贵州省德江县香树坪滑坡特征及形成机制研究

香树坪滑坡位于贵州省铜仁地区德江县大坪村齐心组,为大型古滑坡。滑坡边界及前缘坡下发育多条拉陷槽,滑动方向为310～335。基于滑坡区工程地质条件和滑坡变形破坏特征,建立了滑坡形成机制概念模型:在河谷形成及演化过程中,香树坪斜坡以滑移-弯曲演化。滑坡前缘拉槽LC6#和LC3#依次形成,其卸荷和临空效应导致上部坡体进一步变形。滑坡坡脚区因上部坡体进一步滑移变形而应力集中,坡体稳定性整体降低。当坡脚区失稳时滑坡发生。数值分析很好地再现了滑坡演化过程及机理。研究成果可对西部山区类似类滑坡发育条件及识别研究提供参考。

CHARACTERISTIC AND FORMATION MECHANISMS OF XIANGSHUPING LANDSLIDE IN DEJIANG COUNTRY IN GUIZHOU PROVINCE

Xiangshuping landslide is located at the Qixin couple of Daping county in Dejiang county, Tongren prefecture, Guizhou province. It is a large ancient landslide. There are several pull trap slots in the boundary of the landslide and the front of the lower slope. Sliding direction of the landslide is 310～335.On the basis of the Engineering geological conditions and deformation and failure characteristics of landslide area, this paper builds the conceptual model of the formation mechanism. In the valley formation and evolution, Xiangshuping landslide evolves in the forms of sliding and bending. The pull slot LC6# and pull slot LC3# in front of the slope are sequentially formed. Their unloading and overhead effects lead to further deformation in upper slope and causes stress concentration at the base of slope and drop of overall slope stability. Landslide occurs while the base of slope is unstable. Numerical analysis well reproduces the landslide evolution and mechanism. The result of the research can provide reference for analogous landslide developmental conditions and identifications of the western mountains.