文档名：不同因素导致的差异沉降对盾构隧道受力特性影响研究
摘要：盾构隧道在下卧地层软硬突变、局部堆载等因素影响下易产生不均匀沉降,可能诱发管片环间错台、螺栓断裂和接缝渗水等病害,危及隧道安全.然而,现有试验研究在隧道模型上多将纵向接头简化处理,难以反映盾构隧道纵向受力变形特性,对于隧道下卧软硬突变地层等工况的模拟也较为缺乏.为此,提出一种可同时模拟抗拉、抗弯刚度的"弹簧+螺栓型"接头,并以此接头制作可满足纵向力学性能相似的隧道模型,对盾构隧道进行下卧软硬突变、局部堆载等工况下的模型试验,进一步探明不同因素导致的差异沉降对盾构隧道的影响机理,并采用数值模拟验证了试验的可行性.研究结果表明:1)较单一地层而言,隧道下卧软硬突变时纵向沉降曲线呈现明显的非线性,其隧道沉降及差异沉降最值显著增大,软土侧隧道沉降较硬土侧更为显著,最大沉降、沉降差均出现在突变区软土侧衬砌处;2)下卧地层突变导致隧道横向收敛变形在纵向上分布不均,使软土侧衬砌收敛变形减小,硬土侧衬砌收敛变形显著增大;3)局部堆载对管片弯矩分布影响较小,对弯矩最值影响较大;4)下卧软土区隧道结构内力分布明显变异,隧道衬砌正弯矩区域显著增大,负弯矩区域略有减小,且弯矩最值提升显著.因此针对软硬突变地层,必要时在硬土侧隧道可采用粘钢法等方法提升衬砌横向刚度,以控制其收敛变形;软土侧隧道建议对管片进行螺栓复紧,并加强接缝防水,以减小下卧地层弱化对隧道结构产生的不利影响.
Abstract：Shieldtunnelsaresusceptibletounevensettlementduetofactorssuchasabrupttransitionsbetweensoftandhardunderlyingstrataandlocalizedoverburdenloading,whichcanleadtodistressissuesincludingmisalignmentbetweentunnelsegments,boltfractures,andwaterinfiltrationthroughjoints,consequentlyimperilingtunnelsafety.However,existingexperimentalstudiesoftenoversimplifylongitudinaljointsintunnelmodels,makingitdifficulttocapturethelongitudinaldeformationcharacteristicsofshieldtunnels.Additionally,thereisalackofsimulationinvolvingconditionssuchasabruptvariationsbetweensoftandhardunderlyingstratawithintunnels.Tothisend,anovel'spring+bolt'jointthatcouldsimultaneouslysimulatetensileandflexuralstiffnesswasproposed,andthisjointwasutilizedtofabricatetunnelmodelsthatmeetthesimilarlongitudinalmechanicalproperties.Themodeltestoftheshieldtunnelundertheconditionsofabruptvariationsbetweensoftandhardunderlyingstrataandlocalstackingwasthencarriedouttofurtherexploretheinfluencemechanismofdifferentialsettlementcausedbydifferentfactorsontheshieldtunnel,andthefeasibilityofthetestwasverifiedthroughnumericalsimulations.Theresultsindicatethat:(1)comparedwiththeuniformstratum,thelongitudinalsettlementcurveofthetunnelexhibitssignificantnonlinearitywhenencounteringabrupttransitionsbetweensoftandhardunderlyingstrata.Bothtunnelsettlementanddifferentialsettlementexperiencenotableincrements,withmorepronouncedeffectsobservedonthesoftsoilsidecomparedtothehardsoilside.Maximumsettlementandsettlementdifferentialareconcentratedattheinterfaceofthesoftsoilliningwithintheabrupttransitionzone.(2)Theabrupttransitionofunderlyingstrataleadstoanunevenlongitudinaldistributionoflateralconvergencedeformationwithinthetunnel,whichreducestheconvergencedeformationoftheliningonthesoftsoilsideandsignificantlyincreasestheconvergencedeformationoftheliningonthehardsoilside.(3)Localizedoverburdenloadinghasaminorimpactonthebendingmomentdistributionofthesegmentbuthasagreatinfluenceonthemaximumbendingmoment.(4)Theinternalforcedistributionofthetunnelstructurewithintheunderlyingsoftsoilareaisnoticeablyvariable.Thepositivebendingmomentareaofthetunnelliningincreasessignificantly,whilethenegativebendingmomentareadecreasesslightly,andthereisamarkedelevationinthemaximumbendingmomentvalue.Therefore,inviewofthesoft-to-hardabruptstrata,itisprudenttocontemplateenhancingthelateralstiffnessoftunnelliningsonthesidewithhardsoilthroughmethodssuchastheapplicationofbondedsteel,aimedatmanagingtheirconvergencedeformation.Conversely,inviewoftunnelssituatedonthesidewithsoftsoil,itisrecommendedtoimplementboltretighteningoftunnelsegmentsandenhancejointwaterproofingtomitigatetheadverseeffectsstemmingfromtheweakeningoftheunderlyingstrataonthetunnelstructure.
作者：石钰锋 胡梦豪 周宇航 黄大维 黄展军 陈焕然 Author：SHIYufeng HUMenghao ZHOUYuhang HUANGDawei HUANGZhanjun CHENHuanran
作者单位：华东交通大学土木建筑学院,江西南昌330013;华东交通大学江西建筑设计院有限公司,江西南昌330013华东交通大学土木建筑学院,江西南昌330013南昌轨道交通集团有限公司,江西南昌330199
刊名：铁道科学与工程学报 ISTICPKU
Journal：JournalofRailwayScienceandEngineering
年，卷(期)：2024, 21(4)
分类号：U45
关键词：盾构隧道 模型试验 等效刚度 差异沉降 纵向接头
Keywords：shieldtunnels modeltests equivalentstiffness differentialsettlement longitudinaljoints
机标分类号：U459.1TU473.1TU312.1
在线出版日期：2024年5月17日
基金项目：国家自然科学基金不同因素导致的差异沉降对盾构隧道受力特性影响研究[
期刊论文] 铁道科学与工程学报--2024, 21(4)石钰锋 胡梦豪 周宇航 黄大维 黄展军 陈焕然盾构隧道在下卧地层软硬突变、局部堆载等因素影响下易产生不均匀沉降,可能诱发管片环间错台、螺栓断裂和接缝渗水等病害,危及隧道安全.然而,现有试验研究在隧道模型上多将纵向接头简化处理,难以反映盾构隧道纵向受力变形...参考文献和引证文献
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不同因素导致的差异沉降对盾构隧道受力特性影响研究 Study of the effect of differential settlement due to different factors on the force characteristics of shield tunnels
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