Study On The Stability Of Stratified Rock Slope By Simulation Experiment And Numerical Verification

Slope instability is one of the most common geological disaster in human engineering construction. The result of slope instability, induced both by human activities and natural factor, is sometimes severe and badly restricts the promotion of national economy and sustainable development of human society. Layered rock slope refers to a slope with preponderant layer-cracked stratify structures or protogenetic stratify structure within the rock mass, which is widely distributed and often leads to unstable failure. Due to the complex construction of rock mass, it is not easy to get understand the failure mechanism of bedded rock instability. In this paper, a equal thickness stratified rock is taken as prototype, laboratory tests and numerical modeling analysis are both carried out. The main work are as follows:1. Based on the similarity theory and at the requirement of physical modeling experiment,an indoor rotating slope model is designed. The model includes model stand, rotating platform,lifting system and measuring system. The rotating platform can be lifted by a movable support plate with lateral restraint function, which can simulate both 2-d and 3-d physical conditions.The platform, with a maximum rotation angle of 45°, can carry out model tests of soil or rock mass in different construction conditions.2.Four groups of modeling tests were carried out. The tests mainly investigated the following contents: the size of strata inclination, the density of rock joints, the angle of slope,the trend of joint crack, the influence of friction angle of rock mass on slope stability, and the deformation law of slope failure.3.A numerical simulation on several conditions of slope model is carried out by DDA method and DDA software. The law of failure strain of stratified rock slope and the influence on the slope stability due to the degree of joint internal friction angle are both analyzed by this study.According to the analysis, the closer to verticality the angle between joint crack trend and the rock inclination is, the less stable the slope will be; the smaller the density of joint crack is,the more stable the slope will be; the better the connectivity of joint crack is, the more likely that the slope damage will occur. The main way of bedding rock slope deformation is slide deformation along with toppling deformation and the failure mode is slipping-tension. Whenslope failure occurs, the sliding process is steped. The slope close to the surface will take the first step to slide; the deformation speed of the blocks at the top of slope is greater than the lower. The results of numerical simulation and physics modeling experiment show good agreement, and to some extent, confirm the objectivity of the conclusions obtained by the physical model tests.