Research On The Impacts Of Existing Subway Station During Underpass Of Tunnel

Along with booming development of the underground space projects for the city, urban subway transport projects welcome a peak for development. The technical problems for geotechnical engineering will also emerge for existing stations during underpass of newly-built subway tunnels. During construction process, the secondary disturbance of newly-built subway tunnels to surrounding stratum will generate new transformation and additional internal force for the existing station structures. In order to achieve design concept of safety, economy and environmental protection of subway tunnel projects, it is quite essential to understand the influence to existing subway station structure during underpass construction of subway projects.This article mainly analyzes numerical modeling and construction excavating procedures via Midas GTS finite element analytic software, and the background is Chongqing North Station of underpass of No. 3 Chongqing Subway Ring Line. The research is mainly about influences to settling volume and structural internal force of the stations during excavation of subway tunnels. The main achievements are as follows:①Analyze influence and deformation principle to existing subway stations by underpass project, influence to underpass tunnels by interlayer soil, and set up flexible foundation beam structure of underpass subway tunnel from direction of rock and soil mechanics.②Analyze and compare with common construction method of subway tunnels, combine with specific situation of Chongqing North Station project, and select reasonable construction scheme to analyze.③Take Chongqing North Station of underpass rail transit No. 3 of Chongqing North Station South Plaza Subway Ring Line as project background, calculate numeric modeling influenced by deep foundation pit to underpass subway station tunnel via Midas-GTS to set up three-dimensional solid model, and obtain influence feature and regularity of structural deformation influenced by deep foundation pit to underpass subway tunnel.④Use PKPM to conduct internal force checking calculation for Chongqing North Subway Station of Rail Transit Line 3, and analyze structural internal force for beam and column of the station.⑤Designed plan of Chongqing North Station of underpass rail transit No. 3 of Chongqing North Station South Plaza Subway Ring Line through calculations on structural displacement and structural internal force, confirm the feasibility for.