唐家山滑坡成因机制与堰塞坝整体稳定性研究

 根据唐家山滑坡的地质背景，研究滑坡及堰塞体工程地质特征，分析唐家山滑坡类型及发生的地质成因机制；基于唐家山堰塞体的岩体结构稳定性分析、宏观现象监控与地表位移监测，研究堰塞体的整体稳定性。研究得出如下结论与启示：(1) 唐家山滑坡属于基岩顺层滑坡，是典型的地震诱发高速滑坡，滑坡滑动带可能发育在层间剪切带，滑坡区发育的构造背景为复式倒转背斜的一翼。(2) 唐家山堰塞体整体结构以块状岩体为主，上覆风化松散堆积物，整体地质稳定性较好；堰塞体地表位移监测显示，泄洪对地表位移有影响，最大位移约140 mm，随后位移增量较小，目前处于稳定状态。(3) 应注重地震诱发滑坡→堰塞湖→溃决→洪水的“多米诺”链式灾变研究；应注重含层间剪切带斜坡的工程地质调查分析和地震滑坡危险性研究。

STUDY OF GEOLOGICAL ORIGIN MECHANISM OF TANGJIASHAN LANDSLIDE AND ENTIRE STABILITY OF LANDSLIDE DAM

By geological survey and engineering geological characters analysis of Tangjiashan landslide，the landslide types and geological origin mechanism are studied. On the base of the rock mass structure analysis and surface displacement monitoring，the entire stability of landslide dam is studied. The conclusions are achieved：(1) Tangjiashan landslide is of high speed rock slide triggered by earthquake，and is located in a consequent slope of complex overturned fold. Landslide sliding zone is possibly situated in interbedded shear zone. (2) Landslide dam material is mainly block rock mass overlying with weathered incompact accumulation，and entire stability is good. Flood affected the surface displacement of landslide dam with the maximum displacement of 140 mm. Increment of surface displacement is down after flood，and landslide dam is stable now. (3) The chained hazard study of earthquake landslide→dammed lake→breach→flood with domino effect should be emphasized. Engineering geological survey and seismic risk study of slope are included interbedded shear zone.