Study On Settlement Law And Control Method Of Soil Layer During Subway Tunnel Construction Under-Passing Urban Road

In recent years,the construction of underground rail transportation in our country has rapidly developed.And lots of projects,in which newly-built tunnels construct underneath the existing road,are springing up.The tunnelling project with numerous uncertainties is difficult to construct and has high requirements to stratum settlement,and easy to endanger the construction safety as well as Traffic Safety of existing road.Therefore,this problem is widely concerned by domestic and foreign scholar.Because of above reasons,based on the engineering of Shenzhen subway line 7 passing underneath the North-cycle road,the essay,with theoretical arithmetic method,numerical simulation method and monitoring analysis,researches on deformation law and controlling method of settlement caused by subway tunnel constructing under existing municipal road.And finally gets conclusions as following:(1)By utilizing Pearl Curve,present 3-D time-space forecasting model for stratum deformation in tunnel construction,and expand its applied range to double-track tunnel.Derive general calculation formula for undercrossing process between subway tunnel and existing road through equivalent soil column method.(2)Based on the engineering of Shenzhen subway line 7 passing underneath the North-cycle road,the essay propose specific instance of double-track tunnel passing underneath existing municipal road,and make contrastive analysis between calculation result and field monitoring data.(3)Based on field geological conditions and construction design,set up 3-D numerical model to execute finite-difference computation.And make analysis of stress and strain towards calculation result of numerical model.Moreover,based on fluid-structure interaction module,analyze the pore pressure variation and seepage law.And also research on the influence relation caused by change of space between twin tunnels.Eventually,summarize common surrounding rock reinforcement methods,and optimize advance reinforcement measures in advance through numerical simulation.Make further discussion on advance reinforcement measures.