液化场地桩－土－桥梁结构地震相互作用振动台试验数值模拟方法研究.doc

《液化场地桩－土－桥梁结构地震相互作用振动台试验数值模拟方法研究.doc》由会员上传分享，免费在线阅读，更多相关内容在应用文档-天天文库。

1、液化场地桩－土－桥梁结构地震相互作用振动台试验数值模拟方法研究摘要：直接针对大型振动台模型试验，建立液化场地桩－土－桥梁结构地震相互作用数值模拟的二维分析模型和计算方法。根据桩基平面应变假定，将空间桩体转换成平面板桩，并考虑桩的尺寸效应；基于桩截面节点位移协调条件和平衡力系等效原理，建立四结点梁单元刚度矩阵且对Timoshenko梁杆单元刚度矩阵进行增广修正，以考虑桩的横向尺寸影响桩周土位移场分布的尺寸效应。根据有效应力原理进行土动反应分析，采用满足Masing准则的修正双曲线模型描述土动力变形的本构关系，同时考虑因孔压上升造成土体软化而对土动力性

2、能的影响，由迭代法处理土的动力非线性。采用并联弹簧－阻尼器模拟计算域人工边界，以考虑边界波的反射作用对体系动力反应的干扰和土粘滞阻尼的影响。采用逐步积分法计算体系的地震反应。通过与试验结果的对比分析，评估数值模拟的建模途径和计算方法的可靠性。关键词：大型振动台模型试验；数值模拟；桩－土－桥梁结构地震相互作用；液化场地。中图分类号：U442.55文献标识码：ANumericalSimulationMethodofShakingTableTestonEarthquakeIntractionofPile-Soil-BridgeStructureinLiq

3、uefactionSiteAbstract:Directlyaimingatlarge-scaleshakingtablemodeltest,thepaperwillestablishtwo-dimensionanalysismodelandnumerationmethodonnumericalsimulationmethodofearthquakeinteractionofpile-soil-bridgestructureinliquefactionsite.Basedontheassumptionofplanestrainofpilefound

4、ationandconsideringscaleeffectofpile,specialpilebodiesaretransformedintoplanesheetpile.Accordingtothedisplacementharmonyconditionofpilesectionnodeandtheequivalentprincipleofforcesystem,theanalysismodelwillsetupfourcrunodeselementstiffnessmatrixofbeamcellandamendTimoshenkobeam-

5、polestiffnessmatrixincreasinglyinordertoconsiderthedisplacementfielddistributionofsoilnearbythepileasaresultofdimensioneffectofpilelandscapeorientation.Dependonsoildynamicresponsebyeffectivestresstheory,theamendatoryhyperbolicmodelwhichaccordswithMasingruleisadoptedtodescribec

6、onstitutiverelationofsoildynamicdeformationandtheeffectforsoilinteneratingcausedbyriseofporewaterpressureonsoildynamicperformanceistakenintoaccountthroughiterationmethodtodealwiththeproblemofsoilnonlinearmomentum.Parallelspring-counterbuffermodelisusedtosimulateartificialbound

7、aryinthecomputationregiontoconsidertheeffectwhichderivedfromreflectionofboundarywaveontheinterferenceofsystemdynamicreactionandviscousdampingofsoilandthesuccessiveintegralmethodisintroducedintoseismicresponseofthecalculationsystem.Comparedwiththeresultfromthetest,thecalculatio

8、nmethodandthepathofmodelbuildingfornumericalvaluesimulationar