Influence Law of PBA Method New Station Closely Undercrossing Existing Station on Its Structural Deformation

Abstract

Objective A new station constructed with PBA method closely undercrossing existing station will influence the deformation of the latter′s structure. The influence law needs to be studied. Method Based on the project of Pingguoyuan Station on Beijing Metro Line 6 closely undercrossing the existing station, a finite element model is established by the GTS NX finite element analysis software, and its computing accuracy is verified through comparison with the actual monitored results. According to the calculation results of the finite element model, the impact of PBA (pile beam arch) method construction on the existing station is studied, and the influence of the existing station on land subsidence is analyzed. Result & Conclusion In the process of PBA construction, the construction stages that greatly affect the track structure and the building structure of the existing station are the guiding hole excavation and the second lining arch stages. The closer the construction is to the existing station, the smaller the land subsidence. When the monitoring sections are at the same location, the larger the existing station structure section, the smaller the land subsidence. With the same section size of the existing station, the closer to the excavation centerline of the new station, the greater the land subsidence value. The influence range of the existing station is related to the sectional size of the existing station structure.

Keywords

• metro station
• construction influence
• closely underpassing
• pba construction method