崇州万家中学后山滑坡成因机制与稳定性分析

Study on Formation Mechanism and Stability of Houshan Landslide Behind Wanjia Middle School in Chongzhou

为了对万家中学后山滑坡进行成因机制探讨与稳定性评价,现对其区域地质特征作详细勘查。结果表明:勘查区地层地貌特征明显,地层软硬相间,滑坡体主要为块碎石土,且分布广泛。该滑坡可能沿堆积体与基岩之间软弱结构面滑动,且其中部存在临空面,为其剪出提供了很好的条件,而降雨及地表水的渗入是坡体拉裂及变形的主要诱发因素。采用传递系数法计算该滑坡全坡段在自重、自重+暴雨、自重+地震等3种工况下的稳定系数。综合可知该滑坡处于基本稳定状态,但在暴雨状态下有加剧失稳的可能。

To investigate formation mechanism and stability of Houshan landslide ,its detailed areal geology characteris-tics was surveyed .The results indicate that the characteristics of landform in exploration area are obvious ,and the hard layer alternates with the soft layer ;the main landslide body is composed of massive gravel soil and might slide on the weak structural surface between the accumulation layers and bed rocks ;in the middle of the landslide ,there is a free face ,which provids favorable conditions for the shear failure ;the penetration of rainfalls and surface water are the main inducing factors for the landslide .Here ,the whole slope stability coefficient under dead load ,dead load ＋ rainstorm , dead load ＋ earthquake were analyzed by using transfer coefficient method .The analysis indicate that the landslide is basically stable ,but may lose its stability under rainstrorm condition .