高边坡监测与稳定性

中图分类号：西南交通大学研究生学位论文碎裂岩质高边坡现场监测与稳定性评价年级2004级姓名闫振申请学位级别工学硕士专业道路与铁道工程指导教师陆阳教授二○○七年五月ClassifiedIndex:U.D.CSouthwestJiaotongUniversityMasterDegreeThesisFIELDMONITORINGANDSTABILITYANALYSISFORREINFORCINGROCKHIGH-SLOPEOFRODEBASEClass:CivilEngineering2004Candidate:YanzhenAcademicDegreeAppliedfor:MasterofEngineeringMajor:RoadandRailwayEngineeringSupervisor:Prof.LuYangMay,2007西南交通大学硕士研究生学位论文第I页摘要路堑高边坡的施工，是一个破坏山体原有力学平衡而又用支护工程重建力学平衡的过程。路堑边坡的开挖必然导致坡体内部应力场的重分布，产生变形；对此必须采取适当的工程措施，确保边坡的变形收敛、整体稳定。但是，鉴于边坡地质情况的复杂性、施工过程影响因素的不确定性以及对路堑边坡的地质勘探水准的限制，对边坡的变形稳定事先准确预测还存在很大困难。因此，通过重要边坡的现场监测，可以为指导设计施工提供重要的基础数据，确保路堑高边坡安全。另一方面，通过现场监测可以了解边坡的状态改变及发展趋势，以检验支护工程效果，为类似工程的设计提供参考借鉴。论文结合四川省交通厅计划科研项目“深挖岩质边坡稳定性分析及支挡防护方法研究”(项目编号：99003)，以西攀高速公路K132＋472～＋565高边坡为依托工点，开展岩质边坡现场监测及施工期稳定性评价。为以后同类边坡工程的稳定性评价和处理，提供了理论研究和实际参考价值。本论文主要研究工作如下:(1)在收集有关工程地质和水文地质资料的基础上，根据实际工程地质条件对边坡的潜在破坏模式进行了初步分析。并对该边坡的岩石进行常规及三轴试验，结合野外工程岩体结构特点及相关经验性资料，以获得边坡稳定性评价的岩石力学参数。(2)针对碎裂岩质边坡施工期的特点，结合K132高边坡监测方案的设计与实施，对碎裂岩质边坡动态监测过程进行了探讨。认为，边坡动态监测综合考虑了边坡施工过程中多种因素的相互影响，能较全面地把握边坡的内部变形及坡体应力变化情况，为边坡稳定性判断提供更多更可靠的信息。监测应用表明:该设计方法全面、可靠，较好地满足了高边坡的动态监测要求。(3)讨论了安全监测在边坡工程中的重要性，对K132高边坡所取得的监测资料进行了详细的分析，分析了边坡施工期的变形特征，并与所计算的稳定性和变形量等成果进行了对比。在对测斜数据的处理过程中，为了提高边坡稳定性评价的准确性，将小波分析应用在边坡水平位移监测曲线的降噪中，选用小波阈值法对西攀高速公路K132高边坡监测数据进行降噪，结果证明有效。西南交通大学硕士研究生学位论文第II页(4)为配合K132高边坡的信息化施工，确立了分阶段实施陡坡路基挖方工程边坡原位支护结构的应力和变形状态监测方案。监测结果表明，施工第一阶段，认为边坡岩体整体较稳定，但断层及断层破碎带岩体极为破碎，浅层稳定性差，适当放缓了边坡开挖坡比，并将第四、五级边坡锚杆长度减短。第二阶段，通过开挖所揭示的岩层产状及钻孔取样获取的信息，综合深部位移监测数据分析，确定本阶段两级边坡防护设计按原方案正常施工。第三阶段，综合监测数据及一级坡面开挖揭示的工程地质条件，将一级边坡原设计预应力锚索桩改为框架锚索。达到了保证工程安全、降低施工难度、保证工程措施经济合理的目的。关键词：岩质边坡；现场监测；小波降噪；信息化施工；稳定性评价西南交通大学硕士研究生学位论文第III页AbstractExecutionforhigh-slopeofrodecuttingisaprocesswhichinheremechanicalequilibriumisbrokenandnewequilibriumisreconstructedbysupporting.Forcefieldwillredistributionanddistortionwillaccrueifexcavationbeadopted.Someengineeringmeasuresmustbeadoptedinordertoinsureslopestability.Itisdifficulttoforecastslopedistortionaccuratelybecausecomplexityofgeology,uncertaintyofaffectingfactorofconstructionworkandlimitofgeologicalexplorationcapability.Sofieldmonitoringisveryimportant.Ononehand,somebasicdatacanbeofferedwhichcanguidedesignandexecution.OntheotherhandwecankNowstateofhighslopeandtrendofdistortion.Thecomplexityoftheslopemakesitdifficulttopredictthebehavioroftheslope.Inordertosolvethisproblem,amethodthattheslopisdesignedassistantbyinformationandmonitorisbeeninducted.TheexcavationstabilityandreinforcementeffectsoftheslopeatK132ofXichang-Panzhihuahighwayweresystematicallyandprofoundlystudied.Themainstudyincludesfourpartsasbelow:(1)Basedonthesitesurvey,topographicalconditionandgeologicinformationachievedbeforeexcavationoftherockhigh-slope.Toanalyzethefailuremodelofplantbackslopebycollectingtherelevantengineeringandhydrologicgeologycondition;Continuitymodelofengineeringrockmassesisbuilt.Theschematizationmethodofthecontinuityofengineeringrockmassisreported.Atmountainareasthenaturalslopefailureoftenoccurafterconstructionofhighways.Conventionaltestsandclaytestsfromasampleillustrationwereconductedwhichcombinethefieldfeaturesofengineeringrockandsomeexperimentaldatainordertoobtainthecomputationparametersforslopestabilityanalysis.Thecalculationresultsareprovidedfornonlinearfiniteelements(FEM)foranalysisofexcavatedslope.Theresultsshowedthatitiseffectiveandreasonablewaytodetermineparametersofengineeringrockmasses.(2)InallusiontofeatureofconstructionperiodforK132cataclasiteslope,somediscusshavemadeondynamicmonitoringprocess.Itisbelievedthatbydynamicmonitoringthatdiversifiedfactorsbeconsideredandmorecredibilityinformationbeoffered.Wecangraspdistortionandstressofsloperoundly.Theresultshowsthatthedesignofmonitoriscomprehensiveandcredibility.(3)Significanceoffieldmonitoronslopehasbeendiscussed.Detailedanalysisonallinformationofmonitoringhavebeenmadeinordertopredictthebehavioroftheslopeandestimatetheexcavationstability.Undulationindisplacementmonitoringcurveofslopebothreflectabruptchangeswhichnatureandmanpowerbringaboutandreflectinfluenceofambientnoise.It’simportanttoeliminatingthenoiseofslope’sdisplacementmonitoringforimproveveracityofslopestabilityevaluation.Thereareabroadapplicationsineliminatingnoiseofsignal.Inthispaper,waveletanalysisisusedtostudythemethodsforeliminatingthenoiseof西南交通大学硕士研究生学位论文第IV页slope’sdisplacementmonitoringdates.ThenonlinearwaveletthresholdisusedforeliminatingnoiseofdisplacementmonitoringdatesinXi-PanhighwayK132slope.Theresultsshowthismethodiseffective.(4)Constructwithmonitoringdataisascientificmethod.Gradingexecuting,gradingchoosingallkindsofinformationandgradingperfectdesignswereadoptedinsupportingworks.Withreferencetomonitoringdata,adjustsupportingengineeringmeasurestimely.Todiscussthearrangementprincipleofsafetymonitoringinstrumentsinengineeringslopes,analyzethedeformationdataacquiredbythemonitoringinstruments,studythestabilityofslopeduringdiggingandtheactualdeformationcharactersofslopeandmakeacontrastwiththeresultsacquiredbymonitoringdata.KeyWords:rockslope;fieldmonitoring;noisereductionbywavelet;constructingwithmonitoringdata;stabilityevalua