Vol.3-1
 
アンケート調査による地震震度と都市表層地盤地質との関係
Seismic Intensity Distribution by a Questionnaire Survey and Its Relation to Subsurface Structures −A Case Study in Kumamoto City−
宮崎 雅徳* ・ 久保寺 章**
Masanori MIYAZAKI* and Akira KUBOTERA**

 

Abstract
 Relation between seismic intensity and surface structure in site were examined.
 The earthquake on June 28, l977, which occurred at 10 km northwest of Kumamoto, recorded seismic intensity IV in JMA (Japan Meteorological Agency) scale in and around Kumamoto City. Immediately after the earthquake, the questionnaire sheets were delivered to the persons live in and around Kumamoto City and it makes an estimate of the intensity distribution in detail. The results are:
 (a)The difference of the seismic intensities related to the magnitude and epicentral distance, and the local intensity vary with the geological age.
 (b)The seismic intensity depends on the surface structure at the site; for example, those in relative unstable place of alluvial formation as the reclamation land recent are, on an average, about 0.7 greater than those expected from an empirical formula. On the contrary, those in stable place in the diluvial formation are 0.6 less than those.
 (c)Using to correlation of local intensity to those with empirical formula, the differences(△I)show the characteristic of surface structure in site. So, it may be able to make the sesimic micro zoning map with △I.


*九州東海大学工学部
Faculty of Engineering, Kyushu Youkai University
*京都大学理学部
Faculty of Science, Kyoto University


日本自然災害学会