BEARING CAPACITY ESTIMATION OF STRIP FOOTING ON TWO-LAYERED c-ϕ SOILS BASED ON THE RIGID PLASTIC FINITE ELEMENT METHOD

Abstract

This study investigates the bearing capacity of a strip footing on two-layered c-ϕ soils by considering layer factors estimated using an in-house FEM code, namely, the rigid-plastic finite element method. The influences of the following ratios on the bearing capacity factors were investigated: the ratio of the tangent of the angle of friction of the bottom layer to that of the top layer; the ratio of the cohesion of the bottom layer to that of the top layer; the ratio of the unit weight of the bottom layer to that of the top layer; and the ratios of the embedment of the footing and the thickness of the top layer to the footing width. Based on the influences of those ratios, layer factors are determined. Several types of failure mechanics were found and the conditions of occurrence of each failure type are summarized in a chart. In addition, a new approach for estimating the bearing capacity of a strip footing on two-layered c-ϕ soils is proposed. A comparison with available methods in the literature has confirmed the reliability of the proposed method, showing the application limitation of the past research.