Law Of The Impact Of Ningbo Urban Rail Shield Construction On The Changing Surround Geotechnical Environmental

Construction Shield is an important city tunnel construction method.It has arelatively small impact on the ground and good stability advantages compared withother methods of tunnel construction. However, using construction shield will stillinevitably disturb the soil around, and consequently, change the surrounding soilenvironment.This paper’s statistical analysis is based on observation data of typical interval of Iand II line of Ningbo rail transit. The author summarized the lateral surface subsidencelaw and longitudinal settlement law of metro shield excavation in Ningbo unique softsoil environment.Performed on selected intervals deep soil subsidence and horizontaldisplacement monitoring when the shield excavation. Analysis the monitoring data,sowe can determine the sphere of influence deep and three-dimensional sphere ofinfluence.Fitting the measured surface subsidence curves of typical range,get transversesubsidence prediction formula and vertical subsidence prediction formula when Ningborail transit Shield Construction,and compared with typical peck formulas and Sagasetalongitudinal settlement formula results.Comparison of the results illustrate the proposedsettlement prediction more accurate formula applicable for Ningbo rail transit project.Numerical simulation model of shield excavation established by using ANSYS ofDP.We also analyzed the shield excavation’ influence in surrounding environment bycomparing the simulation results and measured results.So,we can not only confirm thevalidity of the numerical simulation of ANSYS，but also can we determine the range ofmodel parameters under different soil environment.