Analysis Of The Influence Of Metro Shield Tunneling Method On Existing Tunnels

With the rapid development of urban construction and traffic engineering in China,the problem of crossing different traffic lines has attracted great attention.Even with the development of engineering technology and Technology level and the accumulation of a lot of experience in actual cases,there are still many uncertainties in actual engineering construction due to different geological conditions,hydrological characteristics and the complexity of actual engineering crossing conditions and other reasons.Therefore,it is of corresponding significance to study the influence of soil displacement and structural deformation caused by new tunnel crossing existing buildings and structures And engineering value.Taking the newly-built double line subway in Suzhou as the research object,this paper mainly discusses the soil deformation and internal force variation of the surface and the existing tunnel in the process of shield tunneling,and analyzes the influence of different working conditions and influencing factors on the existing tunnel.The main research contents and achievements are as follows.(1)According to the existing geological survey report and design scheme,the reasonable soil layer and material parameters are selected,and the three-dimensional finite element model of the new shield tunnel under the existing tunnel is established by using the finite element software,so as to finely simulate the construction process of shield excavation removing soil and generating lining.(2)Based on the actual project,the influence of shield underpass construction on the existing tunnel and the upper surface under the two working conditions of reinforced and unreinforced soil at the bottom of the tunnel is compared and analyzed,and its deformation and internal force variation law are studied.From the analysis of numerical simulation,the deformation and internal force of the existing tunnel caused by the shield Undercrossing are greatly reduced after the soil at the bottom of the existing tunnel is reinforced,and the uneven deformation problem is obviously improved.(3)By changing the construction interval,horizontal interval,vertical interval and grouting pressure of the new tunnel,this paper discusses the deformation and internal force variation law of the surface and existing tunnel after the completion of shield construction,so as to provide certain reference value for related projects.