简介：Adualisolationproblemforrotatingmachinesconsistsofisolationofhousingstructuresfromthemachinevibrationsandprotectionofmachinesduringanearthquaketomaintaintheirfunctionality.Desirablecharacteristicsofmachinemountsfortheabovetwopurposescandiffersignificantlyduetodifferenceinnatureoftheexcitationandperformancecriteriainthetwosituations.Inthispaper,relevantresponsequantitiesareidentifiedthatmaybeusedtoquantifyperformanccandsimplifiedmodelsofrotatingmachinesarepresentedusingwhichtheserelevantresponsequantitiesmaybecalculated.Usingrandomvibrationapproachwithastationaryexcitation,itisshownthatsignificantimprovementinseismicperformanceisachievablebypropermountdesign.Resultsofshakingtableexperimentsperformedwitharealisticsetupusingacentrifugalpumparepresented.Itisconcludedthatasolutiontothisdualisolationproblemliesinasemi-active.mountcapableofswitchingitspropertiesfrom‘operation-optimum'to‘seismic-optimum'attheomsetofaseismicevent.