半硬半软岩隧道塌方的力学特性及处理方法分析

由于蛟岭隧道出口横断面一半为硬岩,结构完整,而另一半为软岩,为风化岩层,且较为破碎,所以在隧道开挖时,硬岩一侧刚度较大,变形较小,自稳能力大;软岩一侧与之相反,遇水软化,流变性明显,所以在软硬岩交界面处,产生滑移,导致塌方,从而在软岩一侧采取了地表加固和掌子面管棚注浆的处理,形成了与硬岩接近的强度,使隧道周围形成一个承载环,并对处理段进行了监测, 监测数据分析表明处理后迅速达到稳定。

JournalofEngineeringGeology 工程地质学报 1004-9665/2009/17(2) 0263 05

半硬半软岩隧道塌方的力学特性及处理方法分析

喻 军 刘松玉 童立元

(东南大学交通学院岩土工程研究所 南京 210096)

*

摘 要 由于蛟岭隧道出口横断面一半为硬岩,结构完整,而另一半为软岩,为风化岩层,且较为破碎,所以在隧道开挖时,硬岩一侧刚度较大,变形较小,自稳能力大;软岩一侧与之相反,遇水软化,流变性明显,所以在软硬岩交界面处,产生滑移,导致塌方,从而在软岩一侧采取了地表加固和掌子面管棚注浆的处理,形成了与硬岩接近的强度,使隧道周围形成一个承载环,并对处理段进行了监测,监测数据分析表明处理后迅速达到稳定。关键词 半硬半软岩 隧道塌方 管棚 注浆 地表加固 蛟岭中图分类号:U452.1+1 文献标识码:A

MECHANICALCHARACTERISTICSANDTREATMENTMETHODOFCOLLAPSEOFTUNNELWITHHALF-HARDANDHALF-SOFTROCKSALONGITSTRANSVERSESECTION

YUJun LIUSongyu TONGLiyuan

(InstituteofGeotechnicalEngineering,TransportationCollege,SoutheastUniversity,Nanjing 210096)

Abstract TheJiaolingtunnelinconstructionencounteredtwotypesofrocksalongitstransversesection.Halfofthetunnelsectionishard-rockwhiletheotherhalfissoftrock.Thehardrockisintactandhasa40MPacom pressivestrength.Thesoftrockisweatheredandfracturedandhasacompressivestrength5MPa.Collapseatthesideofsoftrocktookplaceduringtheconstruction.Mechanicalcharacteristicsforthehardandsoftrocksandthecollapsereasonswereanalyzedattheportalofthelefttunnelline..Thencounterpartcollapsetreatmentswereem ployed.Forexample,surfacewithgroutingreinforcementandtube-groutingframewereexplained.Strengthofthetreatedsoftrockwasalmostequaltothatofhardrock.Bearingloopwasmadeupoftreatedsoftrockandhardrock.Atlastthetreatedzonewasmonitored.Itwasjudgedfrommonitoringdatathatthezonewasstablequickly.So,thistreatmentmethodisreasonableandeffective.Thebearinglooptheorycanbeusedtothehalf-hardandhalf-softrocktransverse-sectiontunne.lNewideainthepaperisthesuspensiontheoryapplicabletoboltingandgrouting-tubetreatmentofsoftrocktunne.lThistheorycanimprovetheeffectivenessofboltreinforcingsoftrocktunne.lThisconclusioninthepaperisusefulfordesignandconstructionoftunnelinhalf-hardandhalf-softrock.Keywords Hardrock,Softrock,Rocktunne,lCollapse,Tubeframe,Grouting,Surfacewithgroutingrein forcemen,tJiaoling

*收稿日期:2008-01-22;收到修改稿日期:2008-05-05.

,.j.