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ID:27900220
大小:3.04 MB
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时间:2018-12-06
《深埋隧洞岩体开挖瞬态卸荷机制及等效数值模拟.doc》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、深埋隧洞岩体开挖瞬态卸荷机制及等效数值模拟卢文波1,2,杨建华1,2,陈明1,2,周创兵1,2(1.武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072;2.武汉大学水工岩石力学教育部重点实验室,湖北武汉430072)摘要:岩体爆破开挖过程中,开挖荷载瞬态卸荷伴随着爆破破岩的裂纹扩展、爆生气体逸出以及新自由面形成等过程而发生。针对深埋隧洞全断面钻爆开挖,确定分段微差爆破对应的分步开挖荷载,分析爆炸荷载耦合作用下的开挖荷载瞬态卸荷方式与持续时间,实现开挖荷载瞬态卸荷的荷载边界条件的数学描述。考虑到炮孔近区岩体因爆破
2、破碎引起的介质连续性的改变及其所经历的复杂应力状态,根据炮孔周围岩体爆破破坏的空间分布特征,基于等效弹性作用边界的概念,提出群孔起爆条件下爆炸荷载与开挖荷载瞬态卸荷耦合作用的等效数值模拟方法。现场实测振动数据验证了计算结果的正确性。关键词:岩石力学;深埋隧洞;开挖;爆破;瞬态卸荷;等效模拟中图分类号:TU45文献标识码:A文章编号:1000–6915(2011)06–1089–08MECHANISMANDEQUIVALENTNUMERICALSIMULATIONOFTRANSIENTRELEASEOFEXCAVATIONLO
3、ADFORDEEPTUNNELLUWenbo1,2,YANGJianhua1,2,CHENMing1,2,ZHOUChuangbing1,2(1.StateKeyLaboratoryofWaterResourcesandHydropowerEngineeringScience,WuhanUniversity,Wuhan,Hubei430072,China;2.KeyLaboratoryofRockMechanicsinHydraulicStructuralEngineeringofMinistryofEducation,Wu
4、hanUniversity,Wuhan,Hubei430072,China)Abstract:Thetransientreleaseofexcavationloadisaccompaniedbythedevelopmentofcracks,theoutburstofdetonationgasesandtheformationofnewfreesurfaceduringtherockfragmentationbyblasting.Forthecaseoffullfaceexcavationofdeeptunnel,divisi
5、onalexcavationloadscorrespondingtomilli-seconddelayblastingaredecidedfirst;andamathematicaldescriptionoftheloadboundaryconditionduringthereleaseofexcavationloadsispresentedthroughanalyzingthemodeanddurationoftransientreleaseofexcavationloads.Consideringthecomplexst
6、ressstaleandchangeofcontinuitystateofrockmassaroundblastholecausedbyrockfragmentationbyblasting,anequivalentnumericalmethodisproposedtosimulatethecouplingofblastingloadandexcavationloadformulti-holeblastinginaccordancewiththespatialdistributioncharacteristicsofblas
7、t-induceddamagezoneandtheequivalentelasticboundary.Comparisonbetweensimulationresultsandmonitoringdataindicatesthattheproposedequivalentsimulationmethodisapplicabletopredictingthedynamicresponseofsurroundingrockduringtheblastingexcavationofdeeptunnel.Keywords:rockm
8、echanics;deeptunnel;excavation;blasting;transientunloading;equivalentsimulation1引言我国在建和即将兴建的一批大型、特大型水电工程都处在西南、西北地区的崇山峻岭之中,埋深大,高地应力问题突出。例如锦屏二级水电站4
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