The Study On Deformation Mechanism And Stability Of Ⅰ Landslide For Diao-zhong-dam In The Zhongxian County, Chongqing City

Ilandslide of diao-zhong dam is located in Zhongxian Country, Chongqing Cityabout18km southwest of the Xinsheng Town of diao-zhong dam on the left bank, thefactors which influence the stability of landslide, water is the main external causeinducing the landslide instability. Rainfall changes a landslide in unsaturated soilwater content, pore water pressure changes in the body, leading to the sliding bodyand sliding zone soil shear strength change, thus affecting the stability of the landslide.In this paper, using the basic theory and the theory of rainfall infiltration, unsaturatedseepage software SEEP/W is used to examine the different groundwater level, rainfallintensity, under the condition of the seepage situation of landslide body, thus obtainedthe distribution of pore water pressure and volumetric water content in the body. Onthis basis, using FLAC3D to simulate the stress and deformation of the slope bodywith the change of rainfall intensity, the landslide is analyzed in the natural state andthe stability of the rainfall condition. Get the following:1) Ilandslide of diao-zhong dam leading edge has three secondary landslidedeformation is obvious, then edge round-backed armchair shaped form, theplane is a ribbon, lateral boundary on the landscape of0.5~1.0m small scarpand tensile fracture of0.1~0.5m wide.2) through the analysis of landslide deformation monitoring data, thinking aboutIlandslide of diao-zhong dam overall in the stable state, the overall instabilityis unlikely, but front, obvious secondary landslide deformation is in unstablestate, in the presence of instability of the rain.3) studies have shown that the formation and evolution of the landslide isdivided into the following phases: deep valley, bank slope weathering erosionstage, the riverbed grooves, bank slope rock cavity forming, rock collapse,bank slope erosion slow, steep shore back stage, colluvial deposit formation,steep cliffs, continue to back stage, stage of formation of landslide.4) Accumulated in the process of rainfall infiltration, rainfall in the upper stoneslow fast and lower silty clay soil infiltration infiltration, the upper slopesdownward infiltration from transient saturated zone, formed from top to toepenetration of dynamic water pressure. As the rain continued, slippery body basic is in a state full of water. Deposit in the rain under the action of load, theintensity of softening and hydraulic, the leading edge and trailing edge ofmainly tensile deformation; Central is a compression compressiondeformation or smoke long wave deformation, such as5,6pile; This rule isalso proved that the deformation mechanism of landslide area for tractionsliding deformation.5) Through stability calculation results show that the landslide stabilitycoefficient is greater than1.15under natural conditions, relatively stable; Inthe overall stability in the cases of heavy rain is between1.053~1.078,shows that the landslide was basically stable state, but its slippery body hasthe possibility of instability, so need to prepare the corresponding protectivemeasures.