Numerical Simulation Analysis And Protection Design For High Slope Stability Of Weathered Shale In Expressway

China is the largest developing country in the world.It is also the largest country in the world that has the largest scale of traffic and civil works.Along with China’s economic development and urban construction,the construction and construction of highways,railway networks,buildings,factories and water conservancy facilities also increase.In recent years,the continuous expansion of cities has made the use of land resources strained.Many projects have to choose mountain areas and terrain with large and undulating hilly areas for construction and development.There are a large number of slope problems in mountainous and hilly areas,which have more and more influence on construction and people’s life,and a series of instability problems appear more frequently.The effects and hazards of landslide,landslide and debris flow caused by the slope instability are becoming more and more serious.Slope stability has always been a typical problem in geotechnical engineering.Because of its characteristics of multiple,destructive and uncertainty of soil parameters,the slope is widely concerned by engineers.The stability of the cutting slope is related to the smooth progress of the high road construction in the mountain area.According to the actual problems in the construction project of Zhangjiajie-Sangzhi expressway,this paper expounds the principle of FLAC3D numerical analysis,analyzes the strata lithology,geological structure,topography and hydrogeology and other conditions of the landslide area,and discusses the mechanism of the landslide deformation and destruction,and applies the finite difference of Flac3D to the nature.The slope and the stability of the slope after the stage excavation are simulated,and the distribution of the displacement field,stress field and plastic zone of the complex three-dimensional landslides are analyzed,and the stability of the landslide is evaluated according to the stress and strain of the typical landslide section.In order to guide practice,the method of combining excavation unloading and support means is put forward to control the slope,and the suitable protection scheme is selected through the simulation of various supporting methods.Based on the field investigation of Zhangjiajie-Sangzhi expressway LK6+550~LK7+220 sections,I selected LK6+850 slope as the research object of this paper numerical simulation analysis,identified six different slope supporting plan.By LK6+850 slope in the Flac3D numerical simulation after six support scheme,key research of slope stability,the displacement and the stress variation and distribution,the results show that the maximal safety coefficient was 1.45 for the plan five;The maximum displacement of the X direction of plan two slope is the minimum in all the plan;And the stress value of the X direction of plan five slope is the minimum;The maximum unbalanced force in the process of excavation and the cost of the plan five slope is minimum.Comprehensive the above rule can be concluded that the five best protection scheme,and the most economical,is LK6+550～LK7+220 section of optimal supporting scheme.And the research idea of this paper can provide reference for the similar research.