汶川地震触发平溪村滑坡特征及成因分析

Characteristics and cause analysis of the Pingxi landslide triggered by the Wenchuan earthquake

摘要: 平溪村滑坡是汶川地震触发的高速岩质滑坡,面积为3.7×104m2,体积约65×104m3。滑坡距离映秀—北川发震断裂带中的石坎断层不足500m,在强大地震力作用下,滑坡滑动面陡峭、粗糙,与重力作用下呈圆弧、平滑的滑面迥异。地震触发的滑坡可分为三个阶段:①震动拉裂阶段;②摩擦阻力降低、"锁固段"剪断阶段;③滑体溃滑,高速流动堆积阶段。然后结合结构面的力学分析,通过数值模拟对地震作用下的应力变化和震裂机制进行了初步分析。

Abstract: The Pingxi landslide is a highspeed rock landslide located in Pingwu County of Mianyang City.It was triggered by the Wenchuan earthquake.It covers an area of 3.7×104 m2 and its volume is 65×104 m3,the sliding direction is about 340°.This landslide is mainly composed of Cambrian crystalline limestone,with the development of the following two control structural plane: ① N55°-65°W /NE and ② N75°-85°E /SE.The distance between the landslide and the Shikan fault in Yingxiu-Beichuan seismogenic fault i...