Question $1$ :

The concrete $(\backslash (\backslash$boldsymbol$\{$E$\}\_\{\backslash$boldsymbol$\{$c$\}\}=\backslash$mathbf$\{30$ G P a$\}\backslash ))$ pier shown in figure below is reinforced using eight steel $(\backslash ($ E$\_\{$s$\}=\backslash$mathbf$\{200\}\backslash$mathbf$\{$G P a$\}\backslash ))$ reinforcing rods, each having a diameter of $20$ mm $.$ If the pier is subjected to an axial load of $1200$ kN through a rigid plate on top of it$,$ determine:

$($a$)$ The normal stress in the concrete and in the steel reinforcing rods.

$($b$)$ The shortening of the pier