Allowable Bearing Capacity

It is the maximum pressure which may be applied to the soil such that the two fundamental requirements are satisfied Limiting the settlement to a tolerable amount. It is the net loading intensity at which neither the soil fails in shear nor there is excessive settlement which may be harmful for the structure

Preventing shear failure of soil

q_a = q_ult / FOS (With respect to shear)

FOS = 2.5