Analysis Of Disturbance Influence Of Metro Shield Tunneling Through Existing Integrated Pipeline Corridor

With the development of China’s modernization process,the scale of subway construction in China has entered an unprecedented period of development.In the process of construction,the subway tunnel will not only be affected by the geological environment,hydrological environment and passing through the existing above-ground structures,but also have an impact on the existing underground structures and other underground planning projects.The subway shield construction passes through the city pipe corridor,and the soil disturbance causes the deformation of the pipe corridor structure,and even causes the destruction of the structure,which affects its normal use.In this study,combined with the engineering practice of shield tunnel construction in a certain section of Dalian subway,a three-dimensional numerical model of "pipe corridor-soil-tunnel" established by using the analysis method of numerical simulation and practical engineering.The influence of shield construction process of double-line tunnel on pipe corridor deformation,surface settlement and tunnel vault subsidence analyzed.The specific research contents are as follows:(1)The mechanism of soil settlement caused by shield construction summarized and summarized,and the interaction between the new tunnel and the existing pipe corridor in the process of shield construction theoretically analyzed.A three-dimensional numerical model is established by using FLAC3 D finite difference software combined with the practice of Dalian subway project to further analyze the influence of shield piercing process on the deformation of pipe corridor structure,and to study the surface settlement and the settlement deformation of newly-built tunnel.The results show that the settlement peak value of pipe corridor settlement is formed above the vault of double-line tunnel,and the settlement deformation has obvious superposition effect,and the deformation mainly occurs in the shield passing stage and shield tail gap stage.And the pipe corridor has a certain inhibitory effect on the surface subsidence above it and the vault subsidence near the underpass area.Finally,the simulation results and monitoring data are compared and analyzed to verify the rationality of the model analysis results.(2)The disturbance effects of different tunnel clearance,tunnel diameter,buried depth of pipe corridor,tunnel tunneling speed and grouting intensity on the construction of pipe corridor are analyzed,and the characteristics of settlement curves of the same group are compared.The effects of different factors on corridor settlement,surface settlement and vault subsidence are summarized and explored.(3)The grey correlation analysis method is used to calculate the grey correlation degree of the above five factors on the settlement deformation of pipe corridor,surface settlement and vault subsidence respectively,and the sensitivity of the factors is studied.Taking the settlement and deformation of existing pipe corridor as an example,the results show that the tunnel diameter and buried depth of pipe corridor have great influence on the deformation of pipe corridor,which should be considered in design and construction,so as to provide some reference and reference value for similar engineering background schemes.(4)According to the numerical simulation results,the failure reasons of pipe corridor are summarized,and combined with the field data and relevant engineering experience,the control measures of pipe corridor construction are put forward from two aspects: the active measures of shield construction parameter control and the passive measures of pipe corridor protection.