浅埋偏压连拱隧道洞口段施工技术研究  

Study on Construction Technology of Portal Section of Shallow Buried Eccentric Pressure Multi-Arch Tunnel

作　　者：李智 陈探 赵海斌 LI Zhi;CHEN Tan;ZHAO Hai-bin(Zhongjiao road and Bridge South China Engineering Co.,Ltd.,Zhongshan 528400)

机构地区：[1]中交路桥华南工程有限公司,中山528400

出　　处：《广州建筑》2022年第3期50-55,共6页GUANGZHOU ARCHITECTURE

摘　　要：黄山地区某连拱隧道的洞口施工段存在浅埋偏压的不利地质条件。为保障该项目的顺利开展,本文利用岩土工程有限元分析软件Midas建立三维实体模型,对有、无超前管棚支护两种条件下浅埋偏压连拱隧道洞口段施工过程进行模拟分析。计算得到了隧道在采用不同支护措施时各阶段围岩及支护结构的变形和应力变化情况。数值模拟结果表明在穿越破碎断层带浅埋偏压连拱隧道洞口段的施工中,采用超前管棚预支护技术可以较好地控制住围岩变形,保证开挖中和开挖后隧道的稳定性。最后,将现场3个监测断面的量测数据与模拟分析的结果进行了对比研究。现场监测数据证明超前管棚支护在浅埋偏压连拱隧道洞口段的施工中可以有效控制围岩的位移变形,避免不利工程地质灾害的发生。所得结论可为具有类似地质地形情况的隧道设计和施工提供技术参考。This paper conducted finite element analysis to ensure the safe production and construction of a multi-arch tunnel portal section in the Huangshan area under the adverse geological conditions of shallow buried eccentric pressure.A three-dimensional model is established using the geotechnical finite element analysis software MIDAS to simulate and analyze the construction process of the portal section of a shallow buried eccentric pressure multi-arch tunnel with or without advanced pipe shed support.The deformation and stress changes of the surrounding rock and support structure at each tunnel stage with different support measures were calculated.The results show that when the portal section of the shallow buried eccentric pressure multi-arch tunnel is through the fracture fault zone,the surrounding rock's deformation and the tunnel's stability during and after excavation can be effectively controlled by the advanced pipe shed support technology.Finally,the measured data of three monitoring sections in the field were compared with the calculated results.The field monitoring data proved that the adoption of advanced pipe shed support can effectively control the displacement and deformation of the surrounding rock in the construction of the portal section of a shallow buried eccentric pressure multi-arch tunnel.The conclusions obtained can provide technical references for designing and constructing tunnels with similar geological terrain conditions.

关 键 词：隧道工程 浅埋偏压 连拱隧道 数值模拟 变形支护 

分 类 号：U45[建筑科学—桥梁与隧道工程]