Study On The Formation Mechanism Of Shizishan Lanslide And Its Anti-slide Pile Support Technology

Landslide is the most destructive global natural disaster,and is also recognized as only the second natural geological disaster after earthquake.China is one of the most serious landslide geological disasters in the world.With the rapid development of China's national economy,a variety of landslide accidents have followed due to the over-development of people,the influence of various natural environmental conditions,and the restrictions of different geological conditions.Based on the geological disaster control project of shizishan landslide in wukang street,deqing county,this paper analyzes the slope stability by using the slope stability analysis software FLAC^3Dand Rocsicence Slide,based on the limit equilibrium method and strength reduction method.The control scheme is determined and the landslide is designed according to the research results.The optimal design of pile position,pile length and pile spacing of anti-slide piles was carried out based on FLAC^3Dand Spencer method in Slide.The main research contents are as follows:?1?Through field investigation,the geological survey has learned that the internal cause of the shizishan landslide is determined by its own geological and geomorphic geographical conditions,and the main internal causes affecting the shizishan landslide include:rock and soil types,hydrogeological conditions,topographical and geomorphic conditions,etc.Gneiss type:the permeability of rock and soil between the difference is the internal conditions of forming landslide slip zone,slope table cover the quaternary system of artificial filled soil and underlying weathered tuff permeability is good,lower part of a sandwich after weathering material like clay,poor permeability,water-resisting layer,rainfall infiltration rainwater can be collected after discharge,form a larger uplift pressure,and the slope of old landslide in the form of crack,provides conditions for rain water infiltration.?2?hydrogeological conditions:the dominant role in the formation of the shizishan landslide is the activity of groundwater.According to the borehole data,the groundwater buried in the landslide is relatively shallow,the rock and soil mass is basically in the state of water saturation,the groundwater action softens the shear strength of rock and soil mass,and produces buoyancy to the permeable layer.?3?Topographical and geomorphic conditions:the slope body is steep and slow,the upper slope is about 25°?30°,the lower slope is 5°?15°,the steep and slow terrain is conducive to groundwater to the slope foot;In addition,the development of microgeomorphology on the landslide body,the bottom of the central steep ridge terrain is"concave",which is conducive to the collection and infiltration of rainwater.?2?According to the engineering geological conditions of the main landslide and based on Slide software,a two-dimensional slope model was established.Bishop method,Janbu method,Spencer method and M-P method were used to calculate the stability of the slope under natural conditions and rainstorm conditions.?3?The three-dimensional calculation model of the slope was established by using the finite element software FLAC^3D,and the stability and displacement of the slope under natural conditions and rainstorm conditions were simulated and analyzed by combining the strength reduction method.At the same time,according to the increment of the maximum shear strain,the position of the sliding surface of the slope was determined,and the stability of the slope was evaluated.?4?Of the landslide by anti-slide pile supporting,with elastic-plastic theory on the stress and strain analysis,carried out by using slope,anti-slide pile displacement simulation,optimization of the project of anti-slide pile,pile length and pile cross section design parameters,such as,give full play to support performance,determine the most reasonable and economic,security,slope anti-slide pile reinforcement scheme.