Problem $3$

The $4-$story building shown below has a dead load $D=90psf,$ floor live load, $L=110psf.$ Both roof and floors have the same D and L loads. The length of columns is $24ft$ at the ground level and $12ft$ for all other floors. The column ends are pins $(Kx=Ky=1\mathrm{.}0)$ and $Lx=Ly$ for all columns

Determine Pu on interior columns B$2-4,$ B$2-1,$ and side column C$1-1$

Use Table $4-1$a $($p$.4-12$ to $4-24)$ in AISC to select the lightest W shapes for these columns

Use Table $4-4($p$.4-68$ to $4-83)$ in AISC to select lightest square HSS shape for the columns