Study On Optimization Design Of Spillway High Slope Of The Qianping Reservoir

The slope stability of the spillway high slope of qianping reservoir is the key to control engineering construction.This paper is based on engineering geological survey and geotechnical strength experiment,the stability of slope is studied by numerical analysis and limit equilibrium method,firstly,the safety coefficient of slope is calculated by using the limit equilibrium method,then a numerical analysis is made for the typical profile of the slope,the displacement and stress distribution of slope are studied and Monte carlo reliability analysis which study the variety of working conditions of spillway slope stability,comprehensive integration of various methods is adopted,To carry out the the optimization design of spillway slope.The original design of the spillway slope is to use 1:0.5 slope of the inlet channel rock slope,the left bank has a total of 5 tracks.According to the stability analysis results of spillway slope,the slope of the slope can be increased appropriately,from the original design 1:0.5 to 1:0.4,reduce slope excavation.The original design anchor is 5m,diameter Φ 25,spacing @ 2 m x 2 m,the anchor can not slip through the slope instability slip surface,the length should be increased to 10 m,the anchor angle should be perpendicular to the slip plane.Two methods of rigid body limit equilibrium and numerical analysis can not only calculate the safety factor and slope displacement field of the slope,but also the stability of slope can be evaluated more comprehensively.In this paper,the stability of spillway under different working conditions is studied by means of limit equilibrium method,numerical analysis and reliability analysis.The safety factor of the original design of spillway high slope was 1.74,the safety factor of the optimized design scheme spillway is 1.61 after the excavation,compare the values of the two security coefficients,there is not much difference;after the high slope of the spillway was excavated,although the slope of slope excavation is improved under the optimization scheme,however,compared with the design scheme,the deformation of slope body is not significant,its maximum deformation value is not more than 5cm;the reliability index of the original design project spillway is 5.24,reliability index of the optimized design scheme spillway is 4.89,the results show that the optimal design scheme of slope excavation meets the requirements of slope design and the optimized scheme reduces the excavation volume and saves the project investment.