Study On The Instability Mechanism And Prevention Technology Of Bedding Rock Slope In The West Mountain Of Hubei

Previous engineering practice has proved that the occurrence of severe accidents caused by bedding landside is not uncommon,which is great harmful.It comes down to two reasons: insufficient understanding of the failure mechanism of bedding landslide and lack of experience in strengthening and controlling such kind of slope.Based on one example of bedding rock slopes along the highway of Enqian and Enlai in this paper,theoretical analysis and numerical simulation are carried out to study in detail the mechanism of plane sliding failure and dual reduction factor method.Finally,discrete element program 3DEC is used to study the failure process of slope failure and the influence factor analysis of prestressed anchor cable reinforcement.The main work in this thesis is as follows:The failure modes of bedding rock slope are divided by the geometrical form of slope failure.Discrete element universal program 3DEC is used to simulate three typical plane sliding failure modes—single plane sliding failure?double plane sliding failure?wedge sliding failure.The influence degree of the slope stability is studied based on the single factor and multi-factor sensitivity analysis.The result shows that the influence degree of the slope stability is listed as follows from large to small: slope angle?slope height?dip angle of lower sliding plane?internal friction angle of rock mass?cohesion of rock mass?internal friction angle of lower sliding plane?cohesion of upper sliding plane?cohesion of lower sliding plane?dip angle of upper sliding plane?internal friction angle of upper sliding plane.Aiming at two phenomena of plane sliding failure and the double plane sliding failure,the influence on the slopes' critical damage morphology caused by reducing the shear strength parameters c and tan? in unequal proportion is studied.The results show that the critical curves of structural planes' c-tan? satisfy a linear function relationship on the situation of single plane sliding failure,the critical sliding surface is not affected by the critical state point,there is no difference between the sliding surface calculated by SRM and DRM.On the situation of double plane sliding failure,the critical curves of structural planes' c-tan? satisfy the quadratic parabolic function,different critical state points may correspond to different combinations of sliding surfaces,but the position of the main sliding surface(structural surface that intersects with free surface)is not affected.Discrete element general program 3DEC is used to simulate the collapse of the slope,and the current situation of slope under the measures of lowering slope ratio and prestressed anchor reinforcement is calculated by numerical calculation.Finally,the influence of anchor cable prestress?length of anchorage segment?row space of anchor cable?dip angle of anchor cable on the slope stability is in depth analysis.The maximum horizontal displacement and maximum vertical settlement of the slope can be reduced effectively by increasing the prestress of anchor cable in a certain range.The length of the anchorage has little effect on the maximum horizontal displacement.The increase of row space of anchor cable in a certain range will improve slope stability.In the range of 0° to 50°,with the increase of cable inclination,the safety coefficient of slope increases first and then decreases.