Analysis of Impact of Shield Tunnel Side-passing Construction on Adjacent Buildings in Suburban Railway Projects

Objective With accelerated urbanization, shield tunneling for suburban railways increasingly involves close-proximity side-passing of existing buildings, which can affect the structural safety of adjacent buildings. Appropriate protection measures should therefore be adopted.

Method Using the case of the Jiaxing–Fengnan Suburban Railway shield tunnel side-passing a nearby power distribution room, numerical simulations are performed to analyze the impact on the existing building under two conditions—without and with foundation pile reinforcement.

Result & Conclusion  When the distribution room foundation piles are not reinforced, the maximum settlement of the column foundation induced by the shield tunnel side-passing is 13.3 mm, and the differential settlement between adjacent column foundations is 0.73‰l, both within deformation control limits. When the piles are reinforced, the maximum column foundation settlement decreases to 2.5 mm, and the differential settlement reduces to 0.163‰l. Pile reinforcement significantly reduces the additional differential settlement caused by tunnel excavation. Prior to shield tunnel side-passing construction, an appropriate pile foundation reinforcement scheme should be implemented for buildings in close proximity.