Question

A reinforced concrete square column (0.26m × 0.26m) is supported by a square isolated footing (spread footing). The footing is of plain concrete, and concentrically loaded. An engineer has suggested 1.25m × 1.25m footing. First, check the sufficiency of footing dimension. If it is not sufficient, design the footing in accordance with the requirements of ACI 318M-08 and using the following available data:

Net allowable soil pressure: net qa = 170 kPa

Column loads (unfactored): D = 160 kN L = 100 kN

Column steel: six No. 25 bars; fy = 420 MPa, Esteel = 200000 MPa

Column concrete: f 'c = 25 MPa

Footing concrete: f 'c = 20 MPa

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Answer 1