Research on Construction Mechanical Behavior of Large-Scale Comprehensive Renovation and Performance Improvement of Operating Subway Station

To improve the overall performance of the subway station, Shenzhen Huangmugang transportation hub project needs to comprehensively renovate a long wall of 456.7 m of the operating subway station on three floors of the basement. In order to ensure operational security, a three-dimensional incremental finite element method was applied to study the construction mechanical behavior of the large-scale comprehensive renovation of the operating subway station. The results show that:1) The excavation of adjacent foundation pits in the existing station leads to the increase in the mid-span moment of the roof and baseboard, the moment of the frame column, and the horizontal displacement of the station. Therefore, it's necessary to optimize the support scheme of adjacent foundation pits to control the internal force and deformation of the existing structure. 2) The precipitation in the existing station can decrease the increment of the mid-span moment of the baseboard and the axial force of temporary columns. 3) As the layer number and span in the comprehensive existing side wall opening increase, the internal force and deformation of the existing station significantly improve. In addition, the increase in moment and deformation of existing structural plates can be decreased effectively by setting up temporary columns for pre-support. 4) In order to control the stress and deformation of the existing station, the scheme featuring precipitation and the establishment of temporary columns for renovation is relatively optimal.