A study of calibrating seismic design response spectrum based on high-intensity ground motion records

The seismic design response spectrum is a vital parameter for determining the potential seismic load of the engineering structure. Differential evolution algorithm (DE) with a novel hybrid mutation operator is utilized to calibrate the spectral parameters in order to enhance iteration efficiency. This study calibrates the seismic design response spectrum for China based on the Chinese seismic intensity scale and compares the results with the Code for Seismic Design of Buildings (CSDB2010).The calibration spectra are based on strong ground motion records with destructive power exceeding the Chinese seismic intensity 7 and above. The characteristics of the calibration spectral parameters are analyzed and subsequently compared with the design spectra of the Code for Seismic Design of Buildings (CSDB2010). It is found that: Increasing the number of iterations can enhance the fitting goodness of DE between the calibration spectrum and the record response spectrum. The average site characteristic period (T_g) for rock and hard soil site conditions (Class I and II) is greater than the T_g specified in CSDB2010. The average T_g for intensity 10 + is greater than the average T_g for intensity 7, 8, and 9. T_g increases with the seismic intensity. The average spectra platform value (β_max) from this study gradually approaches the β_max in CSDB2010 as the intensity increases. The average attenuation index (γ) at different intensities of this study is greater than γ in CSDB2010.