岩石结构蠕变稳定性理论的研究

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1、辽宁工程技术大学硕士学位论文岩石结构的蠕变稳定性理论研究姓名：何峰申请学位级别：硕士专业：工程力学指导教师：王来贵20050201摘要岩石的结构是极其复杂的非连续和非均质体其力学属性具有非线性各向异性及随时间变化的流变特性岩石工程结构失稳前特征即应力状态保持不变且是突然破坏释放能量即蠕变失稳所以开展岩石蠕变破坏机理的研究对岩石工程的长期稳定性具有重要的理论意义和实际价值本文主要从岩石全程应力应变特征和蠕变曲线出发进行研究建立蠕变失稳模型把模型中的两个参数看作是随岩石的变形而变化得出失稳判据和改进的蠕变方程进而解释了岩石蠕变的第三阶段失稳现象同时从不同角度推导出模型的各种

2、解析解这些方程表明岩石的本构关系变形模量与加载条件和历史有关验证了该模型是能描述岩石的衰减蠕变稳定蠕变与加速蠕变三种情况的比较完善的流变模型结合蠕变模型和流变力学的一般解法推导出了采空区悬顶板梁临界载荷及应力的粘弹塑性解析解并对其稳定性进行了分析推导出圆形洞室周围岩石任意点的位移随时间增长而变化的方程并得出了粘塑性区半径建立了含软弱夹层的层状边坡板梁失稳模型改进了欧拉公式具有时间效应提出了一种边坡失稳的分析方法关键词流变力学蠕变模型失稳时间效应ABSTRACTThestructureofrockisextremelycomplicateddiscontinuousand

3、heterogeneousbody,itsmechanicspropertyhasnon-linear,anisotropismandrheologycharacteristic,whichchangedovertime.Thecharacteristicstressstateofrockstructureiskeepingconstantbeforeitslosingsteady,andsuddenlydestroyedwithreleasingenergy,namelycreepislosingsteady.Soitisimportanttheorymeaninga

4、ndrealityvaluetolong-termstabilityofrockengineeringtolaunchresearchofrockcreepingdestroyingmechanism.Thetextproceedsfromthewholestress-straincharacteristicandcreepcurveofrock,setupcreeplosingsteadymodel,regardtwoparametersofmodelaschangingwithdeformationofrock,drawlosingsteadycriterionan

5、dmodifiedcreepequation,andthenhasexplainedlosingsteadyphenomenonatthethirdstageofrockcreepAtthesametimewederivedoutanalyticalsolutionofthecreepmodelfromdifferentangles,andindicateconstitutiveofrockanddeformationofmoduluswhichrelatetotheconditionandhistoryofloading,andprovethatitisaperfec

6、trheologymodelwhichcandescribedecaycreep,stabilitycreepandacceleratecreepofrock.Thetextcombinescreepmodelandgeneralsolutionofrheologymechanics,derivingoutvisco-elasto-plasticanalyticsolutionofcriticalloadandstressofoperationgoafhangingbeam,andanalyzeditsstability;Derivingoutdisplacemento

7、fwallrockwhichincreaseswithtimechanges,andhasdrawnradiusofplasticitydistrict;Setuplosingsteadybeammodelofslopecontainingweakintermediatelayer,modifiedEulerformulahasatimeeffect,puttingforwardlosingsteadyanalyticalmethodoftheslope.Keywords:rheologymechanics;creepmodel;losi