Q$4.$ A $400$ mm diameter column has an unsupported length of $3\mathrm{.}6$ m and it is braced against sideway at both the ends. The column is reinforced with $\backslash (6-16\backslash$phi $\backslash )$ bars which are tied spirally by $\backslash (6\backslash$bar$\{\backslash$phi$\}\backslash )$ bar at $28$ mm pitch $\backslash (\backslash$mathrm$\{$c$\}/\backslash$mathrm$\{$c$\}\backslash )$ with a clear cover of $40$ mm $.$ Determine the maximum compressive load that may be safely applied on this column. The grade of concrete is M$25$ and grade of steel is $\backslash (\backslash$mathrm$\{$Fe$\}-415\backslash ).$ and a spirally reinforced.