Model Test of Constructing Shield Tunnel under Large Underground Structure

A 3D model test was carried out to investigate the interference when a metro tunnel is excavated with the shield method under an existing underground structure, the Xuanwuhu tunnel in Nanjing City. The experimental results showthatthe construction of the shield tunnel has a slighteffect on the Xuanwuhu tunnel is and large deformation to lead to the“excursion”of the Xuanwuhu tunnel does not occur. Under the conditions of setting uplife piles and reinforcing the ground below the Xuanwuhu tunnel, the additional deformations and internal forces are obviously reduced. In addition, the settlement of ground is small, so pavement structures can not be destroyed. Finally, to compare with the experimental result FEM(finite element method) was used. The numerical simulation result shows that both the Xuanwuhu tunnel and the shield tunnel are safe during the construction of the shield tunnel, and special measures are needed.