Journal of Natural Disaster Science

RESPONSE SPECTRA OF LONG-PERIOD GROUND MOTIONS OBTAINED BY MENDING SATURATED RECORDS FROM A LOW-MAGNIFICATION SEISMOGRAPH

Yoshikazu YAMADA
Professor, Department of Civil Engineering, Kyoto University, Kyoto
Shigeru NODA
Associate Professor, Department of Social Systems Engineering, Tottori University, Tottori
Saburo SHIMADA
Manager, Technical Research Institute, Maeda Corporation, Tokyo
and
Takaharu YOSHIDA
Senior Research Engineer, Technical Research Institute, Maeda Corporation, Tokyo

(Received 17 July 1991 and in revised form 28 December 1991)

Abstract

Because valuable information concerning the seismic design of structures is hidden in saturated records, a shaking table test is proposed as an improved method to mend the Japan Meteorological Agency's (JMA's) low-magnification seismograms. For engineering purposes, this method mends a saturated seismogram with an error of less than 10%. Seven JMA's saturated records obtained during the 1968 Tokachi-oki, the 1978 Miyagiken-oki and the 1983 Nihonkai-chubu earthquakes were mended by this method. Some of the mended displacement seismograms give much higher response spectra than do the design values for long-period (4 to 15 sec) structures.

Key words

long-period ground motion, response spectra, low-magnification seismograph, saturated records, mending method, shaking table test