Calculate the maximum and minimum ASD and LRFD Load Combinat

Calculate the maximum and minimum ASD and LRFD Load Combinations for: A. D = 15k, E = +/-40k D = 24psi, Lr = 18psf, w = +/-45psf

A)For LRFD, Load combinations are

1) 1.4(D+F) =1.4*15 = 21k

2) 1.2(D+F+T)+1.6(L+H)+0.5(L_r or S or R) =1.2*15 =18k

3) 1.2D+1.6(L_r or S or R)+((0.5 or1.0)*L or 0.8W) = 1.2*15 =18k

4) 1.2D+1.6W+(0.5 or 1.0)*L+0.5(L_r or S or R) =1.2*15=18k

5) 1.2D+1.0E+(0.5 or 1.0)*L+0.2S =1.2*15+1.0*(+/-40) = 58k/-22k

6) 0.9D+1.6W+1.6H = 0.9*15 =13.5k

7) 0.9D+1.0E+1.6H =0.9*15+1.0*(+/-40)=53.5k/-26.5k

Therefore, minimum load combination = 13.5k and maximum load combination =58k

For ASD, Load combinations are

1) D+F =15k

2) D+H+F+L+T =15k

3) D+H+F+(L_r or S or R) =15k

4) D+H+F+0.75(L+T)+0.75(L_r or S or R) =15k

5) D+H+F+(W or 0.7E) =15+0.7*(+/-40) =43k/-13k

6) D+H+F+0.75(W or 0.7E)+0.75L+0.75(L_r or S or R) =15+0.75*(0.7*(+/-40))=36k/-6k

7) 0.6D+W+H =0.6*15 =9k

8) 0.6D+0.7E+H =0.6*15+0.7*(+/-40) =37k/-19k

Therefore, minimum load combination = -6k and maximum load combination =43k

B)For LRFD, Load combinations are

1) 1.4(D+F) =1.4*80. = 112psf

2) 1.2(D+F+T)+1.6(L+H)+0.5(L_r or S or R) =1.2*80+1.6*100+0.5*(20 or 28 or 14) =270psf(max)/263psf(min)

3) 1.2D+1.6(L_r or S or R)+((0.5 or1.0)*L or 0.8W)

= 1.2*80+1.6*(20 or 28 or14)+ (0.5or1.0)*100=240.8psf(max)/168.4psf(min)

4) 1.2D+1.6W+(0.5 or 1.0)*L+0.5(L_r or S or R)

=1.2*80+(0.5 or 1.0)*100+0.5*(20 or 28 or 14)=210psf(max)/153psf(min)

5) 1.2D+1.0E+(0.5 or 1.0)*L+0.2S =1.2*80+(0.5 or 1.0)*100+0.2*28 = 201.6psf(max)/151.6psf(min)

6) 0.9D+1.6W+1.6H =0.9*80 =72psf

7) 0.9D+1.0E+1.6H =0.9*80=72psf

Therefore, minimum load combination = 72psf and maximum load combination =270psf

For ASD, Load combinations are

1) D+F =80psf

2) D+H+F+L+T =80+100 =180psf

3) D+H+F+(L_r or S or R) =80+(20 or 28 or 14) = 108psf(max)/94psf(min)

4) D+H+F+0.75(L+T)+0.75(L_r or S or R) =80+0.75*100+0.75*(20 or 28 or 14) = 176psf(max)/165.5psf(min)

5) D+H+F+(W or 0.7E) =80psf

6) D+H+F+0.75(W or 0.7E)+0.75L+0.75(L_r or S or R) =80+0.75*100+0.75*(20 or 28 or 14) =176psf(max)/165.5(min)

7) 0.6D+W+H =0.6*80 =48psf

8) 0.6D+0.7E+H =0.6*80=48psf

Therefore, minimum load combination = 48psf and maximum load combination =176psf