A high-position destructive rockfall, significantly influenced by post-seismic effect of Wenchuan earthquake in 2008 and associated aftershocks, was reported in Miansi Town of Wenchuan County, Sichuan Province, China. About 3,000 m 3 of rock at high position detached from a dipping rocky slope, which manifested as a translational motion. Detailed field investigation, geological mapping, kinematic analysis, and numerical modelling are presented to comprehensively analyze the complex failure mode of the post-seismic rockfall. The results demonstrated that the sliding surfaces are mainly controlled by the internal shear discontinuity sets. The backscarps are progressively evolved from the tensile cracks at rear slopes caused by the Wenchuan earthquake. Because of the combination effect of heavily shocks of previous earthquake and local geomorphology of the rockfall with beneficial for facilitating the magnification effect on peak ground acceleration (PGA), the rock mass of slopes is dramatically damaged and fractured. The original intact slopes finally developed to the shattered slopes as an optimum birthplace for the post-seismic rockfalls. It should be noticed that intensive precipitation plays a triggering factor that generates the hydrostatic water pressure in the rear cracks and the uplift pressure at the bottom sliding surface within a short time. The evolution processes are divided into three stages: slope relaxation stage, rock shattering and disaggregation stage, and high-speed falling stage. Velocities, energy, and bounce heights of falling rock blocks are computed by the RocPro3D software for understanding the corresponding kinematics. The paper can provide an insight into post-seismic rockfalls in the tectonic areas associated with the combination of seismic activities and intense rainfall.

中文翻译：

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以详细调查和数值模拟为例的破碎山脉震后落石破坏模式分析

四川省汶川县绵寺镇发生高位破坏性落石，受2008年汶川地震震后效应及相关余震影响较大。大约 3,000 m 3 的高位岩石从倾斜的岩石斜坡上脱离，表现为平移运动。详细的现场调查、地质填图、运动学分析和数值模拟，以综合分析地震后落石的复杂破坏模式。结果表明滑动面主要受内部剪切不连续集控制。后缘由汶川地震后坡的张拉裂缝逐渐演化而来。由于前次地震的强烈冲击和落石局部地貌的共同作用，有利于促进峰值地面加速度（PGA）的放大效应，边坡岩体受到剧烈破坏和破碎。原始完整的斜坡最终发展为破碎的斜坡，成为震后落石的最佳发源地。需要注意的是，强烈的降水是在短时间内产生裂缝后部静水压力和底部滑动面隆起压力的触发因素。演化过程分为三个阶段：斜坡松弛阶段、岩石破碎解聚阶段和高速下落阶段。速度、能量、RocPro3D 软件计算落石块的弹跳高度，以了解相应的运动学。该论文可以深入了解与地震活动和强降雨相结合的构造区域的震后落石现象。