Finite Element Investigation of the Bearing Capacity of Square Footings Resting on Sloping Ground

Abstract

The ultimate bearing capacity of foundation placed on a slope is significantly affected by its vicinity to the slope face, which offers substantially lesser passive resistance as compared to a footing resting on a semi-infinite medium. Conventional bearing capacity theories fail to address the behavior of such foundations. Few existing theories predict the bearing capacity of foundations on slopes considering stress-based failure approach. However, deformation along the slope plays a major role in governing the failure of such foundations, thus requiring a coupled stress-deformation based failure analysis. With the aid of 3-D finite element modelling, employing coupled stress-deformation analysis, this study addresses the failure mechanism and the bearing capacity (q u ) of a square footing located on a dry cohesionless slope. The effect of various parameters, namely the angle of internal friction of soil, setback distance, slope inclination, footing width and the depth of embedment of the footing, have been investigated. Variations parameters are found to noticeably alter the bearing capacity estimate and the observed failure mechanism. A critical setback distance is obtained [(b/B)critical = 3] beyond which the failure mechanism resembles the same obtained for a footing resting on horizontal ground. The unit weight and modulus of elasticity of the soil material is found to have negligible effect on the bearing capacity.