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ID:52220557
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时间:2020-03-25
《深部节理岩体分区破裂化机制数值研究.pdf》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、第30卷第1期2013年1月公路交通科技JournalofHighwayandTransportationResearchandDevelopmentV01.30No.1Jan.2013doi:10.3969/j.issn.1002—0268.2013.01.017深部节理岩体分区破裂化机制数值研究苏永华,郑璇(湖南大学土木工程学院,湖南长沙410082)摘要:基于深部地下工程围岩反复承受地质力作用和开挖扰动,其完整性和力学性能弱化的现实,认为其应力一应变关系服从峰后软化的遍布节理模型,然后考虑节理、原岩应力以及影响岩体性质的变形参数和强度参数等因素,设计模拟方案,
2、利用FLAC30数值软件,再现了围岩分区破裂化过程。模拟结果表明:节理的存在和分布对分区破裂化现象的形态和规模存在很大影响。岩体强度与原始应力场的相对关系是引发围岩分区破裂化的关键。当初始地应力超出岩体单轴抗压强度时,围岩将出现分区破裂现象,初始力相对于岩体强度、泊松比的增大与分区破裂的数目、破裂区延伸长度、破裂区范围等成近似的正比,而内摩擦角则呈现相反趋势。这一结果部分揭示了分区破裂发生的力学机制,为深部围岩支护设计理论的建立提供了有益参考。关键词:隧道工程;深部节理岩体;数值模拟;分区破裂化现象;应力应变软化;变形参数;强度参数中图分类号:U452.1+2文献标
3、识码:A文章编号:1002—0268(2013)01—0094一08NumericalStudyonMechanismofZonalDisintegrationinDeepRockMasswithJointssuYonghua,ZHENGXuan(CollegeofCivilEngineering,HunanUniversity,ChangshaHunan410082,China)Abstract:Basedontherealitythatsurroundingrocksofdeepundergroundengineeringrepeatedlybeargeolog
4、icalforceandexcavationdisturbance,theinte‘grityandmechanicalpropertieswereweakened,itisthoughtthatthestress—strainrelationsubmitstothepost—peaksofteningjointmodel,andthenconsideringotherparameterslikejoints,originalrockstress,strengthanddeformationparametersthataffectingrockmasspropert
5、y,thesimulationschemeisdesigned,andFLAC如numericalsoftwareisusedtoreproducetheprocessofzonaldisintegration.Thesimulationresultshowsthat(1)theexistenceanddistributionofjointshaveagreatimpactontheformandscaleofzonaldisintegrationinjointedrock,therelativerelationbetweenrockmassstrengthando
6、riginalstressfieldisthekeytozonaldisintegration;(2)whentheinitialgeostressexceedstherockuniaxialcompressivestrength,surroundingrockwillbefractured;(3)initialgeostressisapproximatelyproportionaltorockmassstrength,increaseofPoisson’Sratio,numberofzonaldisintegrationandextensionlengthofru
7、pturezone,etc.,whilefrictionanglerevealscontrarytrend.Thisresultpartlyrevealedthemechanicalmechanismofzonaldisintegration,providedabeneficialreferenceforthefoundingofdeepsurroundingrocksupportingdesigntheory.Keywords:tunnelengineering;deepjointrockmass;numericalsimulation;zonaldisint
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