Q. A steel column of ISHB 350 @72.4 kg/m is subjected to a factored axial compressive load of 2000 kN. The load is transferred to a concrete pedestal of grade M20 through a square base plate. Consider bearing strength of concrete as 0.45fck, where fck is the characteristic strength of concrete. Using limit state method and neglecting the self weight of base plate and steel column, the length of a side of the base plate to be provided is
(A) 39 cm (B) 42 cm (C) 45 cm (D) 48 cm
Ans: 48 cm
Sol:
Given:
Factored load = 2000 kN, Bearing Capacity of concrete = 0.45 × 20 = 9
∴ Area required = 2000000/9 = 222222.222 mm2
Side of plate = √222222.222 = 471.40 mm = 47.1 cm
∴ A plate of 48 cm is to be provided.