Influence Of Layout Of Double-Row Anti-Slide Piles With Anchor Cable On Thrust Distribution And Pile-Soil Interaction

At present,due to the design of the anti-slide piles of double-row anchor cables,there is no clear design specification.The thrust distribution of the landslide thrust loads in the front-row and back-row anti-slide piles can only be judged by the experience.In order to research the distribution ratio of landslide thrust load between front-row and back-row piles,this thesis relying on a slope reinforcement project in Sichuan Province establishes the finite element model to analyze the double-row anti-slide pile load under different design parameters.Based on above,the theoretical calculation method of double-row pile load under corresponding working conditions is proposed.The main work and research results of this thesis are as follows:1)This thesis uses the limit element method to analyze an actual anti-slide pile project,comparing the finite element calculation results with the actual engineering design results.It finds there is a certain gap in the internal force of the pile body.In order to further verify the results,the internal force of the anti-slide pile is reversed by the monitoring data of the anti-slide pile reinforcement of the project.The monitoring data confirms the finite element calculation result is accurate.So the load distribution method in the original project is to be discussed.2)The study found that the larger the row spacing between piles,the smaller the load proportion of the back-row pile,and the greater the load on the front pile.When the row spacing is greater than a certain value,the proportion of the load shared by the back-row piles increases with the increase of the spacing,and the proportion of the load shared by the front pile decreases with the increase of the spacing.When the row spacing is less than a certain value,the proportion of the shared load of the back-row piles decrease with the increase of the spacing,and the proportion of the load of the front-row pile increase with the increase of the spacing.The layout of the pile and the application state of the anchor cable pre-stress after the anti-slide piles have no obvious influence on the load distribution of the piles in the front-row and back-row of the anti-slide piles.3)It is found that when the row-spacing is less than a certain value,the soil arch around the anti-slide pile is not completely formed.The landslide thrust loading on piles can transmit to the soil before the pile.When the row-spacing is greater than a certain value,there is obvious plastic strain in the soil behind the back-row piles.The direction of the max principal stress of the soil in the plastic zone is deflected,and the stress flow is connected to the arch.The soil arch is completely form.At this time,the soil in front of the pile has no support for the pile,and the back-row piles will not transmit the landslide thrust forward.4)The calculation method of double-row anti-slide piles under different row working conditions is proposed.When the row-spacing is greater than a certain value,the residual sliding force behind each pile can be used as the thrust load by using the folding line sliding method after the double rows of piles respectively.When the row spacing is less than a certain value,the joint effect of pile and soil needs to be considered.The pile and soil can be assumed to be an elastic body.The calculation method of the thrust distribution can be obtained by the coordination equation of pile-soil deformation.Using this method,the load of the pile before and after the project is calculated,and the calculation result is similar to the finite element calculation result.