哈尔滨工业大学硕士学位论文抗拔桩的承载性能姓名：张磊申请学位级别：硕士专业：工程力学指导教师：王幼青20050101哈尔滨工业大学工学硕士学位论文摘要各种高层高耸及承受浮托力的建筑物已广泛地采用抗拔桩作为其基础形式，因而抗拔桩在荷载作用下的工作性状己成为岩土工程界日益关注的热点课题。本文利用有限元方法及R．Mindlin对于土体内部作用荷载使土体产生位移的方程式建立了一种新的单桩一土体体系的力学模型，该模型一方面考虑了桩体泊松比效应的影响，也就是考虑了桩的竖向位移与径向位移的协调性；另一方面考虑了土体的非线性变形的特点，并根据所建立的模型编制了相应的Fortran源程序。本模型不仅可以对承受上拔荷载的单桩一土体体系进行分析，还可以对承受下压荷载的单桩一土体体系进行分析，同时还可以将前两者进行对比分析。采用本文所建立的模型对三个抗拔桩和两个抗压桩的工程实例进行计算分析，结果表明本文所建立的模型对抗拔桩与抗压桩计算均较适合。此外还研究了影响抗拔桩与抗压桩荷载一位移曲线的几种因素，包括：桩直径；桩长；桩的弹性模量；土的弹性模量；初始剪切刚度：极限侧阻；土的泊松比等等。此外，为了研究抗拔桩较抗压桩桩侧摩阻力的发挥，本文采用模拟分析的方法研究了桩体泊松比效应对抗拔桩侧摩阻力的分布及发挥的影响，并分别改变桩长及桩直径来讨论长径比对桩侧摩阻力发挥的影响。本文的研究讨论取得了一定的成果，可为实际工程设计提供参考。关键词抗拔桩；泊松比效应；侧摩阻力；长径比堕玺鎏三些銮兰三兰譬：：：=：墨鲨兰AbstractUpliftpilesasasortoffootingshasawiderangeofapplicationsforavarietyofhighrisebuildingsandbearingbuoyancybuildings，SOthebehaviorofupliftpilesundertheverticalloadhasgraduallyincreasedinthegeotechnicalengineering．ThispaperhasutilizedthefiniteelementmethodandelasticitytheorysolutionwhichR．Mindlinintroducedtheequationsforthedisplacementswithinasoilmasscausedbyloadingwithinthemass，andhasestablishedanewsortofmechanicsmodelofsinglepile_soilmasssystem．Ononehand．thismodelhasconcernedtheaffectionofthePoisson’Srationeffect．matisbothverticalandradialdisplacementcompatibility．Ontheotherhand，thismodelhasconcernednonlineardeformationofthesoilmass．ThispaperhasprogrammedFortransourceprogramintermsofthismodelthatthispaperhasestablished．Themodelisabletoanalyzesinglepile-soilmasssystemundertheupliftload，andunderthedownwardload，andcontrastivelyanalyzesinglepile—soilmasssystemunderboththeupliftloadandthedownwardload．Byusingthemodelthatthispaperhasestablishedtocalculateandanalyzethethreerepresentationalexamplesofpilesunderupliftloadsandthetworepresentationalexamplesofpilesunderdownwardloads，theanalysisresultshasshownthatthecalculatedresultscorrespondwithmeasuredresultsofthepilesunderbothupliftloadsanddownwardloads．Furthermore，thispaperhasresearchedtheserieseffectingfactorssubjectedtoload—displacementcurvesofpilesunderbothupliftloadsanddownwardloads，includingthat：thediameterofpiles；thelengthofpiles；themodulusofpiles；themodulusofsoilmass；theinitialshearstiffness；theultimatesideresistanceofpiles；thePoisson’SratioofsoilmassandSOon．Inordertoresearchtheexertionofthesideresistancesofpilesunderbothupliftloadsanddownwardloads，thispaperresearchesthathowthePoisson’Sratioeffectaffectsthedistributionandtheexertionofthesideresistanceofupliftpiles，andhowtheslendernessratioaffectstheexertionofthesideresistancebychangingthelengthofpilesandthediameterofpilesrespectively．Theresearchofthispaperhasobtainedaseriesofefforts，anditcallprovide-II-哈尔滨工业大学工学硕士学位论文referencesfortherealisticengineeringdesignofupliftpiles．...
