Problem 4.28

 

Roof Loads

D = 3 k
Lr = 5 k

 

Floor Loads

D = 6 k
L = 10 k
W = 10 k

 

 

Load Combinations

 

ASCE 7
Equation		 IBC
Equation		 ASD Load Combination Load (kip) Shortest-
Duration Load		 CD Load / CD* (kip)
1 16-8 D + F 9 D 0.9 10
2 16-9 D + H + F + L + T 19 L 1.0 19
3 16-10 D + H + F + (Lr or S or R) 14 Lr 1.25 11.2
4 16-11 D + H + F + 0.75(L + T) + 0.75(Lr or S or R) 20.25 Lr 1.25 16.2
5 16-12 D + H + F + (W or 0.7E) 19 W 1.6 11.9
6 16-13 D + H + F + 0.75(W or 0.7E) + 0.75L + 0.75(Lr or S or R) 27.75 W 1.6 17.3
7 16-14 0.6D + W + H 15.4 W 1.6 9.6
8 16-15 0.6D + 0.7E + H 5.4 D 0.9 6

* See textbook section 4.24 for explanation/limitations of this shortcut.

 

NDS Table 2.3.2

 

Load Duration CD Typical Design Loads
permanent 0.9 dead load
ten years 1.0 occupancy live load
two months 1.15 snow load
seven days 1.25 construction load
ten minutes 1.6 wind/earthquake load
impact 2.0 impact load