Numerical Simulation Study of Double-Line Shield through Cutting Group Piles

The case of direct cutting of obstacle piles by shield tunneling frequently appears in the project, and it is very important to study the construction impact of shield cutting piles to ensure the quality and safety of tunnels and existing structures. Relying on the Shaoxing Metro Line 2 crossing underground passage pile group project, the finite element numerical simulation method is used to analyze the influence of the double-line shield tunnel cutting pile group on the formation and existing structure, and the influence of MJS reinforcement range on the deformation of the existing structure is explored. The results show that: The lower residual pile floats up after the shield is cut, and the upper residual pile and the rest of the pile foundation have obvious settlement. The truncated pile foundation has obvious tensile stress, with a maximum tensile stress of 1.23MPa. The MJS reinforcement can reduce the channel settlement and the lateral deformation of the pile foundation caused by shield excavation. With the increase of MJS reinforcement range, the channel settlement decreases significantly. Among them, the channel settlement is reduced by more than 38% after the MJS reinforcement under the tunnel, and the channel settlement is reduced by more than 48% after the MJS reinforcement around the tunnel.