平推式滑坡多级拉陷槽形成过程及成因机理分析

FORMATION AND MECHANISM ANALYSIS OF MULTI-LEVEL RIFT TROUGH IN TRANSLATIONAL SLIDING LANDSLIDE

通过对中江县冯店垮梁子滑坡的现场调查和室内物理模拟试验研究,发现滑坡滑动过程中存在诱发次级拉裂缝产生甚至贯通的现象,结合滑坡的变形历史迹象,进行受力分析,论证拉裂缝产生形成过程及位于拉裂缝间滑带局部贯通现象,提出U形槽模式多级平推式滑动理论;对比宣汉天台乡滑坡已有对多级平推式滑坡研究,针对多级平推式滑坡后缘多级拉陷槽的形成过程和成因机理进行分析,提出多级平推式滑坡存在牵引后退式和推动前进式两种不同启动和运动模式,就两种模式各自岩性组成、构造裂隙发育情况、启动水头、启动速度、及多级滑动启动水头变化对比分析,建立地质力学机制模型。

This paper is based on the field survey and laboratory physical simulation in Kualiangzi landslide in Fengdian in Zhongjiang County.It finds that the slipping of the landslide can induce secondary tensile cracks or even through breakthrough.It combines the history of the landslide deformation with the force analysis.It demonstrates the generating process of tensile cracks and the breakthrough in sliding zone between tensile cracks,and puts forward the theory of multistage horizontal sliding in U-shaped slot model.It compares the study of multistage horizontally pushing landslide in Xuanhan county.It analyzes the formation mechanism and cause of multistage rift trough on rear edge.It compares the two different existing models of activating and motion styles,i.e.,pull-back style and push-forward style.It then establishes the geological mechanism models based on analysis of lithology,structural fissure development,inducing sliding water head height,velocity and water head height changes.