简介:摘要:当前,我国高速铁路建设规模日益提高,在规划高速铁路中,有相当一部分比例属于软弱围岩隧道。当隧道处于软弱破碎带时,围岩破碎、稳定性差、围岩偏压等现象普遍存在,支护受力情况复杂,围岩大变形、塌方等工程事故极易发生,给隧道建设带来极大困难。围岩变形是评价隧道围岩稳定性的重要指标,也是隧道设计的基本准则之一。隧道开挖后,围岩变形稳定性大致经历3个阶段:弹性变形阶段、弹性变形和塑性变形共存阶段、以流变为主,流变和塑性变形共存,同时围岩发生损伤、断裂、挤出及膨胀耦合作用阶段。本文主要对高速铁路软弱围岩隧道挤压变形控制技术进行论述,希望通过本文的分析研究,给行业内人士以借鉴和启发。
简介:AstudyonhotextrusionofTi-6Al-4Vusingsimulationsandexperiments;Dampingcharacterizationofaluminiumcontaininginterconnectedwirereinforcementusinganovelfiequencydomainbasedmethod;DevelopmentofAl-Si-MgAlloysreinforcedwithBoronCarbideParticles;DevelopmentofAl-Si-MgAlloysreinforcedwithBoronCarbideParticles;
简介:Finiteelementinvestigationsupontheinfluenceofpocketdiedesignsonmetalflowinaluminiumextrusion-PartI.effectofpocketangleandvolumeonmetalflow,InfluenceoftheGeometryoftheExtrusionDieontheMeltStrengthofPolymers,Innovativemanufacturingtechniqueforglassmatrixcomposites:extrusionofrecycled.TVsetscreenglassreinforcedwithAl{sub}O{sub}3platelets,Measurementofdeformationofextrusiondieinhotextrusionofaluminum-deformationofextrusiondieinaluminumhotextrusionⅡ.
简介:Asurveyofmanifolddesignsforflatdieextrusion;CermetDiesforHotExtrusionofHardAluminium;Clustercomputinginnumericalsimulationofextrusionflow;Computeraideddesignandmanufactureofstreamlinedextrusiondies;Depositionofhardfilmsonhot-workingsteeldiesforaluminium;DevelopmentofaremotequickCAEsystemonsculpturedmetalextrusiondiesurface;
简介:AStudyofRadialGearExtrusion,Atheoreticalandexperimentalstudyoffrictioninmetalformingbytheuseoftheforwardextrusionprocess,Deepdrawingandimpactextrusionofmagnesiumalloysatroomtemperature,Effectsofdiegeometryandextrusionspeedonthecoldextrusionofaluminiumandleadalloys,FeatureextractionfromSTEP(ISO10303)CADdrawingfilesformetalformingprocessselectioninanintegrateddesignsystem,Formingfeaturerepresentationandprocessselectionincoldextrusion.
简介:EffectsofaddingLa-richmischmetalonthemicrostructureandmechanicalpropertiesofhotextrudedMg-8Alalloys;Effectsofextrusionconditionsonhotextrudingcharacteristicsofmagnesiumalloy;Expertevaluationofhydraulicpressreliability;ExtrudabilityimprovementandenergyconsumptionestimationinAIextrusionprocessofa7003alloy;Fabricationofcompositepipesbymulti-billetextrusiontechnique