Figure $1($a$)$ shows a floor layout at level $1$ of an office building, built in simple

conistruction. The loadings are given as follows

Loads from slab:

$($i$).$ Unfactored dead load including the selfweight of the slab $=4k\frac{N}{m^2}$

$($ii$).$ Unfactored imposed load

$=5k\frac{N}{m^2}$

$($iii$).$ Selfweight of secondary and main beams is assumed as $=0\mathrm{.}5k\frac{N}{m}$

Other loads:

$($iii$).$ Factored axial load from level $2$ and the upper stories $=300$kiv.

$($iv$).$ Unfactored wall load on all external beams $,=3kN{m}^2.$

With the height of the wall $=3\mathrm{.}5m.$

Column $\text{'}\frac{B}{1}/$ carries loads from beams $CA,CD$ and $CE.$ Column $\text{'}\frac{B}{1}\text{'}$ to be

designed is located between ground level to level $1.$ The column is $4m$ height and

has the section size of $254254$ UC $73$ in Grade S $275$ steel.

Based on the data given:

$($a$)$

Calculate the reaction forces for all beams at level $1,$ connected to solumn

$\text{'}$BN$\text{'}\frac{C}{b}ar(H)$

$($b$)$ Calculate the factored axial load and nominal moments carried by column

$\text{'}$Br$\text{'}$ from ground level to level $1.$

C$/1$

$($c$)$ Classify the section of column $\text{'}$BR$\text{'}$ CI$1$ c$/1$

$($d$)$ Carry out design check to ensure that the given size of column $\text{'}\frac{B}{1}\text{'}$ from

ground level to level $1$ is safe to carry the loads.

Use effective length of column in $x-x$ and $yy$ directions. $L_6=0\mathrm{.}85L$

$($e$)$ If the the column section is arranged as shown in Figure $1($c$),$ determine

whteher the sarne column size can carry the loads.