Study On The Impact And Settlement Control Technology Of Shield Tunnel Through Existing Buildings

When using shield method for subway construction,it is difficult to completely avoid the existing buildings.During shield construction process,the tunnel may cause severe land subsidence,and affect the buildings’ safety.According to a tunnel project in Wuxi Metro Line3,which starts from a feeble confined water layer and crosses existing structures,this paper uses means such as theoretical calculation,numerical simulation and on-site settlement monitoring,to study settlement rules during shield construction and put forward protective technical measures for the existing structure.Some conclusions have certain practical application for construction safety.The main work are as follows:(1)On-site monitoring scheme is put forward,and monitoring data are statistically analyzed.Regression analysis method is used to study land subsidence and results shows empirical formula meets the monitoring data well;(2)The finite element numerical software ABAQUS is used to establish soil and structure’s three-dimensional numerical model.Deformation of the soil is analyzed to study settlement rules.Vertical stress and deformation of structure’s prisms are analyzed to study the disturbance of structure,which caused by the construction of tunnel.(3)The setting basis of tunneling parameters is studied based on the monitoring data.In order to guide the setting of grouting parameters,relationship between shield tunneling parameters and soil deformation is studied.(4)Soil reinforcement at the launching end of shield machine is studied.Contrast before and after reinforcement is studied through the numerical simulation.To pass through the building safety in Wuxi Metro Line 3,both shield parameters’ optimizing and soil reinforcement treatment is used and studied.