非等大断面小净距地铁隧道施工方案分析及优化  

Analysis on and Optimization of Construction Scheme of Closely-spaced Metro Tunnels with Different Cross-section Dimensions

作　　者：丁改改[1] 姜海[1] 孔祥兴[1] 

机构地区：[1]中交第一公路勘察设计研究院有限公司,陕西西安710075

出　　处：《隧道建设》2014年第8期715-720,共6页Tunnel Construction

摘　　要：为同时满足双线行车和右线停车线扩大断面的功能需要,西安地铁一号线枣园北路站—汉城路站区间采用非等大断面小净距黄土地铁隧道。针对断面不等大、盾构法与新奥法组合施工方案、小净距黄土地铁隧道的特点,进行了左线小断面盾构法、右线大断面双侧壁导坑法或CRD法双线依次先后贯通3种施工方案的数值模拟与比选分析。计算结果表明,与先贯通小洞、后开挖大洞的方案相比较,采用先新奥法贯通大断面隧道、后盾构法掘进小断面隧道的施工方案对围岩扰动较小,能更有利于控制地表变形;双侧壁导坑法较CRD法虽更能充分体现围岩的自承能力,有效发挥初期支护的承载能力,提高二次衬砌的安全储备,但若将先贯通的大断面隧道施工方案由双侧壁导坑法改为CRD法,可在确保工程安全的前提下降低施工成本,并加快施工进度,顺利地完成隧道建设。A portion of the running tunnel from Zaoyuan North Road Station to Hancheng Road Station on No.1 line of Xi’an Metro is designed as a closely-spaced Metro tunnel with different cross-section dimensions.The parallel tunnel tubes have such features as different cross-section dimensions,dual construction methods （shield tunneling method and NATM）and small spacing.Numerical simulation is made on the construction of the left small cross-section tunnel tube by shield tunneling method and the right large cross-section tunnel tube by double side drift method and CRD method. The calculation results show that：1 ）Compared to the scheme that the left small cross-section tunnel tube is broken through before the right large cross-section tunnel tube is excavated,the scheme that the right large cross-section tunnel tube is broken through by NATM before the left small cross-section tunnel tube is bored by shield has smaller disturbance on the surrounding rock mass and is more helpful for ground deformation control;2）Compared to CRD method,double side drift method is more helpful to making full use of the self-support capacity of the surrounding rock mass,is more helpful to making full use of the load-bearing capacity of the primary support,and is more helpful to improving the safety reserve of the secondary lining;however,if CRD method is adopted for the right large cross-section tunnel tube,which is broken through before the left small cross-section tunnel tube,the construction cost can be reduced,the construction progress can be improved and the tunnel can be constructed successfully under safe conditions.

关 键 词：地铁隧道 非等大断面隧道 小净距 盾构法 新奥法 方案比选 监测 

分 类 号：U45[建筑科学—桥梁与隧道工程]