Research on the Influence of the Target Spectrum and Amplitude Scaling Method on the Dynamic Time History Analysis Results of a High-Rise Building Structure

This study addresses the critical need for region-specific ground motion selection methods in the Xi’an area by proposing a novel Peak Ground Acceleration (PGA)-based target spectrum, developed through the relationship between PGA and response spectrum attenuation. Based on the relationship between the peak ground acceleration (PGA) and the attenuation of the response spectrum, a PGA target spectrum applicable to the Xi’an area was studied. Using the PGA and code-specified Standard Spectrum as the target spectrum, earthquake records were selected and their amplitudes scaled by employing various methods, including fundamental period scaling, average spectral ratio scaling, equal spectral intensity scaling, minimum squared error scaling, and minimum moving average scaling. Based on the 70 ground motion records obtained from the five scaling methods applied to the two target spectra (grouped into 10 distinct sets), the dynamic time history analysis was conducted for a frame-core tube structure; the effects of different scaling methods and different target spectra were investigated on the dispersion of floor displacement, interstory drift ratio and interstory shear. The results show that the spectral value of the PGA target spectrum at the peak is 54% higher than that of the code-specified spectrum, while in the long-period range, the acceleration values of the PGA target spectrum are comparatively smaller, only about 50% of those of the code spectrum. For structural response, the code target spectrum is more conservative compared with the PGA target spectrum, and the minimum moving average method is the least sensitive to different target spectra. This work offers preliminary insights that may contribute to the optimization of ground motion selection in regionally tailored seismic design practices.