Research On The Stability Of Large Excavation Slope Of Embankment And Optimization Of Anti-seepage Wall Parameter

Slope stability has always been a hot topic,and the seepage of groundwater is often the main cause of slope failure.The seepage movement of groundwater and the original stress field of rock and soil interact and influence each other,presenting a complex state of seepage stress coupling,making slope problems no longer a single stress field or seepage field problem.Based on the strength reduction method and the seepage stress coupling theory,this paper uses MIDAS/GTS finite element simulation analysis software to study the change of slope stability under three different working conditions,namely,no groundwater condition,seepage stress coupling condition and anti-seepage wall.On this basis,by optimizing the slope ratio of the anti-seepage wall and slope,while ensuring the safe and smooth progress of the project,optimizing certain parameters can achieve the goal of saving costs and time,and creating greater economic value.The main conclusions of this article are as follows:(1)The basic theories of strength reduction method and seepage stress coupling analysis are introduced,and the application of seepage stress coupling in MIDAS/GTS is realized.On the basis of the seepage stress coupling theory,slope stability analysis was conducted under three different conditions: no groundwater conditions,seepage stress coupling conditions,and adding anti-seepage walls.The safety coefficients of the slope under these three conditions were 1.47,1.18,and 1.53,respectively.When the slope undergoes seepage movement,under the coupling effect of seepage stress,the safety coefficient of the slope decreases significantly and the displacement of the slope body also increases significantly.The anti-seepage wall can effectively prevent the occurrence of seepage movement,and also serve as a certain retaining wall,effectively preventing lateral soil pressure on the water side,significantly reducing the displacement of the slope,and effectively improving the safety factor of the slope.(3)On site monitoring was conducted on the anti-seepage wall and excavation slope,and the monitoring results were generally consistent with the calculation results,verifying the rationality and scientificity of the MIDAS/GTS finite element software.(4)An effect analysis was conducted on the elastic modulus,Poisson’s ratio,and thickness of the anti-seepage wall.The results showed that the elastic modulus can effectively reduce the deformation of the anti-seepage wall and improve the safety factor of the slope;The variation of Poisson’s ratio has no effect on the deformation of the wall,but has a significant impact on the safety coefficient of the slope and is not nonlinear.There should be an optimal Poisson’s ratio in the middle;The thickness of the anti-seepage wall determines the deformation of the anti-seepage wall.Even if the displacement deformation difference between the two thicknesses is nearly 10 times,the anti-seepage wall still remains undamaged,retaining its original anti-seepage and retaining functions.However,the thickness of the anti-seepage wall has almost no effect on the slope safety factor.(5)The slope ratio has been optimized,and in practical engineering,the optimized slope ratio can be used to save excavation volume and shorten construction period,thereby achieving the goal of creating economic value.This article analyzes the stability of slopes under three different working conditions,and obtains the variation rules of slope stability under different conditions.Taking into account the impact of deformation pits on the anti-seepage wall and optimizing the slope ratio,the conclusions obtained can provide certain reference significance for similar slope excavation projects.