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1、侧向变形控制下的灰岩破坏规律及其峰后本构关系*王东1,2，王丁1,2，韩小刚1,2，周晓明1,2（1.四川大学水力学与山区河流开发保护国家重点实验室，四川成都610065；2.四川大学水利水电学院，四川成都610065)摘要：根据不同含水状态（干燥和饱和）和不同围压条件下的灰岩岩样的三轴压缩全程试验和峰后加卸载循环试验，分析干燥和饱水状态灰岩的变形破坏规律、围压对灰岩峰值强度和残余强度及破裂面角度的影响，研究灰岩峰前、峰后强度与变形之间关系。结果表明：不同围压水平引起不同破坏方式，泡水使灰岩的脆性增加；灰岩的残余强度与峰
2、值强度相比很小，且随峰后加卸载循环次数的增加继续衰减；该类灰岩在低围压下产生拉剪组合破坏，导致其破裂角度较Coulomb准则预测值偏大，在高围压下发生完全剪切破坏，破裂角度与Coulomb准则计算结果吻合；岩石轴向应力在峰值前是由其轴向应变决定的，峰后则由侧向变形控制，随侧向变形的增加逐渐衰减至残余强度。在此基础上建立了岩石本构模型，并推导了分段的岩石应力应变函数。利用该模型对岩石应力应变全过程进行计算，计算结果与试验结果吻合较好。关键词：岩石力学；围压；泡水；侧向变形；循环加载；峰后特性中图分类号：TU452文献标识码
3、：ALimestonefailurelawandpost-failureconstitutiverelationinthecontroloflateraldeformationWANGDong1,2,WANGDing1,2,HANXiaogang1,2,ZHOUXiaoming1,2(1.StateKeyLaboratoryofHydraulicsandMountainRiverEngineering,SichuanUniversity,Chengdu,Sichuan610065,China;2.CollegeofWat
4、erResourceandHydropower,SichuanUniversity,Chengdu,Sichuan610065,ChinaAbstract:Basedonthemechanicaltestsoflimestonewhichwereconductedunderdifferentmoistureconditions(fullysaturatedanddry)anddifferentconfiningpressures,andthecyclicloadingtestsofbrokenlimestone,anal
5、ysisofthelawofdeformationandfailure,theeffecttopeakandresidualstrengthandangleofrupturebroughtbyconfiningpressure,andtheresearchonthelawbetweenstrengthanddeformationofwholeprocesswerecarriedout.Thestudyresultsshowasfollows:differentconfiningpressureleadsdifferent
6、formoffailure,andporewaterwillstrengthenthebrittlenessoflimestone.Theresidualstrengthismuchsmallerthanthepeakstrength,anddecreasesasthecyclicloading.Theformoffailureaboutthisclassificationoflimestoneistension-shearingunderlowconfiningpressurewhichleadsahigherangl
7、eofrupture,andfullyshearingunderhighconfiningpressurewhichleadsaangleasCoulombcriterion.Theaxialstressiscausedbyaxialstrainbeforefailure,butcontrolledbylateralstrainafterfailureanddecreasestotheresidualstrengthasthelateralstrainincreasing.Basedonthat,limestonecon
8、stitutivemodelandstress-strainfunctionwerefounded,whichaccordwiththetestresults.Keywords:rockmechanics;confiningpressure;moisture;lateraldeformation;cyclicload
