Study Of Design On Assembled Pile-anchor Supporting Structure System

With environmental conscious of the country enhanced,foundation pit supporting technology has become more and more skillful,traditional pile-anchor supporting structure system was widely used,the material of traditional pile-anchor supporting structure system is mostly reinforced concrete,the structure system has some the disadvantages such as heavy and large structure,long construction period and poor economy.However,the material of assembled pile-anchor supporting structure system is the section steel,the structure system has advantages of good the mechanics and mechanical installation performance,its purpose is rapid construction and reuse,resulting in lower support cost.Therefore,the traditional pile-anchor supporting structure system was gradually replaced by the assembled pile-anchor supporting structure system.In the first,research findings of the traditional and assembled pile-anchor supporting structure system was analyzed summarily.Based on the existing results,the thesis proposes an assembled pile-anchor supporting structure system,which followes the concept of low carbon and environmental protection and ensures the safety of foundation pits and aimed at reuse,and expoundes the construction process of the scheme,the concept of the supporting scheme,the standardized design scheme,and the economic advantages of the supporting scheme.Secondly,the numerical model of the assembled pile-anchor supporting structure was established by using ABAQUS finite element software for simplified and realistic situations,the internal force and deformation of the supporting structure system,the overall stability,the deformation laws of the foundation pit,the soil pressure behind the retaining slab,the force and deformation of the retaining slab were researched and analysed,the main research contents and conclusions are as follows:(1)Base on the numerical model of the assembled pile-anchor supporting structure system of simplification,the internal force and deformation laws of the piles and the overall stability of the supporting structure system were analysed.The results show that it is safe and feasible to the assembled pile-anchor supporting structure system.(2)Based on the characteristics of the two pit projects and Its geological conditions,the process of excavation and supporting of the foundation pit was studied and analysed by ABAQUS.The results of the internal force and deformation of the supporting pile and displacement of the pit for each working condition were obtained.After comparing the two results,the results show that it is extremely useful to the applicability of the assembled pile-anchor support structure system.(3)The internal forces and deformation of the supporting structure were researched and analysed by changing certain elements,such as the pile type,the pile spacing and the magnitude of the prestress.The results show that the internal force and horizontal displacement of the supporting pile will decrease with the increase of pile type,the pile spacing reduce and the increase of the prestress.(4)The soil pressure behind the retaining slab was studied and analysed by the finite element method,the results show that the soil pressure behind the slab tends to a certain value with the depth of the pit increases.