学会誌「自然災害科学」

地震時の人的被害と地動加速度の関係に関する検討

Relationship between Seismic Acceleration and Casualties due to Earthquakes

呂 恒倹*・宮野 道雄**

Heng Jian LU* and Michio MIYANO**

Abstract

Before 1960, casualties during earthquakes were mainly due to the structural damage of houses and until recently the damage rate of houses has been used as a parameter in the investigation of human casualties during earthquakes. But after l960, the causes of casualties became more and more diversified, and the use of damage of houses as a parameter to evaluate human casualties in recent earthquakes began to create some problems.

This paper tries to investigate the relationship between casualties and the intensity of ground motion in the Great Kanto, Oga, Tonankai, Fukui and 1952 Tokachi-oki earthquakes which occurred before 1960, and the 1968 Tokachi-oki, Izuhanto-oki, Oitaken-chubu, Izuoshima-kinkai and the 1978 Miyagiken-oki earthquakes (all of which occurred after 1960), as samples. The rates of death and injury caused by earthquakes are discussed in relation to the seismic accelerations estimated from the situation of tombstones overturned during the earthquakes.

It is indicated that the correlation between seismic acceleration and the rates of death caused by earthquakes after 1960 is not very strong because of the relatively low amount of deaths, but the rates of injury caused by earthquakes occurring before and after 1960 all had high correlation with seismic acceleration. This investigation also shows that there was nearly no difference in the correlation of injury rates to seismic acceleration among these 10 earthquakes that occurred in the two different periods. Therefore it might be possible to use seismic acceleration as a parameter for macro-prediction of injury rates in earthquakes.

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