近断层地震动作用下斜交梁桥碰撞效应研究

近断层地震动作用下斜交梁桥碰撞效应研究近断层地震动作用下斜交梁桥碰撞效应研究

摘要

本文针对地震对斜交梁桥碰撞效应的影响进行了研究。首先介绍了斜交梁桥的结构特点以及地震时的动力学问题，随后分析了地震时斜交梁桥的碰撞效应产生原因以及可能影响结果。接下来，针对碰撞效应进行了三维有限元数值模拟和实验研究，验证了碰撞效应的存在以及其对斜交梁桥的破坏程度的影响。最后，针对斜交梁桥在地震中的安全问题提出了对策，并对研究结果进行了总结。

关键词：近断层地震；斜交梁桥；碰撞效应；有限元；数值模拟

Abstract

Thispaperstudiestheimpactofearthquakesonthecollisioneffectofskewgridbridges.Firstly,thestructuralcharacteristicsofskewgridbridgesandthedynamicproblemsduringearthquakesareintroduced.Then,thecausesofcollisioneffectsduringearthquakesonskewgridbridgesandpossibleimpactresultsareanalyzed.Next,three-dimensionalfiniteelementnumericalsimulationandexperimentalstudiesareconductedtoverifytheexistenceofcollisioneffectsandtheirimpactonthedamagelevelofskewgridbridges.Finally,countermeasuresareproposedforthesafetyissuesofskewgridbridgesinearthquakes,andtheresearchresultsaresummarized.

Keywords:near-faultearthquakes;skewgridbridge;collisioneffect;finiteelement;numericalsimulationTheresultsofthestudyshowthatthecollisioneffectofnear-faultearthquakescansignificantlyincreasetheseismicresponseofskewgridbridges.Thiseffectarisesfromthedynamicinteractionbetweenthebridgedeckandthepylonsduringanearthquake,whichcanleadtohigh-frequencyvibrationsandincreasedseismicdemandsonthestructure.Thenumericalsimulationandexperimentalstudiesconfirmthatthecollisioneffecthasasignificantimpactonthedamagelevelofskewgridbridges,particularlyforstructureswithhighskewangles.

Tomitigatethesafetyissuesassociatedwiththecollisioneffect,severalcountermeasuresareproposed.Theseincludetheuseofhigh-dampingseismicisolationsystemstomitigatethedynamicinteractionbetweenthebridgedeckandthepylons,andthedeploymentofenergydissipationdevicesatkeylocationsalongthebridgedecktoabsorbseismicenergy.Inaddition,modificationstothestructuraldesignanddetailingofskewgridbridgescanbemadetoimprovetheoverallseismicperformanceofthestructureandmitigatetheeffectsofthecollision.

Insummary,thestudyhighlightsthesignificantimpactofthecollisioneffectontheseismicresponseofskewgridbridgesduringnear-faultearthquakes.Thefindingsofthisstudycanbeusedtoinformthedesignandretrofitofexistingstructuresandcontributetothedevelopmentofmoreresilientinfrastructureinearthquake-proneregionsFurthermore,thestudyemphasizestheimportanceofconsideringthecollisioneffectasacrucialfactorintheseismicdesignofskewgridbridges.Developingrobustdesignapproachesthataccountforthepotentialdamagescausedbythecollisioncanhelpinminimizingtheoverallseismicvulnerabilityofthesestructures.

Additionally,thestudysuggeststhatretrofittingexistingskewgridbridgestoincorporaterobustdesignfeaturescansignificantlyenhancetheirseismicresilience.Retrofitoptionssuchasstiffeningthebridgedeck,introducingaseismicisolationsystem,andimprovingthestructuraldetailingcanhelpinmitigatingthecollision-induceddamagesandimprovingtheoverallperformanceofthebridgeduringearthquakes.

Moreover,thestudyhighlightstheneedformorecomprehensiveexperimentalandnumericalinvestigationsofskewgridbridgesundernear-faultearthquakesconditions,togainabetterunderstandingofthecomplexinteractionbetweenthecollision,near-faulteffects,andthebridgeseismicresponse.Thesestudiescanhelpindevelopingmoreaccuratedesignguidelinesandretrofitstrategiesthateffectivelyconsiderthemultipledamagemechanismsaffectingthebridgeduringearthquakes.

Inconclusion,thestudydemonstratesthatthecollisioneffectcansignificantlyaffecttheseismicresponseofskewgridbridgesduringnear-faultearthquakes.Engineeringsolutionssuchasincorporatingrobustdesignfeaturesandretrofittingexistingstructurescanhelpinimprovingtheoverallseismicperformanceofthesecriticalinfrastructureassets.Thefindingsofthisstudycancontributetothedevelopmentofmoreresilientinfrastructureandasaferbuiltenvironmentinearthquake-proneregionsSkewgridbridgesarecriticaltransportationstructuresthatprovidepassageoverwaterways,valleys,andotherobstacles.Thesebridgesarecommonlyusedinearthquake-proneregionsduetotheiraestheticandfunctionaladvantages.However,theyaresusceptibletodamageandfailureduringstronggroundmotionsduetotheircomplexgeometryandconfiguration.Near-faultearthquakes,inparticular,cancauseextensivedamagetothesestructures,leadingtosignificanteconomiclossesandsocialdisruption.

ThestudybyDingetal.highlightedtheimportanceofconsideringthecollisioneffectintheseismicdesignandanalysisofskewgridbridges.Thecollisioneffectreferstotheimpactofthediagonalbeamsonthemaingirderduringseismicloading.Thiseffectcancauseadditionalstressesanddeformationsinthebridgecomponents,leadingtostructuralandfunctionaldamage.

Theresearchersconductednumericalsimulationsandlaboratoryexperimentstoinvestigatethecollisioneffectontheseismicresponseofskewgridbridges.Theyfoundthatthecollisioneffectcancausesignificantincreaseinthepeakresponseofthebridge,particularlyintermsofbendingmoment,shearforce,anddisplacement.Theeffectwasmorepronouncedinbridgeswithlargeskewanglesandlowaspectratios.

Thestudyalsodemonstratedthatincorporatingrobustdesignfeatures,suchasstrengtheningthediagonalmembersandincreasingthedepthofthemaingirder,canhelpinmitigatingthecollisioneffectandimprovingtheseismicperformanceofskewgridbridges.Retrofittingexistingstructureswiththesefeaturescanalsohelpinenhancingtheirresilienceanddurability.

Thefindingsofthisstudyhaveimportantimplicationsforthedesign,construction,andmaintenanceofskewgridbridgesinearthquake-proneregions.Theyhighlighttheneedforconsideringthecollisioneffectintheseismicdesignandanalysisofthesestructuresandforincorporatingappropriatedesignfeaturesandretrofittin