下部为基岩的浅层残积土边坡多含有地下水,通过对传统Green-Ampt入渗模型的延伸,研究含有地下水的残积土边坡强降雨入渗过程;在强降雨入渗条件下,湿润区和地下水范围内基质吸力消失,湿润峰处和基岩面处为2个潜在的危险滑动面,分别对边坡在其上稳定性进行分析,并将二者统一起来,建立考虑强降雨和初始地下水共同作用下边坡的稳定分析模型。研究结果表明:下部含有初始地下水的浅层边坡在强降雨入渗期间,由于上部土体自重的增加,边坡最危险滑裂面在湿润峰和基岩面之间可能发生转移,边坡有可能在基岩处提前于湿润峰处破坏;同时,黏聚力越小,地下水位越浅,降雨入渗期间边坡在地下水下部基岩处破坏的可能性就越大,且土体黏聚力的影响最为显著。
Most of the shallow residual soil slopes with bedrock beneath have groundwater, so the infiltration process of slope under intense rainfall was analyzed based on the extended Green-Ampt infiltration model; Because of the vanishing of matric suction in the wetting zone and the groundwater zone under intense rainfall, the slope stability analysis at the wetting front and the bedrock surface under the groundwater were studied respectively, and which were unified to establish a integrated stability analysis model during intense rainfall. The results show that the worst sliding surface probably devolves between the wetting front and the bedrock surface due to the increasing unit weight of soils during rainfall infiltration, the slope failure may occur firstly at the bedrock surface under groundwater, and not at the wetting front. Meanwhile the smaller cohesive strength and shallower groundwater table will cause more probability of slope failure at the bedrock surface under groundwater, and the influence of cohesive strength is the greatest.