大断面暗挖地铁车站交叉群洞施工顺序及关键工序研究  

Study on Construction Sequence and Key Working Procedures of Cross-Tunnel Groups in Large-Section Subway Stations Using Underground Excavation Methods

作　　者：赵志民[1] 涂怀宇 刘建峰 ZHAO Zhimin;TU Huaiyu;LIU Jianfeng

机构地区：[1]中国水利水电第五工程局有限公司,四川成都610066 [2]西南交通大学交通隧道工程教育部重点实验室,四川成都610031 [3]西南交通大学土木工程学院,四川成都610031

出　　处：《重庆建筑》2024年第9期49-55,共7页Chongqing Architecture

摘　　要：为探究大断面浅埋暗挖地铁车站交叉群洞施工力学特性并给出交叉风道最优施工方案,该文依托重庆地铁4号线玉带山车站隧道工程,利用三维数值模拟的方法建立车站交叉群洞的三维模型,研究了与主洞相交的两风道先后开挖顺序、风道各部全导洞开挖或挂2 m洞门处理对群洞结构稳定性的影响。研究结果表明,越靠近车站端头处隧道拱顶沉降值越大,施工过程中临时支护结构能有效控制隧道变形和受力;3号风道各部采用挂洞门处理时与全导洞开挖相比,能降低拱顶约1.3 cm的最大沉降,拱腰处结构安全系数最大增加了22%;先行施工3号风道与先施工6号风道相比6号风道周边围岩更为稳定,3号风道周边围岩塑性区延伸范围也更小;车站隧道底部两层台阶开挖、最终临时支护的拆除这两个工序引起的拱顶测点沉降增量最大,结构的安全系数也在这两个工序有较大幅度降低,为施工过程中的关键步序。To investigate the mechanical behavior of crosstunnel groups in large-section shallow-buried subway stations during excavation and propose the optimal construction scheme for intersecting air ducts,this paper relies on the Yudaishan Station Tunnel Project of Chongqing Metro Line 4.A three-dimensional numerical simulation model of the cross-tunnel groups in the station is established.The study examines the influence of excavation sequences of two intersecting air ducts with the main tunnel,and the impact of full pilot tunnel excavation versus hanging a 2-meter portal for each section of the air ducts on the structural stability of the tunnel groups.The results show that the tunnel crown settlement increases towards the end of the station.Temporary support structures effectively control tunnel deformation and stress during construction.When the hanging portal method is adopted for each section of Air Duct No.3 compared to full pilot tunnel excavation,the maximum crown settlement can be reduced by approximately 1.3 cm,and the structural safety factor at the haunch increases by up to 22%.Constructing Air Duct No.3 first results in more stable surrounding rock around Air Duct No.6 compared to constructing Air Duct No.6 first,and the plastic zone extension around Air Duct No.3 is also smaller.The two key procedures that cause the largest incremental crown settlement at measuring points and significantly reduce the structural safety factor are the excavation of the two-step benches at the bottom of the station tunnel and the removal of the final temporary support.These are the critical steps in the construction process.

关 键 词：大断面 地铁车站 群洞效应 力学特性 施工优化 浅埋暗挖 

分 类 号：U25[交通运输工程—道路与铁道工程]