국내 속도 지반운동을 이용한 수직 응답스펙트럼 특성 분석

Abstract

The vertical velocity response spectra, not acceleration, using the observed ground motion from the recent 5 macro earthquakes, larger than 4.8 in magnitude, were analysed and then were compared to both the seismic design response spectra (Regulatory Guide 1.60, 1968), applied to the domestic nuclear power plants, and the Korean Standard Design Response Spectrum for general structures and buildings(1997). 51 vertical ground motions were used and vertical response spectra were normalized with respect to the peak velocity value of each ground motion. The results showed that response spectrum has strong dependency on natural frequency or natural period. The results also showed that the vertical velocity response spectra revealed higher values for frequency bands below approximately 2 - 3 Hz than Regulatory Guide 1.60(1968), which were scaled to 0.1 g. The results were also compared to the Korean Standard Response Spectrum(500 years of recurrence rate) for the 3 different soil types(SC, SD, and SE) and showed that the vertical response spectra revealed higher values for the frequency bands above approximately 0.2 second (5Hz) than the Korean Standard Response Spectrum. Through the qualitative improvements and quantitative enhancement of the observed ground motions, it is necessary that the conservation of vertical seismic design response spectrum should be considered more significantly for the frequency bands suggested above.