Risk Analysis Of Slope Stability In The Right Abutment Of Qianping Reservoir

When the reservoir is stored or running,the mechanical and geometric properties of the rock mass of slope will also produce corresponding changes,which will be likely to lead to the occurrence of the reservoir bank collapse or landslide.Slope instability threatens the safety of people's lives and property,affects the construction of major projects,and damages the ecological environment.The slope is a complex uncertain system.The physical and mechanical properties of the slope rock mass are random,fuzzy,and uncertain.During the construction and operation of the engineering slope,there is a certain risk of deformation,failure and instability.Therefore,it is of great theoretical and practical significance to carry out slope excavation risk analysis.This paper aims at the excavation and construction of the right abutment slope of Qianping Reservoir,and relies on the National Natural Science Foundation of China key project?U1704243?“Evolution mechanism of the landslide with the potential locked section and its dynamic-tracking early warning method in the western Henan province”.The physical and mechanical parameters are gained through geological engineering survey and laboratory test.The distribution state of slope discontinuities is achieved by 3D laser scanning.The Morgenstern-Price method and FLAC³DD three-dimensional numerical analysis software are used to consider different working conditions such as weight,normal water storage level,earthquake,sudden drop in reservoir water level,and their combinations.The slope stability,stress field and displacement field are studied systematically.Risk analysis of slope is carried out based on catastrophe theory.The mainly research results are as follows.?1?Through qualitative analysis of geological engineering,the slope is stable under natural conditions.?2?The 3D laser scanner was used to scan the rock mass structure of the right abutment slope and interpret the scan results.It was found that there are 3 sets of dominant joints in the rock mass of the slope,of which the two groups of structures face the steep slope outward,probably threatening the slope stability.Meanwhile,a certain probability model is used to estimate geometric parameters such as trace length and crack density of the discontinuities.?3?The FLAC^3D numerical simulation and the limit equilibrium method are chosen as the basis,the stability of the right abutment slope under different working conditions is studied.The research results show that when the optimized design scheme is adopted,the overall slope is stable and meets the design requirements.?4?Based on the characteristics of bank slope,a risk evaluation index system for the bank slope stability is established.Considering the weight and normal storage level,the risk analysis of slope stability is carried out based on the catastrophe theory.The risk values of slope stability before and after water storage are always natural state>original design plan>optimized design plan.?5?A maximum likelihood estimation method and a hyperbolic function are proposed to improve the catastrophe theory evaluation method,and the correlation coefficient method is used to verify the rationality of the method,making the risk evaluation results more in line with objective reality.