The Failure And Formation Of The Jingquan Landslide Of Three Gorges Reservoir

Landside is one of the main geological disaster, and in the west of China’smountainous region is also frequently occur, especially in the three gorges reservoirarea from building to test water to the formal completion of water storage, in theperiodic water every year (October to early April the following year) and return (themiddle of June each year to the end of September), the reservoir bank slope ofreengineering has very strong induced, reservoir area has more than a year, a lot ofloose body slide, cause back a lot of bank slope, the sediment concentration in thereservoir area increases, the database is threatened by a large, seriously affects thenormal operation of the three gorges reservoir area.In this paper, according to the Jingquan landslide, located in left bank of the Pengriver, belongs to the tributary of the Yangtze river level I tributaries. The landslidefront elevation is165m or so, the three gorges reservoir area175m will lead to floodthe edge of landslide10m height space, combined with reservoir water cyclicalchange on preceding strong erosion, soil degradation, inducing the possibility ofpotential sliding. This paper is according to related survey data in the borehole data,using the knowledge of the geology and geomorphology, have a deeper understandingto the Jingquan landslide landform, stratum lithology, hydrology geology, materialcomposition and spatial configuration, and the main research results are as follows:(1) According to the relevant data of the landslide, and found that the severe (γ),precipitation (q), material separation type deposit, valleys, rocks of content in formand substance of all are consistent with the characteristics of viscous debris flowdeposit, and comprehensive geological landform condition of the region, determine itspredecessor may be debris flow deposit.(2) On the basis of debris flow deposit, according to the failure pattern anddeformation characteristics of the landslide, the Jingquan spring of landslideformation are divided into five stages:1) erosion terrace and the formation of thesteep cliff;2) loose collapse colluvial objects forming stage;3) slope debris flowdevelopment phase formation;4) the old landslide formation;5) the old landslideresurrection of local phase, and the mechanism for each stage was studied.(3)Combine the landslide slip surface line form, by using the transfer coefficientmethod, calculate the selection of different regions of the I-I ’, II-II’ and V-V ’on thestability and study its stability and inducing factors, and analysis the main factors toprovides the certain reference value for landslide governance.(4)Using the fixed c or φ, another is variable, in step2kPa,1°, respectively, andsensitivity analysis each area, obtained the φ values change influence on the stabilityof the landslide is more.(5) According to the position of landslide shape and the possibility of sliding, thesuggestions of landslide treatment measures are put forward.