Casestudiesarepresentedfortwoconcretelinedchannelsshakenbystronggroundmotionsduringthe1994Northridgeearthquake,thehighspeedchannel(HSC)andbypasschannel(BC),ontheLosAngelesDepartmentofWaterandPower'sVanNormanComplex.Performancesofthesetwochannelsastheypassthroughdifferentsubsurfacematerialsidentifyseveralimportantseismicaspectsandthecriticalroleofgeotechnicalearthquakeengineeringinassessingchannelbehaviors.Preliminaryevaluationsusingdetailedmappingofchannelcracks,permanentgroundmovements,subsurfaceprofiles,andnearbystronggroundmotionrecordingsfromthe1994earthquakeshowthatthechannellinersmayhavebeendamagedfrombothtransientmotionsandpermanentgroundmovements.Damagefrompermanentgrounddeformationsisobviousbyobservation;thereforesimplifiedanalysesarepresentedonlyfortransientmovements.SitespecifictransientresponseanalysesareperformedtoprovideaninitialassessmentofthedifferingeffectsfromtransientandpermanentgroundmovementsonHSCandBClinerdamage.Thesecasestudiesarehelpfulforintroducingthepotentialforlifelinedamagefromtransientmovementswithinzonesofpermanentgroundmovement,aconceptnotwellunderstoodintheearthquakeengineeringcommunity.
