Study On The Formation Mechanism And Influence Factors Of Slump Shear Zone Between Unslided Anti-sliding Piles

With the rapid development of our country's economy,engineering construction has been rising.As the most common geotechnical engineering: deep foundation pits and high slopes,there are more and more in our country today.While we have made progress in these projects,more and more problems have emerged,such as the instability of foundation pits and slopes,landslides,and other problems.Collapses,and mudslides have also occurred from time to time.Anti-sliding piles,as a retaining structure with simple construction,strong anti-sliding ability,small disturbance to the slope body and high safety reserve,have been widely used in China in recent years,especially in the field of geotechnical engineering.However,the research on anti-sliding piles has not stopped for many years,but most of them are focused on the optimization design of anti-slide piles.The soil arching effect has been studied from time to time.In terms of soil stability,this is especially relevant.The study on the stability of soil between antislide piles is rare.Therefore,in this paper,the non-baffled anti-slide pile is taken as the research object,the theoretical analysis and numerical simulation are combined,and the localized shear zone is taken as the entry point to theoretically study the mechanism of landslide failure between piles,analyze its gradualness.At the same time,the three-dimensional distribution characteristics of the sliding surface of the soil between piles are summed up,combined with the strength reduction method,and the four factors of soil cohesion,internal friction angle,free surface width and height of the free surface are discussed.The effect of soil stability between piles,and then based on the experimental results of the current study,the results of theoretical and simulation analysis were compared with the analysis.The following main conclusions are drawn:(1)The slippage and destabilization of the soil between unbaffled antisliding piles can be effectively simulated by FLAC3D,and the collapse of the soil between piles is a gradual failure process.In this process,it will be accompanied by local The appearance of shear bands,and the localized shear bands have a certain width,are first formed near the free surface of the pile bottom,and then develop at a certain inclination angle along the soil upward until it penetrates to the surface of the soil,forming a continuous The sliding surface,then the soil between the piles will slide along the sliding surface and destabilize,and the shear band has a certain three-dimensional distribution in space,its intersection with the horizontal plane is parabolic,and the intersection with the vertical plane is approximately Number spiral,and when it develops to the soil surface,it is almost perpendicular to the horizontal;(2)In this paper,FLAC3D software is used to simulate the formation and development of the localized shear zone between piles,further study the mechanism of the slump instability of soil between piles,and determine the three-dimensional distribution characteristics of the sliding surface,combined with the strength reduction method,Calculate the stability coefficient of soil between piles,and systematically analyze the stability of the soil between piles;(3)From the perspective of soil strength and boundary constraints,this paper selects the four factors of soil cohesion,internal friction angle,free surface width,and height of free surface,and uses the single factor variable principle to discuss and analyze these four factors.The formation and distribution of soil shear bands between piles,the three-dimensional distribution characteristics of the sliding surface,and the influence of the soil stability between the piles.