Study on the Influence Mechanism of Soil Deformation Induced by Shield Tunnel Construction

Abstract

The construction of shield tunnel will adversely affect the surrounding soil and is prone to safety accidents. This paper focuses on the problem of soil deformation induced by shield tunnel construction. Based on the theoretical mechanics Mindlin solution, the soil deformation caused by the frontal thrust, friction force and formation loss of the shield is linearly superimposed, and the accurate calculation formula of soil deformation caused by shield is derived in time and space. Relying on the finite element software Midas GTS NX, the three-dimensional dynamic simulation of soil deformation induced by the double-line tunnel was carried out, the law of stratigraphic deformation during the construction of the double-line tunnel was obtained, and the influence mechanism of different tunnel burial depths on the surrounding soil deformation was studied. Finally, it was proved that the settlement curves of the surface and soil layer during the continuous excavation and unloading of the double-line shield tunnel were consistent with the settlement curves of the double-line Peck, and the settlement extremes of the pilot tunnel were slightly larger than those of the latter tunnel.