The uncertainty in shape parameter predictions of seismic design spectra for nuclear power plant

Aiming at the uncertainty of design spectrum raised by the construction methods, a comparative study is conducted in which different methodologies performed calculations of seismic response spectra using the same set of ground motion data from recent large earthquakes. The results of the research allowed some estimates to be made of the scaling method and model uncertainty involved in these calculations. These results were compared with the uncertainty derived from the proposed spectrum of a double-parameter-based bi-normalized response spectrum (DPBNS) approach. It is concluded that the sources of uncertainty that the results reflected are mainly impacted by the spectral type, scaling parameters, as well as imposed fixed conditions adopted in the calculations, for the scaling of the design spectra. Then, a discussion is provided on the limitations of these predications, in particular, of the approaches adopted in the construction of seismic spectra.