Q$7$: Design a short spirally RC column $($using Interaction Diagram$)$ to support a factored axial load of $2220kN$ and a factored moment of $222kN.m($start with $D=50cm)$

$$ Use $10$ diameter for spiral and $25$ bars

$$ Use $F{c}^{\text{'}}=28$MPa$=4$ksi And $Fy=414$MPa$=60$ksi