地震動と防災

Abstract

The seismic characteristics of structures will be determined by considering the design earthquakeduely selected to the site. In this paper, the relations between the earthquake motion and the earth-ground, source process and path are briefly discussed. From the observational results of strong mo-tions, peak accelerations are obtained in terms of magnitude and epicentral distance, however, thedeviations from the regression curve are found to be significant. Therefore, this variability has to beconsidered in the prediction of strong motion.The topographical irregularity and the ground structure play important role on the determina-tion of design earthquake. Some experimental and theoretical methods are reviewed. In orderto mitigate earthquake hazard, the mechanisms that control strong ground motion have to bestudied from the points of view of both seismology and engineering. The analysis of past earthquakedamage together with estimation of strong motion will be useful to define measures for the disasterprevention.