为了给近断层设计谱的确定提供新的方法和参考依据,考虑场地条件的影响,分析了53条具有典型近断层方向性效应特征的地震动记录的双规准组合反应谱的特征.相比传统的地震动加速度、速度和位移反应谱,组合反应谱的谱值与地震动的幅值相关性更强;双规准组合谱具有更低的统计变异性.最后,给出了基于双规准组合谱特征的近断层区场地相关设计谱模型.
Aiming at providing new method and reference for the construction of near-fauh design spectra, characteristics of bi-normalized combined spectra of 53 typical near-fault directivity effect ground motions are analyzed by considering the influence of site condition. Results show that the bi-normalized combined spectrum exhibits the highest correlation with the amplitudes of ground motions, and the lowest statistical variability, compared with those of acceleration spectrum, velocity spectrum and displacement spectrum. Finally, site- depended design spectral models for near-fault region are suggested based on features of hi-normalized combined response spectra.