DEFORMATION MECHANISM OF BAOZHA LANDSLIDE WITH PARAMETRIC BACK ANALYSIS

The reactive mechanism of large landslide is complicated and is a key point of landslide research.The Baozha landslide is a typical large landslide in Enshi.Its stability is urgent to be evaluated in order to keep safety for people.Thid paper is based on the engineering geological condition investigation and analyses the formation mechanism.A 2D model is developed.With the FLAC software and based on the borehole displacement data,this paper inverses the rational calculation parameter of the soils and rocks forming the landslide.Considering landslide natural state and river trenching,three-simulations are done.The results show the following three points:(1)Baozha landslide is a pulling landslide.It is developed in easy-sliding strata-sandstone and muddy stone of Silurian System.Laogou river erosion and rainfall are the main induction factor.The slope front edge failed at the beginning.Then the deformation developed to middle and back of the slope.At last,the landslide happened.(2) at present,the main factors that influence the deformation and stability of the landslide are the Laogouhe river cutting and rainfall.(3)the Baozha landslide is stable now.With the river cutting deeper,this landslide is possible to have a progressive failure.The suggestion is that the front toe of the landslide should be improved as soon as possible.