Rainfall infiltration is a key factor that determines the active earth pressure on an earth-retaining structure. Previous investigations on the stability of earth retaining structures were mainly conducted under the assumption that the backfills was dry, saturated, or subjected to a steady unsaturated flow, ignoring the time-varying characteristics of the rainfall infiltration process. Based on the upper bound theorem of limit analysis, this study conducted a stability analysis of a three-dimensional (3D) earth retaining structure (ERS) subjected to various rainfall infiltration patterns. An analytical model that was, capable of calculating the pore water pressure distribution due to rainfall infiltration, was employed to calculate the time-dependent pore water pressure change of unsaturated soil. A horizontal slice method was employed to take into account the change of effective unit weight of soil. Afterward, an analytical expression of the active earth pressure coefficient is derived from the energy balance equation. The effects of the 3D characteristics of ERSs and rainfall patterns on the active earth pressure coefficient and the failure pattern of ERSs were investigated. It was found that compared with plain strain conditions, the 3D characteristics of ERSs lead to a lower value for the active earth pressure and better stability. The rainfall patterns not only directly determined the stability and active earth pressure of an ERS, but also played a dominant role in critical failure pattern of the ERS.

降雨入渗是决定挡土结构主动土压力的关键因素。以往关于挡土结构稳定性的研究主要是在假设回填土是干燥的、饱和的或经受稳定的非饱和流的情况下进行的，而忽略了降雨入渗过程的时变特征。本研究基于极限分析的上限定理，对受各种降雨入渗模式影响的三维 (3D) 挡土结构 (ERS) 进行了稳定性分析。一种能够计算降雨入渗引起的孔隙水压力分布的分析模型被用来计算非饱和土的孔隙水压力随时间的变化。采用水平切片法考虑土壤有效单位重量的变化。然后，根据能量平衡方程推导出主动土压力系数的解析表达式。研究了 ERS ​​的 3D 特性和降雨模式对主动土压力系数和 ERS ​​失效模式的影响。结果表明，与普通应变条件相比，ERS 的 3D 特性导致主动土压力值较低，稳定性更好。降雨模式不仅直接决定了ERS的稳定性和主动土压力，而且在ERS的临界失效模式中起主导作用。主动土压力系数的解析表达式是从能量平衡方程导出的。研究了 ERS ​​的 3D 特性和降雨模式对主动土压力系数和 ERS ​​失效模式的影响。结果表明，与普通应变条件相比，ERS 的 3D 特性导致主动土压力值较低，稳定性更好。降雨模式不仅直接决定了ERS的稳定性和主动土压力，而且在ERS的临界失效模式中起主导作用。主动土压力系数的解析表达式是从能量平衡方程导出的。研究了 ERS ​​的 3D 特性和降雨模式对主动土压力系数和 ERS ​​失效模式的影响。结果表明，与普通应变条件相比，ERS 的 3D 特性导致主动土压力值较低，稳定性更好。降雨模式不仅直接决定了ERS的稳定性和主动土压力，而且在ERS的临界失效模式中起主导作用。结果表明，与普通应变条件相比，ERS 的 3D 特性导致主动土压力值较低，稳定性更好。降雨模式不仅直接决定了ERS的稳定性和主动土压力，而且在ERS的临界失效模式中起主导作用。结果表明，与普通应变条件相比，ERS 的 3D 特性导致主动土压力值较低，稳定性更好。降雨模式不仅直接决定了ERS的稳定性和主动土压力，而且在ERS的临界失效模式中起主导作用。