.9273 4.9273 4.9273
Curve αLT λLT ΦLT χLT C1 Mcr (kN-m)
LTB a 0.21 0.112 0.497 1 2.7 431.2602
Cmy Cmz CmLT kz ky KLT My / Mdy Mz / Mdz α1 α2
Factors 0.622 0.4 0.4 1.002 1.006 0.997 0.486 0.033 2 2
Shear Design
V Force (kN) Vd Capacity (kN) To Capacity (kN-m) Stress Ratio Status Check
Major (y) 0.2738 89.3821 0.1543 0.003 OK
V Force (kN) Vd Capacity (kN) To Capacity (kN-m) Stress Ratio Status Check
Minor (z) 1.8416 89.3821 0.1543 0.021 OK
Shear Design
Vp (kN) kv (Unitless) ΛW (Unitless) Τb (kN/m²)
Reduction 89.3821 0 0 1
Column Details:
ETABS 2016 Steel Frame Design
IS 800:2007 Steel Section Check (Strength Summary)
Element Details (Part 1 of 2)
Level Element Unique Name Location (m) Combo Design Type Element Type Section
ROOR C174 61 3.72336 UDStlS9 Column Special Moment Frame 2ISMC 250
Element Details (Part 2 of 2)
Classification Rolled
Class 3 No
Design Code Parameters
ɣM0 ɣM1 An /Ag LLRF PLLF Stress ratio Limit
1.1 1.25 1 1 0.75 0.95
Section Properties
A (m²) Izz (m⁴) rzz (m) Ze,zz (m³) Av,z (m²) Zp,zz (m³) Iyz (m⁴) It (m⁴)
0.0077 0.000076 0.09927 0.000608 0.0077 0.000709 0 3.274E-07
J (m⁴) Iyy (m⁴) ryy (m) Ze,yy (m³) Av,y (m²) Zp,yy (m³) Iw (m⁶) h (m)
3.274E-07 0.000067 0.09355 0.000586 0.0035 0.000694 0.25
Material Properties
J (m⁴) Iyy (m⁴) ryy (m)
3.274E-07 0.000067 0.09355
E (kN/m²) fy (kN/m²) fu (kN/m²)
210000000 250000 410000
Stress Check Forces and Moments
Location (m) N (kN) Mzz (kN-m) Myy (kN-m) Vy (kN) Vz (kN) To (kN-m)
3.72336 48.1321 39.4915 3.2191 -18.2898 -1.3918 0.0018
PMM Demand/Capacity (D/C) Ratio 9.3.2.2(a)
D/C Ratio = P / Pdy + Ky * Cmy * (My,span / Mdy; ) + KLT *
(Mz,span / Mdz; )
0.423 = 0 + 0.029 + 0.394
Basic Factors
Buckling Mode K Factor L Factor L Length (m) KL/r
Major (z-z) 2.037 0.873 3.72336 76.414
Major Braced 0.779 0.873 3.72336 29.216
Minor (y-y) 2.391 0.973 4.1529 106.161
Minor Braced 0.807 0.973 4.1529 35.847
LTB 2.391 0.973 4.1529 106.161
Axial Force Design
N Force Td Capacity Nd Capacity Pdy Capacity Pz Capacity Pd Capacity
kN kN kN kN kN kN
Axial 48.1321 1751.3455 1751.3455 788.7107 1116.572 788.7107
Tdg Tdn Ncr,T Ncr,TF An /Ag N /Nd
kN kN kN kN Unitless Unitless
1751.3455 2274.7876 1421.1508 1417.1415 1 0.027
Design Parameters for Axial Design
Curve α fcc (kN/m²) λ Φ χ fcd (kN/m²)
Major (z-z) c 0.49 354955.84 0.839 1.009 0.638 144897.95
MajorB (z-z) c 0.49 2428133.83 0.321 0.581 0.938 213288.88
Minor (y-y) c 0.49 183902.96 1.166 1.416 0.45 102351.27
MinorB (y-y) c 0.49 1612952.2 0.394 0.625 0.901 102351.27
Torsional TF c 0.49 183902.96 1.166 1.416 0.45 102351.27
Moment Designs
M Moment Mspan Moment Md(yield) Capacity Mdv Capacity Mnd Capacity Md(LTB) Capacity
kN-m kN-m kN-m kN-m kN-m kN-m
Major (z-z) 39.4915 39.4915 138.0735 138.0735 138.0735 100.1134
Minor (y-y) 3.2191 3.8169 133.2739 133.2739 133.2739
Curve αLT λLT ΦLT χLT C1 Mcr (kN-m)
LTB c 0.49 0.699 0.867 0.725 1.604 310.5118
Cmy Cmz CmLT kz ky KLT My / Mdy Mz / Mdz α1 α2
Factors 1 1 1 1 1 1 0.024 0.286 2 2
Shear Design
V Force (kN) Vd Capacity (kN) To Capacity (kN-m) Stress Ratio Status Check
Major (y) 18.2898 462.8115 0.0018 0.04 OK
Minor (z) 1.3918 1011.1393 0.0018 0.001 OK
Shear Design
Vp (kN) kv (Unitless) ΛW (Unitless) Τb (kN/m²)
Reduction 462.8115 0 0 1
BASE PLATE AND ANCHOR BOLT DESIGN
CHECK FOR SIZE OF BASE PLATE C1
Axial Load P 109.0 kN
Factored Moment about X-axis, Mpx 100.0 kNm
Factored Moment about Z-axis, Mpz 0.0 kNm
Horizontal Force along X- axis , Fx 40.0 kN
Horizontal Force along Z- axis , Fz 0.0 kN
Length of base plate along X-axis,
450 mm
Lbp
Width of base plate along Z- axis,
350 mm
Bpb
Depth of column along X-axis , Dx 400 mm
Depth of column along Z-axis , Dz 300 mm
Distance betn. edge of base pl.& cl. of bolt, ed 75 mm
N/m
Ultimate stress of bolt in tension stf 470
m2
N/m
Yield stress of bolt fyb 295
m2
N/m
Characteristic compressive strength of concrete,fck 25
m2
N/m
Permissible stress in conc. in bearing, scc 42.52
m2
No Increase in permissible stress in LSD 1
N/m
Max Bearing Pressure, smax =P/A+6xMx/(Lbp2 x Bbp )+6xMz/(Lbp x Bbp2) 11.53
m2
N/m
Min Bearing Pressure, smin =P/A-6xMx/(Lbp2 x Bbp )-6xMz/(Lbp x Bbp2) -10.14
m2
Remarks Base Plate Size is O.K.
DESIGN OF BOLT
Calculation of bolt along Z- axis
Axial force, P 109.0 kN
Moment about X-axis, Mx 100.0 kNm
Moment about Z-axis, Mz 0.0 kNm
Horizontal Force along X- axis , Fx 40.0 kN
Horizontal Force along Z- axis , Fz 0.0 kN
N/m
Max Bearing Pressure, smax =P/A+6xMx/(Lbp x Bbp2 ) 0.77
m2
N/m
Min Bearing Pressure, smin =P/A-6xMx/(Lbp x Bbp2 ) 0.63
m2
Distance Y1 = smax x Bpb/ (smax + smin) 192.50 mm
Distance betn. cl. of base pl. & cg. of comp. Force,
Not reqd. mm
Y 2 = B / 2 - Y1 / 3
Lever arm, Y3 = Bpb - ed - Y1 / 3 Not reqd. mm
Tension (Taking moment about Compression line)
No tension kN
T=((Mx+Fzxt - P x Y2) / Y3
provide nominal
Remarks
bolt
Dia of bolt 20 mm
Gross area provided 315 mm2
Net area provided 252 mm2
Tensile capacity of each bolt based on tensile strength 84477 N
Tensile capacity of each bolt based on concrete break out failure 1591819 N
So, Effective Tensile capacity 84477 N
No. of bolt per side 2.00 nos
Shee
2 X 660MW LANCO VIDARBHA TPP LITL-008-CVE-104-R- t
REV B
0101 #RE
Design of UCB
F!
LENGTH OF BOLT
Length of bolt provided 750 mm
DESIGN OF STIFFNER PLATE
The stiffner palte is first checked against local buckling assuming a 20 mm thick
stiffner palte
Fy 325 N/mm2 Ts 20 mm
Gusset outstand
Outstand length 250 mm
D/Ts 12.5 < 11.93
238.5
Average height of the stiffner plate should be less than mm
6
Smaller height 200 mm
Higher height 200 mm
238.5
So average height 200 mm < mm OK
6
The stiffner is semi compact section
distace between flange to edge of base plate 150 mm
distance between stiffner plate 188 mm
194197. 194.2
The shear on the stiffner plate N KN
3 0
Shear capacity 682323 N 682.3 kN OK
0.6*Vd 409.39 > 194.20 KN
So the moment capacity will not get reduced by the effect of shear.
Bending moment 17838514 Nmm 17.84 KNm
Bending capacity 39393939 Nmm 39.39 KNm OK
Hence the size of the stiffenr plate is
satisfactory.
Weld connecting column-gusset-base plate
Load on weld 54.50 KN
Weld
Assuming an 6 mm weld 10 mm
size
Length of the weld 3276 mm
Load per mm 0.02 kN/mm
1519.5
Weld capacity 1.52 kN/mm OK
9
Thickness of the base plate
Three sides fixed
Thickness of the base plate 25 mm
for stiffner plate connected to flange
Plate dimension (three edge fixed) a 188 b 150
-
cofficient from roarks book beta 3 0.1961333
3
From Roark's chart (Table 11.4) 1.2533333
-81.411 N/mm2 a/b
stress 33
Strength of the base plate 354.55 N/mm2 OK
for stiffner plate connected to web
Plate dimension (three edge fixed) a 169 b 175
cofficient from roarks book beta 3 0.317 a/b 0.97
From Roark's chart (Table 179.014
Stress N/mm2
11.4) 8
Strength of the base plate 354.55 N/mm2 OK
54705.
Shear capacity of Bolt N 54.71 KN
09
when the bolts will be in compression, they will be eefective in shear
Total capacity 109.41 KN > 40 OK
Bolt subjected to cobined shear and tension
Factored shear force acting on the
Vsb 0.00 kN
bolt
Vdb Design shear capacity 54.71 kN
Factored tensile force acting on
Tb 2.00 kN
the bolt
Design tension
Tdb 84.48 kN
capacity
So, Interaction ratio 0.00 < 1 OK
Design of
Footing
Direct Load from pedestal, W1 = 129.80 kN
Moment from pedestal = 0.00 kNm
Try a
1.82 x 1.82 x 0.30 m
footing:
Weight of footing, W2 = 24.843 kN
Weight of soil above footing, 68.0918
= kN
W3 4
Then,
Total Vertical Load = 222.73 kN
Overturning
= 0.00 kNm
Moment
Eccentricity of resultant vertical force = 0.00 m < 𝑏 = 0.30 m
/
Therefor
6
e,
Base pressure distribution is triangular with no part in tension.
Width of footing in contact with soil = 1.82 m
Now,
Maximum pressure kN/m 1.25 x kN/m
67.24 2 < 2 = 150 kN/m2 OK
= 120
Pressure ordinate at the face of
= 67.24 kN/m2
pedestal
Downward pressure due to self-weight of soil and concrete = 29.1 kN/m2
Then,
Length of foundation slab off the face of pedestal = 0.71 m
Factored BM about the face of kNm/
= 14.42
pedestal m
Diameter of bars = 12 mm
Clear Cover = 75 mm
Effective depth required = 73.63 mm
Effective depth
= 219 mm OK
provided
Area of steel
= 263 mm2
required
(checked against minimum reinforcement 0.12
)
of %
Spacing
= 430 mm
required
Spacing
= 150 mm
provided
Provide 12 mm dia bars @ 150 mm c/c on top and bottom both ways.
Check for Punching Shear
Vertical Load as of Load Combo I = 110.00 kN
Area resisting punching
= 147000 mm2
shear
Punching shear stress N/mm
= 0.75 2
developed
Permissible shear stress = 1.12 N/mm2 OK
No shear reinforcement is needed.
References
NBC Nepal Building Code
IS 800:1998
Limit State Design of Substructure- Swamisharan
ETABS manual V 16
