Seismic response of liquefiable backfill supported by sheet-pile with different wall embedment ratios

抄録

Analysis of the seismic design of retaining structures is complex due to the intricate interplay between the response of backfill soil and supporting wall. When dealing with liquefiable soils, numerical modeling is often employed to gain insight into the mechanisms behind the resulting deformation of retaining walls during earthquakes. This paper focuses on detailed numerical modeling of two well-documented centrifuge tests of such systems from the last two rounds of LEAP, with different embedment ratios and shaking intensities, and their impacts on the system response of the sheet-pile wall supporting a liquefiable submerged deposit. First, a soil constitutive model is calibrated using data from cyclic direct simple shear tests. The two centrifuge models with different wall embedment ratios and shaking intensities are then simulated and used for validation and assessment purposes. The numerical model shows a successful performance in capturing the system response for both models. Assessing details of the stress-strain response in the numerical model reveals two dominant cyclic deformation mechanisms in the backfill soil: cyclic mobility and the accumulation of residual deformation. The success of the adopted numerical approach in capturing the experimental results is attributed to the constitutive model's ability to simulate both of these cyclic deformation mechanisms.