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1、粘结刚度对预应力锚杆支护效用的数值分析收稿日期:基金项目:国家自然科学基金资助项目(U1261211,51434006)作者简介:王晓卿(1988-),男,河北高邑人,在读博士。Tel:13051596237,E-mail:84028372@163.com王晓卿1,2,康红普2,赵科2,刘跃东2(1中国矿业大学(北京)资源与安全工程学院,北京100083;2天地科技股份有限公司开采设计事业部,北京100013)摘要:层状顶板是煤巷的典型赋存特征。为明确粘结刚度对层状顶板锚杆支护效用的影响,本文首先介绍了粘结刚度的概念及在
2、FLAC3D中的实现方式,然后利用FLAC3D的interface单元建立了层状顶板巷道模型,综合pile和liner结构单元构建了仿真锚杆模型,并实现了预紧力施加功能,在原岩应力条件下分析了不同粘结刚度对层状顶板的支护效用。研究结果表明:粘结刚度控制锚杆的增阻特性,随粘结刚度增大,锚杆的增阻特性由缓转急;锚杆支护可显著控制层状顶板离层,粘结刚度越大,控制效果越好;锚杆支护应力场可显著改善巷道围岩的应力状态,减小乃至消除拉应力分布,粘结刚度越大改善效果越明显;锚杆杆体受层理层间滑动影响会发生弯曲变形,但随粘结刚度增大,变
3、形程度得到缓解。鉴于粘结刚度的重要性,提出了提高锚杆粘结刚度的技术途径:优化杆体外表形状、改善围岩接触条件、增强锚固剂粘结性能及提高锚固剂安装质量。关键词:锚杆;粘结刚度;层状顶板;离层;数值模拟中图分类号:TD353文献标识码:ANumericalanalysisofbondingstiffnessforsupporteffectivenessofprestressedboltsWANGXiaoqing1,2,KANGHongpu2,ZHAOKe2,LIUYuedong2(1FacultyofResourcesandS
4、afetyEngineering,ChinaUniversityofMiningandTechnology(Beijing),Beijing100083;2CoalMiningandDesigningDepartment,TiandiScienceandTechnologyCo.,Ltd.,Beijing100013)Abstract:Stratifiedroofistypicaloccurrencecharacteristicforcoalroadway.Toclarifyimpactsofbondingstiffne
5、ssonboltssupporteffectivenessforstratifiedroof,conceptofbondingstiffnessanditsrealizationwayinsoftwareFLAC3Dwerefirstlyintroduced,thenroadwaymodelwithstratifiedroofwasestablishedusinginterfaceelementsofFLAC3D,andemulationalboltsmodelwasconstructedbymeansofintegra
6、tingpilestructuralelementswithlinerstructuralelements,whosepretensionimposingmethodwasalsoputforward.Basedonthese,supporteffectivenessofdifferentbondingstiffnessforstratifiedroofwereanalyzedsimulativelyunderconditionofin-situstress.Theresultsshowthat:(a)Thebondin
7、gstiffnessdeterminesresistance-increasingcharacteristicsofbolts,whichvaryfromslownesstorapidnesswiththeincreaseofbondingstiffness.(b)Boltssupporthasdefinitecontroleffectivenessforseparationofstratifiedroof.Thegreaterthebondingstiffness,thebetterthecontroleffectiv
8、eness.(c)Supportingstressfieldofboltscanimprovestressstatedistinctly,diminishingeveneliminatingthedistributionoftensionstress.Theimprovingeffectwouldgetbetteri