$1.$ A $350$ mm diameter concrete column is to be reinforced with $16-25$mm vertical bars and $10$mmspiral. If fc $=28$ MPa, fy $=415$ MPa, and cover of $40$ mm$,$a$.$ Determine the design axial load.b$.$ Number of $25$mm vertical bars, $=0\mathrm{.}75$c$.$ Determine the maximum nominal axial strength of the designed column.d$.$ Determine the minimum spiral ratio for the design column section.e$.$ Determine the recommended pitch $($use an increment of $10$ mm$).$ Using NSCP CODE $2015$