高速铁路单线盾构隧道装配式隧底回填结构设计研究

Research on Fabricated Bottom Backfill Structure Design of Single Line Shield Tunnel in High-speed Railway

为提高单线盾构隧道隧底回填的施工进度和施工质量,并解决隧底回填现浇施工中存在的与联络通道施工干扰大、交叉作业、施工组织安排及洞内物料运输组织困难等技术问题,以某高速铁路单线盾构隧道为工程依托,对装配式隧底回填结构进行深入研究。结合具体工程技术条件,借助盾构工法机械化施工的优势,对隧底回填分块预制、整块预制、整块预制+两侧布设纵梁3个方案进行综合比选分析,并对选用方案在工程实施中进行验证。研究结论:隧底回填整块预制+两侧布设纵梁结构形式能够提高隧底回填的整体性和抗变形能力;可以实现隧道回填与盾构掘进及管片拼装同步实施,能够提高隧底回填施工质量和施工效率,改善隧底回填施工环境,提高盾构隧道的综合施工进度。

In order to improve the construction progress and quality of the backfill at the bottom of single-line shield tunnel and solve the problems such as cross operation with the construction of connected aisle,construction disturbance,construction organization and material transportation in tunnel,fabricated bottom backfill structure is studied based on the shield tunnel of a high-speed railway.In combination with specific engineering and technical conditions and the advantages of mechanized construction by means of shield method,a comprehensive comparative analysis is carried out on the three schemes of sub-block prefabrication,block prefabrication,block prefabrication and longitudinal beams on both sides of the tunnel backfill.And the selected scheme is verified in the implementation of the project.Research concludes that the block prefabrication and longitudinal beams on both sides of the tunnel backfill can improve the integrality and deformation resistance of the tunnel backfill,fulfill simultaneous construction of tunnel backfill,shield tunneling and segment assembling,enhance construction quality and efficiency,improve construction environment and speed up comprehensive construction progress.