Active Earth Pressure Distribution inside Narrow Backfill Considering Soil-Arching Effect

Abstract

A narrow backfill refers to the limited space behind a retaining wall, constructed in front of an existing structure or rock face. It is known that the use of the classical analytical methods, developed for infinite half-spaces, is not appropriate for narrow backfills. In this study, the limit-equilibrium analysis with bilinear planar slip surfaces is employed and a theoretical methodology is proposed for the estimation of the active earth pressure inside a narrow backfill, considering the soil arching effect. The suggested approach can estimate the distribution of vertical, horizontal, and shear stresses everywhere inside the narrow backfill. It is observed that, as expected, the distribution of earth pressure against the retaining wall is curvilinear due to the arching effect. The influence of the backfill width, surcharge pressure, backfill internal friction, wall–soil interface friction, and rock face–soil interface friction on the earth pressure distribution is studied. The proposed methodology provides acceptable results when compared with pre-existing analytical and numerical studies. Therefore, the suggested approach can be used for the analysis of narrow backfill retaining walls.