PRE-FABRICATED STEEL STRUCTURE DESIGN TUTORIAL: PART 2

Live Load Calculation
According to BNBC 2006, page 10592, Table 6.2.4,  Live load (LL) is 1 KN/sq. m
A reduction can be done according to BNBC 2006, page 10597, Table 6.2.7
Tributary area for a frame
=6.1*12.18 sq. m
=74.30 sq. m
For this tributary area, the reduction factor, R is = 0.69
So, Live load is
=(0.69*1) KN/sq. m
=0.69 KN/sq. m
Applying bay spacing
=0.69*6.1 KN/m
=4.21 KN/m

Wind Load Calculation
According to BNBC 2006, page 10616, for this building,
L=12.18 m
B=18.29 m
h={4.570(Clear height)+0.5(Assumed rafter depth)+0.25(Purlin depth)} m
=5.32 m
So,
L/B=12.18/18.29=0.67
h/B=5.32/18.29=0.29
h/L=5.32/12.18=0.44
For a height 4.5 m where wind ward wall load is applied uniformly (see figure 1) ;[For a height 4.5 m wind ward wall load is always applied uniformly]
qz(4.5m)= CcC1CzVb² [Ref: BNBC 2006, page 10607]
Value of Cz = 0.368 for Exposure A
=47.2*10ˉ⁶*1*0.368*210²=0.77 KN/m²
For a height 5.32 m where wind ward wall load is applied trapezoidal (see figure 1)

Figure 1

qz(5.32m)= CcC1CzVb² [Ref: BNBC 2006, page 10607]
Value of Cz = 0.394 for Exposure A
=47.2*10ˉ⁶*1*0.394*210²=0.82 KN/m²

Force,
Wind ward wall, Pz(4.5 m)=CGCpeqz*Bay Spacing=1.654*0.8*0.77*6.1=6.22 KN/m
Wind ward wall, Pz(5.32 m)=CGCpeqz*Bay Spacing=1.620*0.8*0.82*6.1=6.48 KN/m
Wind ward roof, Pz=CGCpeqz*Bay Spacing=1.620*0.9*0.82*6.1=7.29 KN/m
Leeward roof, Pz=CGCpeqz*Bay Spacing=1.620*0.7*0.82*6.1=5.67 KN/m
Leeward wall, Pz=CGCpeqz*Bay Spacing=1.620*0.59*0.82*6.1=4.78 KN/m