Research On Failure Mechanism And Stability Analysis Of Dump Slope With Weak Layer Foundation

With the continuous development of the economy,as an important basis for energy and industrial raw materials,coal demand in developing countries is growing,development and construction of open pit coal mine for the development of the national economy plays an important role,but it also brings a series of problems of engineering dump landslide is the most common disasters.Dump slope stability is an important factor affecting and geotechnical engineering control of open-pit mine production cost,research results for similar soil engineering,such as dump,and to provide reference for water conservancy dam,highway and railway subgrade,which has important theoretical significance and engineering application value.The failure problem of systematic research on the dumping Indonesia a mine slope,according to the geological condition of the study area,starting from the slope of rock and soil deformation characteristics,structure characteristics and the drainage boundary conditions,combined with numerical simulation software process mechanism analysis method,theoretical calculation and Geostudio,finite element program General,FLAC 3D in the study area,dump slope failure mechanism and stability study has made the following main results and understanding:(1)Through field investigation and engineering geological exploration,drilling,using the standard penetration test,heavy dynamic penetration means with the stratification of the soil,the development and distribution characteristics of soft soil layer and identify the slope geological structure and drainage boundary conditions are found out,and the forming mechanism of the model to determine the deformation and failure of slope dumping on the sidelines;(2)The physical and mechanical parameters of rock and soil in the slope of dumping site are studied by field test,laboratory test,engineering analogy method and parameter inversion.(3)Using SIGMA/W software on the lower part of the soft clay layer(weak layer)effectively in different loading conditions of stress calculation,different loading conditions,the lower part of the soft clay layer(soft layer)distribution and variation trend of effective stress.(4)By using the strength reduction finite element method based on the effective stress calculated on the lower part of the soft clay layer(soft layer)of different loading conditions of undrained strength ratio with the slope deformation and failure phenomenon of inverse analysis.(5)According to the results of slope stability back analysis and numerical simulation,the stability coefficient of slope is lower than 1 when the whole slope is destroyed,and the main reason may be:(1)The loading effect caused by the soft clay layer(lower layer weak)effective stress changes,so that the lower soft clay layer(soft layer)plastic deformation,strength decreased from peak strength to residual shear strength,anti sliding force decreases sharply,resulting in brittle failure;(2)According to the SPT test,and the effective stress value of the lower soft clay(weak layer)can discriminate liquefaction,results show that the lower soft clay layer(weak layer)liquefaction may occur,so that the anti slide force decreases sharply.(6)According to the deformation characteristics and numerical simulation results of the slope of the dumping site,the failure mode of the dumping site is a plastic flow and fracturing.