Seismic Rotation Stability of Retaining Wall with Cohesive-frictional Backfill Considering Embedment Depth

Most researchs on the seismic stability of retaining walls are based on the assumption of no embedment depth, often neglecting the effect of backfill soil in front of the wall. This paper is based on the theory of upper bound limit analysis and investigates the impact of embedment depth on the seismic stability of cohesive backfill retaining walls. In this paper, the slice method is used for dividing the backfill in front of the wall and the backfill behind the wall into numerous rigid soil strips parallel to the slip surface. A wall-soil system in which the retaining wall rotates around the toe of the wall, the soil wedges in front of the wall and behind the wall slide in blocks is established. According the energy balance equation, an expression for the seismic acceleration coefficient of the retaining wall is derived in this study. The influence of factors such as the height of the backfill, internal friction angle, and cohesion of the backfill on the seismic rotational stability of the retaining wall under earthquake loading is discussed. The results indicate that when the ratio of the height of the backfill soil in front of the wall to the height of the backfill soil behind the wall (H2/H1) exceeds 0.15, the seismic yield acceleration coefficient kcr increases significantly. Neglecting the effect of the backfill soil in front of the wall in such cases would underestimate the seismic stability of the retaining wall. Verification of this method is conducted by comparing the limitequilibrium theory.