关键词:

盾构接收, 接收端主体结构, 施作时机, 地表沉降, 围护桩变形

Abstract: To explore the influence of shield tunnel receiving on ground settlement, retaining pile, and structural end sidewall deformation under different construction timings of the station′s main structure of the receiving end, a case study is conducted on the actual situation of the shield tunnel receiving construction project in a section of Xi′an metro line 14. The finite element numerical simulation method is employed to analyze the ground settlement and pile deformation of the shield receiving end under various construction timing conditions (i.e., after the completion of the bottom plate, the middle plate, and the roof) when the shield is received. On this basis, the influence of the change of the axial force of the steel support at different positions on the displacement and deformation of the shield during receiving is further studied, and the verification is carried out in combination with the field data. The research results show the following: (1) After the completion of the midslab construction of the main structure at the receiving end of the station, the shield receiving has the least impact on the surrounding surface settlement and the deformation of the retaining piles. The maximum surface settlement is located above end tunnel portal, and the horizontal displacement occurs to the pile body and it develops toward free face displacement. (2) The change of axial force of the first and second supports of the retaining structure has a great influence on the surface settlement and the deformation of the retaining pile after shield receiving, and the surface settlement and the lateral deformation of the retaining pile significantly reduced with an increase in the support axial force. (3) The axial force can be rationally increased to control the surface settlement and retaining pile deformation.

Key words: shield receiving, main structure of receiving end, construction timing, ground settlement, retaining pile deformation