PROJECT : PROPOSED WARE HOUSE AT NIGERIA

ENGINEER : C

3.7 m
D
B

6m

A 11 m E

1 Building Dscription L B H (eave) Bay spacing ridge (rh)

m m m m m
20.136 11 6 4.977 3.7

2 Load Data

a DL (dead load of given as) 0.4 kn/m2

dead load/m run after on 1.99 kn/m

b LL (live load given as 0.75 kn/m2

liveload/m on rafter 3.73 kn/m

c WL (wind load)

Design wind pressure = Pd = Ka x Kc x Kd x Pz

Ka 0.9 Tributary Area 29.862 m2

If Tributary Area <= 10 than 1
If Tributary Area = 25 than 0.9
If Tributary Area >= 100 than 0.8
Kc 0.9 When Roof is subjected to Pressure & sucction Both (Applicable for Most building)
Kd 0.9 When Building Shape is (Square, Rectangular, Triangular)

Design wind speed = Vz = K1 x K2 x K3 x Vb

From IS 875 (PART-3)
K1 1.0 Risk Coefficient + Assuming 50 years of design life)
K2 1.0 Terrain Category (2) From table 2.8 , Class-A ; IS 875 (PART 3)
K3 1.0 Topography Factor
K4 1.0 Cyclonic Region (For East Coast & West Cost up to 60 Km 1.15)
Assuming the building situated at Nigeria the Basic Wind speed 47 m/sec

Design wind speed Vz = 47 m/sec

Design wind speed Pz = 0.6 x Vz2

1325.40 N/m2
1.3 kn/m2
Design Wind Pressure Pd = 1.0 kn/m2

wind load on individual surface .

The wind load WL = (Cpe-Cpi) A x Pd

a Internal Pressure Coefficient 90°

Assuming building with low degree perveability C

Cpi = ± 0.2

3 External pressure coefficient

0° B
External pressure coefficient for walls and roof are tabulated in( table 1a) A

Calculation of total wind load

h/w 0.55
l/w 1.83
Exposed area of wall per frame @ 4.977 m c/c D
270°
is A= 29.862 m2

wind load on wall / frame, (A x Pd) = 28.9 kn

 Table 1a the value of cpe will be taken from IS 1893 (part 3)

Angle Cpe Cpi Cp=(Cpe - Cpi) Total Wind kn

(Cp x A x Pd)
Ø wind ward lee ward wind ward lee ward wind ward
A B C D A B C D A
0.2 0.5 -0.45 -0.8 -0.8 14.43
0° 0.7 -0.25 -0.6 -0.6
-0.2 0.9 -0.05 -0.4 -0.4 25.97
0.2 -0.7 -0.7 0.5 -0.3 -20.20
90° -0.5 -0.5 0.7 -0.1
-0.2 -0.3 -0.3 0.9 0.1 -8.66

For Roof
A = bay spacing x sqrt[(b)2+(rh)2] Roof angle Ø = tan -1

A= 57.76 m2

A.pd = 76.56 kn

Table 1b the value of cpe will be taken from IS 1893 (part 3)

Angle Cpe Cpi Cpe - Cpi Total Wind kn (Cpe

- Cpi) .A.Pd
wind ward
Ø EF lee ward GH wind ward lee ward wind ward
0.2 -0.71545232 -0.61643032 -54.77
0° -0.5155 -0.416430318
-0.2 -0.31545232 -0.21643032 -24.15
EG FH
0.2 -0.95530562 -0.72410758 -73.13
90° -0.755305623 -0.524107579
-0.2 -0.55530562 -0.32410758 -42.51

Dead Load :- Replacing the distribution DL of 1.99 kn/m on rafter by equivalent concentrated load at
two intermediate points corresponding at purlin locations one each rafter

DL WD = 3.66 kn

Live Load WL = 6.87 kn

w
w w
w C w
w/2 w/2

B 11 m D

LOAD DIAGRAM RIGID FRAME

w/2
w/2 w/2
w/2 C w/2
w/2 w/2

B 11 m D

LOAD DIAGRAM ENDWALL FRAME

1/3 breadth (b)
m
11
 Total Wind kn UDL Wind kn/m2
(Cp x A x Pd) Member Load
lee ward wind ward lee ward (+ Means Towards the structure)
B C D A B C D (- Means Away froms the structure)
-12.98 -23.08 -23.08 2.40 -2.16 -3.85 -3.85
-1.44 -11.54 -11.54 4.33 -0.24 -1.92 -1.92
-20.20 14.43 -8.66 -3.37 -3.37 2.40 -1.44
-8.66 25.97 2.89 -1.44 -1.44 4.33 0.48

0.33636364 18°
so value interpolate between 10-20 degree

UDL Wind kn/m2

Total Wind kn (Cpe
- Cpi) .A.Pd Member Load

wind ward lee ward

lee ward (EF) (GH)
-47.19 -4.98 -4.29
-16.57 -2.20 -1.51
EG FH
-55.44 -6.65 -5.04
-24.81 -3.86 -2.26

WIND LOAD APPLY

C
A
EF
GH

D B

When Angle 0 degree

EF GH

When Angle 90 degree

EG EG

When Angle 270 degree

FH FH

Generally it is not Governing

Cpe
Degree EF GH EG FH
0 -0.8 -0.4 -0.8 -0.4
5 -0.9 -0.4 -0.8 -0.4
10 -1.2 -0.4 -0.8 -0.6
20 -0.4 -0.4 -0.7 -0.6
30 0 -0.4 -0.7 -0.6
45 0.3 -0.5 -0.7 -0.6
60 0.7 -0.5 -0.7 -0.6

Degree
18 -0.56
-0.5155
-0.515452 -0.41643 -0.755306 -0.524108
TABLE-4 (AS PER IS 875 PART-3 ) Cpe for Wall
Building Height Building Plan Elevation Wind Cpe for Surface
Plan
ratio Ratio Angle Ø A B C D
1<l/w<3/2 0 0.7 -0.2 -0.5 -0.5
90 -0.5 -0.5 0.7 -0.2
h/w<1/2
3/2<l/w<4 0 0.7 -0.25 -0.6 -0.6
90 -0.5 -0.5 0.7 -0.1
1<l/w<3/2 0 0.7 -0.25 -0.6 -0.6
90 -0.6 -0.6 0.7 -0.25
1/2<h/w<3/2
3/2<l/w<4 0 0.7 -0.3 -0.7 -0.7
90 -0.5 -0.5 0.7 -0.1
1<l/w<3/2 0 0.8 -0.25 -0.8 -0.8
90 -0.8 -0.8 0.8 -0.25
3/2<h/w<6
3/2<l/w<4 0 0.7 -0.4 -0.7 -0.7
90 -0.5 -0.5 0.8 -0.1
l/w=3/2 0 0.8 -0.25 -0.8 -0.8
90 -0.8 -0.8 0.8 -0.25
h/w>ᴔ
l/w=1 0 0.7 -0.4 -0.7 -0.7
90 -0.5 -0.5 0.8 -0.1
l/w=2 0 0.7 -0.4 -0.7 -0.7
90 -0.5 -0.5 0.8 -0.1

TABLE-5 (AS PER IS 875 PART-3 ) Cpe for Pitched Roof h/w<=0.5
Building Height Roof Angle ᾱ Wind Angle Ø= 0˚ Wind Angle Ø= 90˚ ROOF 2.862
Ratio ANGLE
degree EF GH EG FH 0 -0.8
0 -0.8 -0.4 -0.8 -0.4 5 -0.9
5 -0.9 -0.4 -0.8 -0.4 0 -0.4
h/w<= 1/2 10 -1.2 -0.4 -0.8 -0.6 5 -0.4
20 -0.4 -0.4 -0.7 -0.6 0 -0.8
30 0 -0.4 -0.7 -0.6 5 -0.8
45 0.3 -0.5 -0.7 -0.6 0 -0.4
60 0.7 -0.6 -0.7 -0.6 5 -0.4
0 -0.8 -0.6 -1 -0.6
5 -0.9 -0.6 -0.9 -0.6
1/2<h/w<=3/2 10 -1.1 -0.6 -0.8 -0.6
20 -0.7 -0.5 -0.8 -0.6
30 -0.2 -0.5 -0.8 -0.8
45 0.2 -0.5 -0.8 -0.8
60 0.6 -0.5 -0.8 -0.8
0 -0.7 -0.6 -0.9 -0.7
5 -0.7 -0.6 -0.8 -0.8
3/2<h/w<6 10 -0.7 -0.6 -0.8 -0.8
20 -0.8 -0.6 -0.8 -0.8
30 -1 -0.5 -0.8 -0.7
40 -0.2 -0.5 -0.8 -0.7
50 0.2 -0.5 -0.8 -0.7
60 0.5 -0.5 -0.8 -0.7
 local Cpe
0.25w

-0.8

-1

-1.1

-1.1

-1.2

-1.2

-1.25

-1.25

-1.25

h/w<=0.5 1/2<h/w<=3/2 3/2<h/w<6

-0.857248 -0.8 -0.857248 -0.7 -0.7

-0.9 -0.7
-0.4 -0.6 -0.6 -0.6 -0.6
-0.6 -0.6
-0.8 -1 -0.942752 -0.9 -0.842752
-0.9 -0.8
-0.4 -0.6 -0.6 -0.7 -0.757248
-0.6 -0.8