Soil and structure inertia factors for seismic bearing capacity of strip footing embedded in soil slope

Abstract

In this paper, the seismic bearing capacity factors for a strip footing embedded in the face of a soil slope are evaluated using the lower-bound, upper-bound, and 15-Node Gauss element formulations within the framework of Finite Element Limit Analysis (FELA). Historically, most studies have either neglected the effect of soil inertia or assumed identical inertia effects for both the soil and the structure. In this study, a pseudo-static approach is employed to separately evaluate the effect of soil and structure inertia, enabling the estimation of their respective inertia factors. The results are illustrated using the design charts developed for bearing capacity, ground inclination, depth, soil inertia, and structure inertia factors. It is observed that soil and structure inertia factors decrease with increased respective seismic coefficients. The effect of slope inclination on structure inertia factors and the effect of footing embedment depth on soil inertia factors are insignificant. Employing the Multivariate Adaptive Regression Splines (MARS) technique, semi-empirical equations have been derived for all the factors. For the convenience of researchers and practitioners, a graphical user interface (GUI) software has also been developed using MATLAB to implement the semi-empirical equations and compare the results with current worldwide standards.