Calibrating method for seismic response spectra based on niche genetic algorithm

A new method,niche genetic algorithm(NGA),is adopted to calibrate the seismic response spectra and a verification standard for calibrating the seismic response spectra is proposed.The characteristic parameters of seismic response spectra include the peak of ground motion,the first turning point of spectrum,the second turning point of spectrum,the flat height of spectrum and the attenuation index,and so on,and therefore the calibration of the seismic response specta is a problem of multi-parameter optimization.NGA,with the ablitity of global optimization of multi-parameter,is used to solve this problem,aiming at the least mean standard error of spectral values at appointed periods.A new verification method proposed is that the seismic response spectra with given characteristic parameters are used to verify the effectiveness of the method,that is,the seismic response spectra with given characteristic parameters are calibrated and the errors between the calibrated characteristic parameters and the given ones are smaller than the appointed precision.Three pieces of the calculated response spectra for one real site are calibrated as an application example.The obtained results show the effectiveness and efficiency of the proposed method.