Impact of Lateral Pipe Curtains on Land Subsidence in PBA Metro Station

Abstract

[Objective] Shallow-buried metro stations constructed by PBA (pile-beam-arch) method are prone to significant strata settlement. Though lateral pipe curtains are convenient for construction, the optimization of their parameters for controlling land subsidence remains unclear, necessitating further in-depth research. [Method] Based on Jinan Metro R4 Line Olympic Sports Center Interchange Station project, numerical simulation and field monitoring are employed to analyze the influence of the stiffness, restraint length, and spacing of the lateral pipe curtain on land subsidence. [Result & Conclusion] Under the influence of lateral pipe curtain, the excavation sequence of surrounding tunnels first then internal tunnels resulted in the minimal final land subsidence. The greater the stiffness of the lateral pipe curtain, the smaller the land subsidence, with little impact on land subsidence when the stiffness increases to five times its original value. Increasing the restraint length of the lateral pipe curtain has a certain effect on land subsidence, though the impact is not significant. The lateral pipe curtain spacing has a more considerable effect on land subsidence; when the lateral pipe curtain spacings are large, their load-bearing capacity decreases significantly, weakening their support role in the strata.

Keywords

• metro
• station
• pba method
• lateral pipe curtain
• land subsidence