大光包滑坡不连续地质特征及其工程地质意义

大光包滑坡是2008年汶川地震触发的最大规模滑坡，也是世界上百年罕见的大型滑坡，引起国内外学者持续争论和广泛研究. 本文为研究地质构造对大光包滑坡影响，基于现场照片、遥感图及岩体结构面产状数据，首先开展大光包滑坡断壁、滑带及滑坡堆积体不连续地质特征调查，进而分析该不连续地质特征成因，进一步讨论强地震动、不连续地质界面组合及地下水对大光包滑坡启动影响. 研究结果表明:震前随大水闸背斜构造演化发育的断层、层间错动带及优势岩体结构面等不连续地质结构控制了大光包滑坡边界的形成和滑体堆积过程；汶川强震为这些不连续地质结构破坏提供了动力条件；地下水伴随着强震过程不连续地质界面贯通促使了大光包滑坡快速启动. 

Discontinuities and Engineering Geological Significances of Strong Earthquake-Induced Daguangbao Landslide

The Daguangbao （DGB） landslide is the largest landslide triggered by the 2008 Wenchuan earthquake and considered as one of the largest of these events in the world. In this paper, the geological cause of the DGB landslide was analysed on the basis of rich photographs, remote sensing images, and orientation data. The discontinuity features of the landslide scarp, slip zone, and deposition were investigated firstly, and then the formations of these discontinuities were studied. The effects of strong seismic shaking, geological discontinuities, and ground water on the DGB landslide were discussed. The results showed that the initiation and deposition of the DGB landslide were dominated by geological discontinuities such as local faults, bedding faults, and joint sets, which were developed during the formation of an anticline. Strong ground shaking of the Wenchuan earthquake induced the failure of these geological discontinuities, and ground water might have finally initiated the DGB landslide during the earthquake-induced discontinuity connectivity.