大型顺层岩质滑坡的空间分布及变形破坏演化模式

Evolution model of spatial distribution and deformation failure at large bedding rock landslides

为研究大型顺层岩质滑坡的空间分布形态及变形破坏演化模式,综合采用现场调查和数值模拟研究鸡尾山滑坡软弱夹层的物理力学参数随时间和位置的变化规律,提出锁固段渐近失效模型,基于软弱夹层滑动理论编写了有限元计算模型,验证软弱夹层扩大至一定范围并达到临界破坏状态时发生破坏的现象,通过数值模拟与现场数据进行比较验证模型的有效性。结果表明,鸡尾山大型顺层岩质滑坡滑动体积大约为560×10^(4)m^(3),滑动面倾角约20°;鸡尾山滑坡属于典型的推移式岩质滑坡,滑体可分为推移段和锁固段,锁固段损伤破坏是滑坡失稳的根本原因。数值模拟得到的锁固段体积和后缘张拉裂缝的宽度结果与现场观测结果一致。

This paper is an effort to investigate the evolution model of spatial distribution and the deformation failure at large bedding rock landslide.The study involves investigating the law behind physical and mechanical parameters changing with time and position of Jiweishan landslide weak interlayer by scene investigation and numerical simulation;proposing an asymptotic failure model of the locking section;writing a finite element calculation model;verifying the failure condition caused by expending of weak interlayer to a certain range and even to the critical failure state;and verifying the effectiveness of the model by comparing numerical simulation and field data.The results show that the sliding volume of the large bedding rock landslide in Jiwei Mountain is about 560×104 m 3,and the inclination angle of the sliding surface is about 20°;Jiweishan landslide is typical push type rock landslide,which is divided into a sliding section and a locking section,and the locking section failure causes the instability of the landslide.The volume of the locking section and the width of trailing edge tension cracks obtained by numerical simulation are consistent with the results from the field observations.