山岭隧道软弱围岩工程地质特性及施工对策

山岭隧道软弱围岩工程地质特性及施工对策
张健儒
(中铁隧道集团有限公司,河南洛阳 471009)
摘要:如何在软弱围岩地质条件下安全快速地修建长大隧道是当前隧道工程界面临的重要课题之一,尤其是当隧道穿越高地应力软弱围岩时,常常形成大变形等地质灾害,严重影响施工安全和进度。通过对软弱围岩工程地质特性、软岩隧道变形机制及变形控制基本理念进行分析,并结合相关工程实例提出软岩隧道支护结构安全稳定性评判标准及施工应采取的相应对策。认为:1)软弱围2)岩隧道由于支护参数、施工方法选择不当,支护结构强度和刚度不足以抵抗较高的围岩压力时,往往会出现结构大变形和破坏;软岩地段初期支护承受施工期间全部荷载,二次衬砌需承受后期围岩流变产生的荷载,软岩隧道衬砌应通过增设钢筋、加大厚度等方式增加结构强度;3)超前支护与加固技术可提高围岩的自承能力并减小作用在支护结构上的荷载,且应当成为当前软弱围岩隧道施工技术研究的发展方向;4)在高地应力山岭隧道方面,应进一步开展施工阶段地应力测试,以利于针对性地选择施工方法和支护参数。
关键词:山岭隧道;软弱围岩;变形机制;高地应力;施工对策DOI:10.3973/j.issn.1672-741X.2014.08.007
中图分类号:U45 文献标志码:A 文章编号:1672-741X(2014)08-0749-05
EngineeringGeologicalPropertiesofSoftSurroundingRocksof
MountaincrossingTunnelsandConstructionCountermeasures
ZHANGJianru
(ChinaRailwayTunnelGroupCo.,Ltd.,Luoyang471009,Henan,China)
Abstract:Safeandrapidconstructionoftunnelsinsoftsurroundingrocksbecomesmoreandmoreimportant.Especially,seriousdeformationmayoccur,whichmaywhentunnelingthroughsoftsurroundingrockswithhighgroundstressjeopardizetheconstructionsafetyandtheconstructionprogress.Inthispaper,theengineeringgeologicalpropertiesofsoftsurroundingrocks,thedeformationmechanismsoftunnelsinsoftsurroundingrocksandthebasicdeformationcontrolconceptsareanalyzed,andthecriteriaforthesafetyandstabilityofthesupportstructuresoftunnelsinsoftsurroundingrocksandtheconstructioncountermeasuresareproposed.Conclusionsdrawnareasfollows:1)Duetotheimpropersupportparametersandconstructionmethodsadopted,thestrengthandrigidityofthesupportstructurecannotresistthe;2)Insoftsurroundingrockhugesurroundingrockpressureandthereforeseriousdeformationandfailuremayoccursection,theprimarysupporttakesalltheloadsduringconstruction,thesecondaryliningneedstotaketheloadscausedbythedeformationofthesurroundingrocksinthelaterstage,andtheliningofthetunnelinsoftsurroundingrocksshouldbestrengthenedbymeansofaddingsteelbarsandincreasingtheliningthickness.3)Advancesupportandreinforcementcan,improvetheselfsupportcapacityofthesurroundingrocksandcanreducetheloadactingonthesupportstructurethereforetheadvancesupportandreinforcementshouldbethefocusofstudiesonconstructiontechnologiesoftunnelsinsoftsurroundingrocks;4)Formountaincrossingtunnelsinhighgroundstressarea,groundstressmeasurementshouldbefurtherimplementedsoastoselectproperconstructionmethodsandsupportparameters.
Keywords:mountaincrossingtunnel;softsurroundingrock;deformationmechanism;highgroundstress;constructioncountermeasure
收稿日期:2013-12-26;修回日期:2014-03-16
作者简介:张健儒(1973—),男,陕西陇县人,1996年毕业于西南交通大学,地下工程与隧道工程专业,本科,高级工程师,从事铁路隧道工程施工与技术管理工作。


