A Comprehensive Re-examination of the Geiyo Earthquake Disaster, 1906

本研究以1906年6月2日的广岛市-库尔-松山地区地震灾害为研究对象，从多个研究领域的多角度，综合考察地震灾害对该地区的影响，以期通过跨学科的合作，促进区域灾害预防。首先，通过文献调查和问卷调查，收集了有关艺阳地震灾害的资料。收集到的一些资料，包括报纸文章、侦察报告、各组织的档案等，已编为最后报告的附录，以供进一步研究。在震源区明田海域附近进行了声纳调查，以确定引起Geiyo地震的海床断层。没有发现海床断层，证明海啸不是由地震引起的。采用有限元法进行了断层破裂模拟，并对小断层破裂过程进行了综合。据日本气象厅估计，广岛-库尔县的地震烈度为V至VI级。对灾区的地面情况进行了大量的调查。通过微震测量和多反射理论分析，确定了广岛和库雷地区地面的主导期。分析了松山地区的液化可能性，得出了没有液化的结论，这与没有发现液化证据的事实相吻合。此外，还发明了一种便于操作的冲积层土块取样装置“振冲仪”。从震害分析和建筑物震害评估两方面对震害预测进行了基础性研究。为了确定最需要关注的震区，对广岛市的地震灾害进行了分析，结果表明，aki和iyonada地区的地震活动对广岛市的地震灾害有很大的贡献。对木结构进行了动力响应分析，并对钢筋混凝土结构进行了损伤率估算，重点研究了土体放大效应。少

In this study, damage to Hiroshima-Kure-Matsuyama region due to the Geiyo earthquake of June 2, 1906 was re-examined from multi-viewpoints of various research fields in a comprehensive manner, aiming at promotion of regional disaster prevention through the inter-disciplinary collaboration.Firstly, in order to collect materials on the Geiyo earthquake disaster, literature survey and questionnaire investigation were conducted. Some of collected items, including newspaper articles, reconnaissance reports, archives of various organizations, etc. have been compiled as appendices of the final report for further study.Sonar investigation was carried out around the epicentral region in Aki-nada sea area to identify sea-bed fault causing the Geiyo earthquake. No sea-bed fault could be found, which proved that tsunami was not induced by the earthquake. Fault-rupture simulation using FEM method and synthesis of small fault-rupture process was also performed. Seismic intensity at Hiroshima-Kure re … More gion was estimated as V to VI on the JMA scale.Much effort was devoted to the investigation of ground condition of the disaster-stricken area. Predominant period of ground in Hiroshima and Kure was determined by conducting both measure of microtremors and theoretical analysis employing multi-reflection theory. Liquefaction possibility in Matsuyama was analyzed and it was concluded that no liquefaction occurred, which coincided with the fact that no evidence of liquefaction was found. Furthermore, "vibro-corer" was invented for future use as an easy-to-operate device to sample soil piece of alluvium layr.Fundamental studies on earthquake damage prediction were carried out in terms of seismic hazard analysis and damage assessment of buildings. In order to identify most-concerned seismic region, seismic hazard of Hiroshima city was analyzed, which showed the seismic activity in Aki-and Iyo-nada area had substantial contribution to the seismic hazard in Hiroshima. Dynamic response analysis of wooden structures and damage rate estimation of reinforced concrete structure were performed with emphasis on the effect of soil amplification. Less