@ ŒfÚŽGŽi˜ajF “ú–{’nkHŠwƒVƒ“ƒ|ƒWƒEƒ€u‰‰W VolF 5Šª ”NF 1978”N •ÅF 257-264•Å ’˜ŽÒi˜ajF - ƒ^ƒCƒgƒ‹i˜ajF - ´˜^i˜ajF
- ƒL[ƒ[ƒhi˜ajF - ŒfÚŽGŽi‰pjF PROCEEDINGS OF JAPAN EARTHQUAKE ENGINEERING SYMPOSIUM ’˜ŽÒi‰pjF Yoshimasa KOBAYASHI, Toshiro FUJIWARA ƒ^ƒCƒgƒ‹i‰pjF GROUND MOTIONS OF LONGER PERIODS IN STRONG EARTHQUAKES ´˜^i‰pjF
Seismograms in the Niigata earthquake 1964, the Tokachioki earthquake 1968 and its largest aftershock registered by JMA-type strong-motion seismographs are analysed. Procedures for data processing are described. Response spectra of the seismograms are computed for periods from 2 to 50 seconds, and the results are compared with those of SMAC records at almost the same sites in the common period range, yielding a satisfactory agreement. The frequency of relative-velocity spectra are almost flat in the period range computed, which fact implies ¡-square law in that range. Levels of the spectra at several sites suggest a strong effect of site conditions, and as a result a formula of the level as a function of the earthquake magnitude, distance, etc. could not be determined. ƒL[ƒ[ƒhi‰pjF - ‹LŽ–‹æ•ªF - ‹æ•ª @@@ˆÏˆõ‰ï˜_•¶W