SIMULATED EARTHQUAKE GROUND MOTION COMPATIBLE WITH HIGH-DAMPING TARGET SPECTRA

抄録

This paper presents a new method of generating the time-history waveforms which are compatible with multiple-damping target spectra. To assess the structural integrity of buildings and reactor buildings, time-history response analyses are conducted using simulated earthquake ground motions which are matched with the target spectra. The damping factors of simulated earthquake ground motions are defined as approximately from 0.01 to 0.05. These damping factors differ from damping factors applied to seismic isolated structures because the seismic isolated structures use the damping forces corresponding to the damping factors of approximately 0.2 to 0.4. The time-history waveforms which are matched with the target spectrum with a damping factor of 0.05 can lead to large variations in the seismic responses for the seismic isolated structures. The iteration schemes to suppress the large variations in the seismic responses have been developed by employing the corrective waveforms. However, these iteration schemes which are capable of being applied to structures with high damping factors, such as the seismic isolated structures, have not been developed yet. This is because the frequency intervals of corrective waveforms significantly affect the convergence to the target spectra with the increased damping factor. Therefore, this paper presents a new type of method focused on the frequency intervals of corrective waveforms and demonstrates the effectiveness of this method by generating the time-history waveforms which are compatible with multiple-damping spectra including the high-damping factors.