Study On Earthquake Response Spectrum Considering Wawe-passage Effect

In this paper, the concept of seismic response spectrum base on the background of the multiply-supported SDOF system considering wave-passage effect is developed.And the influence of wave-passage effect on the seismic dynamic response of long-span structure is studied in depth.Firstly, the motion equation of the multiply-supported single-degree-of-freedom(SDOF) system under non-uniform excitation is established. By solving the system’s motion equation, the time domain analytical expression of the absolute acceleration response considering wave-passage effect is obtained. Furthermore, the Fourier system’s amplitude spectrum under wave-passage excitation is obtained, and it could be expressed by the corresponding uniform excitation. The results of theoretical derivation shows that the wave-passage effect could reduce the multiply-supported SDOF system’s absolute acceleration response, which also could shows that the wave-passage effect could reduce the system’s seismic dynamic response.After that, the concept of traveling wave seismic response spectrum based on classical seismic response spectrum is proposed. The seismic response spectrum considering wave-passage effect could be calculated by the system’s absolute acceleration response analytical expression.As an example, for different velocities of wave-passage, the four-supported SDOF system response spectra is calculated. The definition of the response spectrum ratio shows that the wave-passage effect will reduce the value of the seismic response spectrum, and this is consistent with the result of the frequency domain analysis.Finally, based on the 4438 ground motion records from the PEER NGA Database, the traveling wave seismic response spectra of different types of sites are analyzed statistically, the mean and standard deviation of the traveling wave response spectrum are calculated. The results show that the dispersion of the traveling wave seismic response spectrum increased with the increasing period.This study provides a theoretical basic method for the further development of the mode decomposition response spectrum method considering wave-passage effect for long-span structures, and provide a reference for the seismic design of long-span structures.