Relying on the shield tunnel project in the Chuang-Ju section of Foshan Metro Line 3,the surface settlement and tun-nel deformation under different reinforcement methods were obtained by numerical simulation,and the deformation law of the shield when crossing the full-section soft soil layer was studied.A set of suggestions for shield tunnel safety crossing reinforcement is pro-posed,and the simulation results are verified by combining with the field measurement.The research shows that when the shield is ad-vancing in the full-section soft soil stratum,the surface settlement,tunnel vault settlement and horizontal convergence value all in-crease continuously,which mainly occur when the shield passes through and after the shield tail segment is protruded,and it is also the main scope of action of pre-reinforcement;the impact of the leading tunnel on the surface settlement is greater than that of the trailing tunnel;when the shield passes through the unreinforced soil layer,the maximum values of surface settlement,tunnel vault settlement,and horizontal convergence are 27.7 mm,14.28 mm,and 10.57 mm,respectively.The deformations of the pre-grouting reinforcement are 57.0%,66.6%,and 61.0%of the unreinforced ones,respectively.When the triaxial stirring piles are used for pre-reinforcement,the deformations are 32.1%,48.5%,and 43.0%of the unreinforced ones.The pre-reinforcement can effectively control deformation,and the deformation control of the triaxial stirring pile is better than that of the advance pre-grouting reinforcement.When the ground envir-onment in the shield tunnel is complex and the ground reinforcement conditions are not available,it is recommended to use advance pre-grouting reinforcement to control the surface settlement and tunnel deformation.
关键词
全断面软土/盾构掘进/预加固方案/数值模拟/变形控制
Key words
full-section soft soil/shield tunneling/pre-reinforcement scheme/numerical simulation/deformation control
维普
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