A $20320346$ UC column is to be used at ground floor in a multi$-$storey building. The column is to be pinned at the bottom and fixed at the top in both the $y-y$ and $z-z$ planes. The inter$-$storey height to be considered is $5\mathrm{.}75$ m $.$ The axial actions to be supported are as follows $-$

Permanent Action $=600kN$

Variable Action $=300kN$

You are required to check

I. the cross sectional resistance in compression

II$.$ buckling resistance of the column for the restraints given

$($a$)$ You are required to check buckling resistance of the column allowing for an additional mid$-$height tie in the z$-$z plane

Grade S$355$ steel is to be used.