Study On Group Anchor Effect In Slope Reinforcement With Prestressed Anchor Cable

In recent years,with the rapid development of national transportation infrastructure,the construction of highways and railways inevitably requires slope excavation.It is very important to ensure the safety and stability of slopes.The prestressed anchor cable structure has been widely used in slope reinforcement projects because of its economic,safety and convenient construction characteristics.In the construction and application of prestressed anchor cables,there are often serious losses of anchoring force due to different reasons,which require secondary reinforcement.However,when the secondary anchor cable is reinforced and prestressed and reinforced,the addition of new anchor cables sharply reduces the distance between the new and old anchor cables.In the case of small spacing,the stress between the group anchors is superimposed on each other in the rock and soil,increasing The displacement of the anchor cable and the anchoring force are reduced,so that the anchor effect of the new anchor cable is greatly reduced under the influence of the existing anchor cable.This is the so-called group anchor effect.Therefore,this article will further study the mechanism and key influencing factors of the group anchor effect in response to this phenomenon,and then apply the research results to the actual engineering project to solve the problem of strengthening the new anchor cable and ensure the safety and stability of the slope.At present,the research of prestressed anchor cable reinforcement mainly focuses on the relationship between stress and strain under the influence of different anchorage length factors.The length of the anchorage section is increased to ensure the reinforcement effect,but there are few studies on the arrangement of anchorage cable spacing.Therefore,through the study of relevant literature,this article will start from the problem of the mechanism of the anchoring section,focusing on the preliminary study of the group anchor reinforcement problem caused by the arrangement distance of different anchoring sections.Firstly,the load-displacement relationship of the anchorage section is analyzed,and the shear stress and shear displacement distribution of the anchorage section are analyzed by the three-stage shear-slip curve model.The non-uniform distribution of stress in the anchorage section is obtained through case calculation.For group anchor reinforcement,the shear stress of the anchor section of the central anchor cable should also consider the superimposed influence of the surrounding anchor cable stress,so the superimposed additional shear stress of the surrounding anchor section to the central anchor is solved by the Mindlin solution distribution model of the stress in the semi-infinite elastic body,And then derive the group anchor effect coefficient method.The numerical simulation software was used to perform pull-out simulation analysis on the single anchor,which verified the conclusion of uneven distribution of stress in the anchoring section.On this basis,the stress and displacement of the anchoring section under different spacings of the group anchor reinforcement were simulated and verified.This paper puts forward the rationality of the calculation theory of group anchor effect coefficient.Finally,relying on the specific engineering project,the phenomenon of group anchor effect between the new anchor cable and the existing anchor cable is analyzed and analyzed using the group anchor effect related theory.