Comparison between floor response spectra from time history analysis and direct transformation of ground response spectra

Several components and piping systems of the nuclear power plant (NPP) Beznau (Switzerland) have been reanalysed for seismic loading. The floor response spectra (FRS) used as input for these analyses were obtained from a time history (TH) analysis. For comparison purposes, in a second analysis of the auxiliary buildings, use was made of a probabilistic method, which generates floor response spectra directly from the base spectra. In this paper attention is drawn to the practical problems arising in the application of the latter. (orig.)