“8·12”山阳滑坡视向滑动特征与运动过程

Characteristics of Apparent Dip Slide and Movement Process of the 8.12 Shanyang Rockslide

2015年8月12日00:30,陕西省山阳县中村镇发生山体滑坡灾害,体积约168万m3,造成8人死亡,57人失踪的重大灾难性滑坡灾害,直接经济损失约5亿元。在对滑坡几何尺寸、滑坡结构以及剪出口等实地调查的基础上,从层状块裂结构、山体倾向阻挡、临空视向剪出、驱动块体下滑以及块体阻滑等五方面分析了山阳滑坡产生视向滑动的地质条件,并分析认为山阳滑坡具有典型的视向滑动特征,山阳滑坡沿真倾角方向经历了长期的蠕动滑移变形过程与滑床层内强烈的层间错动,同时,滑坡最终沿视倾角方向形成整体高位滑动剪出;通过分析山阳滑坡的运动过程,结合其滑坡堆积体的分布结构特征,滑坡的整个运动过程划分为视向剪切滑动区、整体滑动堆积区、碰撞折返堆积区以及前部碎屑抛洒区。

At 00： 30 a. m. August 12 th 2015,a rockslide with the volume of 1. 68 million cubic meters occurred in Zhongcun town,Shanyang in Shaanxi province,which resulted in a catastrophic rockslide with 8 death,57 persons missing and nearly 0. 5 billion RMB direct economic loss. Based on the investigation of geometric dimension,structure of sliding rockmass and the shear outlet,the geological conditions of apparent dip slide of the rockslide were analyzed according to the following factors including Bedding block-broken body,Inclined rockmass barrier,Apparent dip exiting,driving-rock mass sliding and the slide resisting block; and it was considered that the Shanyang rockslide took on typical characteristics of apparent dip slide which included long-term creeping along the dip angle and intercalated sliding in the slide bed,and overall slide with high-locality along the apparent dip angle.By the means of analyzing the movement process and the structure distribution of the sliding mass,the movement process of the rockslide can be divided into apparent dip shear slide zone,main slide accumulation zone,collision and retracing accumulation zone,fragment scattering zone.