e y5 oISION 2 Solutionathe LRFD load combinations per ASCE 7

e y5 oISION 2

a)the LRFD load combinations per ASCE 7 and corresponding loads in column are:

1) 1.4D

Load = 1.4*80=112 kips

2)1.2D+1.6L+0.5(Lr or S or R)

load = 1.2*80 + 1.6*40 +0.5*max(20,25,30)=1.2*80+1.6*40+0.5*30=175 kips

3)1.2D + 1.6(Lr or S or R) + (L or 0.5W)

load = 1.2*80+1.6*max(20,25,30)+max(40,0.5*22)=1.2*80+1.6*30+40=184 kips

4)1.2D + 1.0W + L + 0.5(Lr or S or R)

load = 1.2*80 + 22+40+0.5*max(20,25,30)=1.2*80+22+40+0.5*30=173 kips

5)0.9D + 1.0W

load = 0.9*80+22=94 kips

The controlling load combination is 1.2D + 1.6(Lr or S or R) + (L or 0.5W) and the corresponding load is 184 kips

b)the ASD load combinations per ASCE 7 and corresponding loads in column are:

1) D

Load = 1*80=80 kips

2)D+L

Load = 80+40=120 kips

3)D + (Lr or S or R)

load = 80+max(20,25,30)=80+30=110 kips

4)D + 0.75L + 0.75(Lr or S or R)

load = 80+0.75*40+0.75*max(20,25,30)=80+0.75*40+0.75*30=132.5 kips

5)D + (0.6W or 0.7E)

Load = 80+0.6*22 = 93.2 kips

6)D + 0.75L + 0.75(0.6W) + 0.75(Lr or S or R)

Load = 80+0.75*40+0.75*(0.6*22)+0.75*max(20,25,30) = 80+0.75*40+0.75*0.6*22+0.75*30 = 142.4 kips

7)0.6D + 0.6W

Load = 0.6*80+0.6*22=61.2 kips

The controlling load combination is D + 0.75L + 0.75(0.6W) + 0.75(Lr or S or R) and the corresponding load is 142.4 kips