山区边坡降雨环境下的稳定性和局部风险分析

Local Hazards and Stability Analyses of High Mountain Slope Under Precipitations

为研究山区建筑高边坡受到降雨浸泡后的稳定性,以及由于排水沟因落叶堆积堵塞造成的局部积水对边坡稳定性产生的风险。基于某建筑高边坡案例,采用PHASE2有限元强度折减法,建立降雨浸泡和局部积水下的边坡分析模型,进行边坡稳定性分析。主要结论有:边坡的稳定性由红黏土与强风化层交界面控制;降雨浸泡后边坡稳定性急剧下降,且由浸泡线和上述交界面共同控制;当局部积水位置靠近上述交界面时,边坡的整体稳定性将急剧下降甚至失稳。

This paper presents a case history results of evaluating the stability of high mountain slopes after the soaking of rainfall waters,and the hazards of localized storm water accumulation induced by the blocking of drainage ditches by tree leaves on the slope stability.A case history of a building near the high mountain slope was numerically analyzed by using commercial finite element analysis software PHASE2.The numerical slope stability model of the soaked soil with rainfall accumulated at the toe of the slope was established by using the strength reduction method.The results indicate that,the controlling factor of the slope stability is governed by the properties of at the interface of the red clay and the highly weathered bedrock.Under the soaking of rainfall water,the stability of the slope reduces significantly,under this condition,the stability of the slope is controlled jointly be the soaking line and the above-mentioned interface.When the soaking line is close to the interface between the red clay and the highly weathered bedrock,the global stability of the mountainous slope reduces significantly,and even causes slope instability.