Question

A built-up column 10 m long carries a service load of 720 kN. The column is restrained in position but not in rotation at both ends. If the design axial compressive stress for the column is 150 MPa, then the cross sectional area required will be _______$m{m}^2.$ [Use LSM]

Answer 1

$\because$ Service load,
$P=720kN$

$\therefore$ Factored axial load,
$P_u=1.5\times 720=1080kN$

Design axial compressive stress,
$f_{cd}=150MPa$

So, Area required
$=\frac{P_u}{f_{cd}}=\frac{1080\times {10}^3}{150}=7200m{m}^2$