Study on the Failure Surface of Heterogeneous Soil at the Passive State

Abstract

Earth pressure problem is one of the key research subjects in soil mechanics and geotechnical engineering. Heterogeneous soil is always encountered in engineering practices. However, the classical Rankine and Coulomb’s earth pressure theories don’t take into account of the effect of heterogeneity on the failure surface and the earth pressure. In this paper, the failure surface of heterogeneous soil at the passive state is investigated using the geotechnical FEM software Plaxis. The study results indicate that the failure surface at the passive state is strongly influenced by the strengths of the foundation and the lower layer soil for the backfill consisting of two-layered soils. The failure surface of the two-layered soils approaches the one of the homogeneous soil with the strength of the foundation and lower layer soil.