Question

A square steel slab of area 1 m${}^2$ is provided for a column made of two rolled channel sections. The 300 mm x 300 mm column carries an axial compressive load of 2000 kN. The line of action of the load passes through the centroid of the column section as well as of the slab base. For plate take
$F_y=250N/m{m}^2$.
The required minimum thickness of the slab base is :

Answer 1

300 mm x 300 mm column leaves projection as



$a=b=\frac{1000-300}{2}=350mm$

$w=\frac{P_u}{A}=\frac{1.5\times 2000}{1\times 1}=3000kN/m^2=3N/m{m}^2$

$t_s={\left[\frac{2.5w(a^2-0.3b^2){\gamma }_{m0}}{F_y}\right]}^{1/2}>t_f$

$t_s={\left[\frac{2.5\times 3\times ({350}^2-0.3\times {350}^2)\times 1.1}{250}\right]}^{1/2}$

$\Rightarrow t_s=53mm$

$t\approx 55mm$