Estimation of Lateral Earth Pressure On Retaining Wall Upon Unsaturated Soil: A Numerical Study

Abstract

The evaluation of lateral earth pressure of soil mass on geotechnical structures like retaining walls, bridge abutments, excavations has gained tremendous importance from stability assessment point of view, over the past few decades. Understanding the magnitude and distribution of lateral earth pressures allows geotechnical engineers to design structures that can withstand the loads imposed by surrounding soil to greater extent. Accurate assessment of lateral earth pressure helps to prevent structural failures such as tilting, sliding, or overturning. Although most of the researches have been done to determine the lateral earth pressure of structures, generally, resting upon saturated soil, but the presence of negative pore water pressure in case of unsaturated soils can result in much variation in the results. By accounting for the matric suction in unsaturated soils, engineers can predict the overall stability of a structure with much accuracy. This paper aims to determine the lateral earth pressure of a retaining structure, supported on unsaturated soil using lower bound limit analysis coupled with second order conic programming for optimization. Employing a parametric analysis, the effects of numerous parameters, such as height of the wall, unit weight, backfill surface and wall back face inclination, water table location, and soil–wall interface friction, have been noted.