Analysis On Genetic Mechanism And Stability Of The Landslide In Dangxiao In Malipo County, Yunnan Province

This article selects Malipo county party school landslide as the research object. Based on collected data and field investigation, through analyzed the environmental geological conditions and characteristics of landslide. Using the water rock test and direct shear test et al, reveals the physical and mechanical properties of rock and soil mass. Based on this, advances the cause of the landslide mechanism. By FLAC numerical model is set up, analysis of the slope toe excavation stress distribution and displacement variation under different working conditions, finally using the limit equilibrium method to test stability coefficient of landslide under different conditions, On the basis of comprehensive analysis of landslide stability to forecast the development trend of the landslide, the following brief understanding and conclusion:(1)The county party committee party school belongs to the rocky landslide, landslide along the whole-strong weathering interface slip, part in the whole rock weathering layer sliding along the schistosity surface; after the slope toe excavation, landslide along the schistosity structure surface cut out. Slope sliding by topography and geomorphology, lithology, geological structure, hydrogeological conditions, internal factors such as control, rainfall and artificial cut slope is the main inducing factors of landslide.(2)By identifying the rock slices of flake, hydrophilic mineral content is high, experiment shows that piece of the physical and chemical water-rock phyllite easily under the influence of water softening and disintegration, and weathered rock mineral composition of cationic easy exhalation. Considering the physical and chemical characteristics of phyllite and landslides along the rock schistosity structure surface characteristic of the cut out. Using soil direct shear apparatus for the structure of weathered rock of suitable shear strength were determined, optimize the shear strength of weathered phyllite. Combined with the test data, experience value for the sliding zone soil c, phi values determined for inversion, provide the basis for slope stability calculation.(3)Internal factors fundamentally affect the landslide sliding.Landslide area topography steep; The overlying loose soil residual diluvial layer and weathered layer permeability is strong, medium to strong weathering bedrock phyllite layer permeability weak for relative water-resisting layer, form the unfavorable lithology combination condition; Rock structure planes and joint structure combination form adverse structural plane, and slope direction and rock schistosity plane are basically identical, is not conducive to the stability of the slope.(4)Rainfall and artificial cut slope is an important inducing factors of landslide. Heavy rain condition before excavation slope, rainwater infiltration and the overlying loose soil weathered rock due to severe increase and a decrease in mechanical properties, in full-strong weathering interface form weak layer further formation of sliding surface, front traction caused landslide trailing edge to form cracks. Excavation slope destruction of slope stress state of equilibrium, rainfall infiltration of slope degree of weight gain downward trend is obvious, slope toe shear stress increases, stress increase concentration belt extension for the sliding zone. With the increase of tensile stress, rear traction by frontal slope landslide slope continue to slide. Front sliding lead to trailing edge without sliding of rock mass deformation displacement of rock mass losing support, combined with slope direction and rock schistosity plane are basically identical, in its own gravity downhill body will face continued to slide along the schistosity structure.(5)The limit equilibrium method is adopted in the imbalance thrust method to calculate the stability coefficient of landslide under different conditions before and after the excavation; numerical simulation of landslide under different conditions before and after the excavation of slope stress distribution in the body, analysis of landslide damage and its mechanical characteristics. Two kinds of stability calculation results are basically identical, but the data smaller in the survey report in the simulation results at the same time, verify the reliability of the direct shear test results.(6)The landslide is small traction type rock landslides, slide body as a whole in heavy rain conditions will be in a state of flux, and irect threat to the safety of the construction of party school construction with has great potential safety hazard.