Seismic stability of anti-sliding cantilever retaining wall with EPS composite soil

Shaking table tests are conducted on the inverted T-shape cantilever retaining walls with an anti-sliding tooth to comparatively study the seismic stability characteristics using EPS composite soil and Nanjing fine sand as backfills, respectively. The seismic responses of wall-soil system and dynamic earth pressure distribution behind the wall are comparatively analyzed. The influences of displacement modes of retaining wall and the properties of backfill on dynamic earth thrust are emphasized. The experimental results indicate that when using EPS composite soil as backfill, the acceleration response on the backfill surface is relatively small. The contribution of dynamic earth thrust to the wall rotation increases with the increasing input peak excitation. The inertial interaction between wall and soil is closely related to the dynamic deformation mode of backfill. The distribution of dynamic earth thrust behind the wall when using sand as backfill is obviously different from that using EPS composite soil. The relationship between the dynamic earth thrust and the peak ground acceleration for sand-wall system is nonlinear, and the acting position of earth thrust is approximately 2/3 wall height. A linear relationship exists for EPS composite soil-wall system, and the acting position is close to 1/3 wall height. The acting position of earth thrust slightly moves down as the peak ground acceleration increases for the two test systems. Based on the comparison between test results and several classical analytic solutions, some suggestions are proposed regarding the seismic analysis of flexible retaining wall when using EPS composite soil as backfill.