86
DOI:10.7672/sgjs2016190086
施工技术
CONSTRUCTIONTECHNOLOGY
2016年10月上第45卷第19期
三明铁路隧道三台阶法开挖施工围岩变形特征研究
胡守云1,2，吴廷尧1
（1.中国地质大学（武汉）工程学院，湖北武汉430074；2.中铁十六局集团有限公司，北京100018）
［摘要】结合三明铁路隧道工程，利用弹塑性理论和离散单元法的基本原理，建立了离散元程序UDEC数值计算模型，并通过实测数据对数值模型进行验证，三明隧道开挖施工过程数值模拟结果表明：①三台阶法开挖施工有效抑制了软岩隧道围岩的大变形，且竖向位移主要集中在隧道拱顶和拱底处，水平位移主要集中在隧道两侧拱脚处； ②受节理分布和断层的影响，隧道不同方向的位移场变形并不对称，同时隧道两侧拱脚处围岩的稳定程度相对较差，因此在施工过程中应加强拱脚稳定措施。最后将模拟数据与相应规范进行比较，进而对软岩隧道施工过程中
隧道围岩稳定性进行评价，从而为软岩隧道的安全施工提供了技术保障。【关键词］隧道工程；三台阶法；围岩；变形；施工技术
【中图分类号】U414
【文献标识码］A
【文章编号］1002-8498（201619-0086-05
Study onDeformation Characteristics of SurroundingRockinExcavation
ConstructionwithThree-stepMethodforSanmingRailwayTunnel
Hu Shouyun'.2,Wu Tingyao'
(1. Faculty of Engineering, China Uninersiy of Geosciences, Wuhan, Hubei 430074, China ;
2. China Railray 16th Group Co. , Lid. , Beijing100018, China)
Abstract : Combined with Sanming Tunnel engineering,using elastic-plastic theory and basic principles of discrete element method, discrete element UDEC numerical models were built. And the numerical model is validated by the measured data. Sanming Tunnel excavation process simulation results show that: Three-step excavation construction effectively suppresses the large deformation of surrounding rock of soft rock tunnel,and the vertical displacement is mainly concentrated in the vault and arch bottom, on both sides of the arch foot horizontal displacement is mainly concentrated in the tunnel; ② With the influence of the joint distribution and fault, tunnel displacement deformation in different directions is not symmetrical, and the stability of the tunnel surrounding rock on both sides of the two level is relatively poor, and therefore which should be strengthened in the construction process of the arch foot stability measures. Finally, compared simulated data with the appropriate specifications, and tunnel surrounding rock stability in soft rock tunnel construction is evaluated so as to provide technical support for the safe construction of soft rock tunnel.
Key words :tunnels ;three-step method;surrounding rock ;deformation ;construction
处于断层破碎带的隧道开挖及衬砌作业是隧
道工程施工中的重要环节，采用何种开挖方法并在开挖后及时施作初期支护关系到隧道的整体稳定性[12]，目前铁路隧道穿越断层情况较多，在软弱围岩条件下隧道三台阶法施工能够使初期支护尽早闭合，有利于开挖面的稳定和控制其结构变形及由
[作者简介］胡守云，高级工程师，博士研究生，E-mail；hushouyun@ 163.6
【收稿日期]月数据：【修订日期］2016-08-06
此引起的地面沉降。国内外学者对软弱围岩隧道开挖过程中围岩变形与控制技术进行了广泛研究，陈建锋、魏建军等应用工程实例探讨了隧道在软弱围岩条件下采用三台阶预留核心土法和三台阶七步法施工,有效控制了隧道围岩的大变形[34]；李文江、任建喜等基于FLAC有限差分软件分析采用台阶法施工过程中软岩隧道围岩的变形规律[5-]：韦秉旭等利用FLAC有限差分软件对软弱围岩条件下隧道采用台阶法和CRD法施工过程进行了数值模拟，分析了两种不同的开挖方式对隧道围岩稳定