中文摘要：

针对澜沧江古水水电站争岗滑坡堆积体工程地质条件,在室内剪切试验、工程类比、参数反演基础上综合确定了岩土体力学参数及其统计分布规律.采用基于黏聚力c与内摩擦角φ相关抽样下的蒙特卡罗法对堆积体典型剖面进行了多种工况下的可靠性分析,预测了其未来的变形失稳特征.研究结果表明：当前堆积体B—B′剖面在正常运行工况下的破坏概率为23.4%,暴雨工况下为55.2%,若不加治理堆积体极有可能产生失稳,这与现场勘探成果表明的堆积体在正常运行工况下稳定、暴雨工况下处于蠕滑变形状态相吻合.在此基础上根据工程稳定性要求,提出了相应的防护、加固措施,使堆积体支护后在暴雨工况下的破坏概率降低至6.2%.

英文摘要：

According to the special engineering geological conditions of Zhenggang landslide deposit in Gushui Hydropower Station on Lancang River,the mechanical parameters and their statistical distribution were determined based on the laboratory direct shear tests,engineering analogy and back analysis of parameters.The reliability analysis of typical sections of the landslide deposit under various working conditions were performed by means of the Monte-Carlo method combined with the relevant parameters of cohesion c and internal friction angle φ.The potential instability modes and deformation characteristics were predicated.The results indicate that the failure probability of the B-B section is 23.4% under the normal operating conditions,and it is 55.2% under the rainstorm conditions.If the landslide deposit is not treated,it may be unstable.It is consistent with the field investigations under the above two conditions,that is,slow sliding deformation.On such a basis,the corresponding protection and reinforcement measures are proposed according to the engineering stability requirements.The failure probability of the landslide deposit is reduced to be 6.2% under the rainstorm condition.