A tied short column of square cross$-$ section is shown in the figure below, the column is

reinforced with $4-20$M longitudinal bars and $10$M ties. Use a $40$ mm clear cover to the ties. The

material properties are given below.

A$)$ Determine the factored moment $($Mr$)$ and the axial load resistance $($Pr$)$ at the balanced

condition

B$)$ Derive the column interaction diagram.

C$)$ Determine the factored moment capacity $($Mr$)$ for the pure bending condition $($P$=0).$

D$)$ If a factored axial load Pf $=200$ kN is applied to the column, determine the factored

moment resistance $($Mr$).$

E$)$ If the factored axial load is increased to Pf $=400$ kN$,$ determine, the factored moment

resistance $($Mr$).$

F$)$ Comment on the effect of the increase in the magnitude of axial load on the moment

resistance.