Study on characteristic parameters of near-fault response spectrum

883 vertical earthquake records within the fault distance of 100 km were selected to study that whether the vertical design response spectrum characteristic parameter should be also used for the seismic design of engineering structure in near-fault region. Considering the influence of site conditions, fault distance and velocity pulse characteristics, the platform value, the first turning point period, the characteristic period, and the attenuation index of the dynamic amplification coefficient spectrum were studied respectively. This study concludes: the platform value, the first turning point period, the characteristic period, and the attenuation index are affected by site condition, fault distance, and velocity pulse characteristics. Chinese building seismic design code takes the platform value, the first turning point period, and the attenuation index as fixed values which may not be reasonable, and it should take into account the influence of site condition and fault distance. For the vertical ground motions in near-fault region, the platform values, the first turning point period, and the characteristic period of the dynamic amplification coefficient spectrum should be reasonably increased to improve the safety reserve of the engineering structures in near-fault region.