简介：Mostpublishedstudiesoninelasticearthquakeresponseofnon-symmetricbuildingsarebasedonsimplifiedinelastic,highlyidealizedmodels,whilegeneralconclusionsregardingtheinelastictorsionalresponseofmultistorybuildingarestilllacking.Thispaperaimstoprovideausefulcontributioninthestudyofthetorsionalresponseofrealirregularbuildings.Tothisaim,themanuscriptreportsthecomprehensivestudyontheseismicvulnerabilityofanirregularRCbuilding:thehospitalbuildingofAvezzano(L’AquilaItaly).Forthismulti-storybuilding,whichisirregularinbothplanandelevation,theapplicationofnonlinearstaticevaluationproceduresisbynomeansstraightforward.Thestudyproposesanonlinearstaticprocedurebasedonpushoveranalysisunderthemultimodaldistributionoflateralloadsandacapacityspectrummethod.Thispushoverprocedureaccountsformassdistribution,highermodescontributionandmode-shapescorrelation.Furthermore,duetoitsnon-iterativefeature,itavoidsproblemsofnon-convergenceandmultiplesolutionsoftheconventionalcapacityspectrummethod.Appliedtoarealcasestudy,theprocedureisusedtoinvestigate,ina3Dplanirregularbuilding,thesensitivityoftorsionalinelasticresponsetolateralforcedistribution,highermodescontribution,accidentaleccentricityandcontrolledpointformonitoringthetargetdisplacement.