Question

A stiff footing size 4.5x4.5m carries a total uniformly distributed load of 3250 kN. Find the intensity of vertical stress due to the loading at a point located at 4.5m below a corner of the footing. The central area of 3mx3m is loaded at twice the intensity of the remainder.

Answer 1

Stress below any point P inside footing will be calcuated from influence coefficients. Fadum charts to be referred from any standard text book (B.M.Das, Stress due to applied loads) for finding IN (Influence coefficient). Calculation for above problem are given in attached image below.

Total footing area will be divided in to four equal parts for calculations influence coefficient and then intensity of vertical stress.

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