Analysis of Influence of Shield Construction on Ground Deformation under Different Driving Force of Jack

Improper shield construction parameters will cause excessive ground settlement and ground deformation, resulting in safety accidents and economic losses.In this paper, the tunnel project between Wanqingsha Station and Hengli Station of Guangzhou Rail Transit Line 18 was taken as the engineering background, and MIDAS/GTS NX finite element software was used to change the thrust parameters of cutterhead top.The surface subsidence change and stratum deformation law caused by shield tunneling were studied, and the causes of soil deformation were analyzed combined with the actual construction process.The results show that the surface soil settlement occurs under the action of shield construction, and its shape conforms to the settlement curve proposed by peck.Under the small cutter head top thrust, the surface settlement of the construction condition is the smallest when the half tunneling ring number segment is completed.The peak value of surface subsidence decreases with the increase of the thrust of the cutterhead, but the decrease tends to be stable.The increase of the top thrust can reduce the collapse degree of the soil on the palm surface.The ground settlement trend under the thrust of 12000kN cutter head is basically consistent with the measured data, indicating that the numerical simulation results are more accurate and have certain guiding significance for tunnel construction.