The Comparision of Probabilistic Seismic Demand Models Estimated Through the Incremantal Dynamic Analysis and the Use of Scaled Ground Motion Records

A reliable estimation of seismic demand is an essential part of recently developedperformance based design engineering. In this estimation a Probabilistic Seismic DemandModel (PSDM) must be implemented to predict the mean value of the demand at thespecific value of intensity measure parameter. In this paper it is tried to perform acomparison between the PSDMs which are obtained through the results of nonlineardynamic analysis subjected to a set of scaled records with the models determined throughthe results of incremental dynamic analysis in order to find the proper value for the scalefactor. The results show that model estimation using only a single scale factor is achievablein the case of 3 and 6-storey frames and for 9, 12 and 15-storey frames, the combination of scaled and un-scaled records can lead to reliable estimation of parameters.