Focusing on a T-shape cantilever retaining wall in a liquefiable site, a series of shaking table model tests were conducted to investigate the seismic stability characteristics of the wall when using EPS composite soil isolation piles (WEP), EPS composite soil isolation walls (WEW), and backfilled natural fine sand from Nanjing (WSS). The seismic response characteristics of the model ground soil and the retaining wall for the three models were comparatively analyzed regarding the acceleration, displacement, dynamic earth pressure and excess pore water pressure ratio. Moreover, the seismic performance of anti-liquefaction measures in the liquefiable ground with EPS composite isolation structures were discussed from the view of the phase characteristics and energy consumption. The results indicate that under the same peak ground acceleration, the excess pore water pressure in the WEP and WEW models is significantly lower than that in the WSS model. Different from WSS, WEP and WEW exhibit a segmented distribution with the buried depth in acceleration amplification factors. The embedding of isolation structures in liquefiable sites can reduce the wall sliding and rotational displacements by approximately 25%–50%. In addition, the out-of-phase characteristics of dynamic earth pressure increment are evidently different among WEP, WEW and WSS. There is an approximate 180° phase difference between the dynamic earth pressure behind the wall and the inertial force in the WEP and WEW models. EPS composite soil isolation structures show good energy dissipation characteristics, and especially the isolation wall is better than isolation pile. The displacement index of WSS retaining wall is significantly larger than that of WEW and WEP, indicating that EPS composite isolation piles and wall play an important role in the mitigating damage to the retaining wall. This study can provide references for the application of isolation structures in the liquefiable ground soil regarding the seismic stability.

中文翻译：

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可液化场地 T 形挡土墙的地震响应和减灾措施


以液化场地的 T 形悬臂挡土墙为研究对象，开展了一系列振动台模型试验，研究了使用 EPS 复合隔土桩 （WEP）、EPS 复合隔土墙 （WEW） 和南京回填天然细砂 （WSS） 时墙体的抗震稳定性特性。比较分析了3种模型地基土和挡土墙的加速度、位移、动土压力和超孔隙水压力比的地震响应特性。此外，从相特性和能耗的角度讨论了 EPS 复合隔振结构液化地基中抗液化措施的抗震性能。结果表明，在相同的地面峰值加速度下，WEP和WEW模型中的超额孔隙水压力显著低于WSS模型。与 WSS 不同，WEP 和 WEW 在加速度放大因子中表现出与埋深的分段分布。在可液化场地嵌入隔离结构可以减少约 25%–50% 的墙壁滑动和旋转位移。此外，动土压力增量的异相特性在 WEP、WEW 和 WSS 之间存在明显差异。墙后的动态土压力与 WEP 和 WEW 模型中的惯性力之间存在大约 180° 的相位差。EPS复合土隔震结构表现出良好的耗能特性，特别是隔震墙优于隔离桩。 WSS 挡土墙的位移指数显著大于 WEW 和 WEP，表明 EPS 复合隔墙桩和墙体在减轻挡土墙损伤方面发挥着重要作用。本研究可为隔振结构在液化地基土中地震稳定性的应用提供参考。