近断层峡谷场地深水刚构桥地震响应参数敏感性研究

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关键词：近断层地震动；局部场地效应；深水刚构桥；敏感性 中图分类号： U441+.2 文献标志码：A DOI：10.16385/j.cnki.issn.1004-4523.202309066

Abstract：Alargenumberofhighpierrigidframebridgesinthecanyonareasarelocatedinnearfaultregins（hereinaftererred toasnearfault），andthseismicanalysesshouldcomprehensivelyconsiderthenearfaultefect，siteefect，andfluidstructurein teractionwhentheyarelocatedinthe waterenvironmentsuchasrivers，reservoirs，tc.Currntly，mostnearfultseismicrcords areusedasconsistentinputs，whichmayunderestimatetheseismicresponseof thebridges.Atthesametime，thediscusionon thecorelationbetweentheseismicsources，siteparameters，andseismicresponseofthebidgesisunexplored.Inthispaperthe stochasticfinitefaultmethodandtheboundaryelementmethodarecombinedtogeneratethemulti-dimensionalandmultipoint groundmotionsoftheoverlying water-layercanyonsites nearfaults，andtheanalysisofthe seismicresponseof thedep-water， large-span，highpierrigidframebridgeinthenearfultcanyonsiteisdeveloped.Thesensitvityoftheresponseofpiersandbear ingtotheseismicsourceandsiteparametersisinvestigated fromtheperspectiveofthewholephysicalprocessbetwentheseismic source and thestructure.Theresults indicatethatthebridgeresponseis mostsensitivetotherupture surface size.Onthewhole， theinfluenceofsourceparametersonthebridgeresponseismoresignificantthanthatofsiteparameters.Thesitefectleads tothe diferenceof the mean valuesofcurvature ductilityratiosof two main piers inlongitudinalandtransversedirections tobe 85% and 88% .There arediferences inthesensitivitiesofthe main piersand bearings toeach parameter.When thedipangleofthe fault is between 33∘～60∘ ，the seismic responseof the bridge shows atrendof increasing firstand then decreasing，and thecurvature ductility ratio of the main pier can differ by 35% . The water layer has an inhibitory effect on ground motions；however，the amplification effect of hydrodynamic pressures on the seismic response of the bridge is more prominent.

Keywords： near-fault ground motions；local site effect；deep-water rigid frame bridge；sensitivity

中国西部地区地形地貌复杂，随着高速公路/铁路的持续建设，出现了诸多穿越峡谷场地桥梁，其中刚构桥是常用、典型的结构形式，通常具有高墩、大跨的特点。（剩余19851字）