INOUE Hiroshi Disaster Prevention Research Institute, Earthquake Research Department., Principal Senior Researcher, 地震研究部, 室長 (80450253)
MOGI Toru Hokkaido University, Faculty of Science, Professor, 大学院・理学研究院, 教授 (80182161)
HIROSHI Kuramoto Toyohashi Institute of Technology, Department of Architecture and Civil Engineering, Associate Professor, 工学部, 助教授 (20234544)
YAMAZAKI Fumio Chiba University, Faculty of Engineering, Professor, 工学部, 教授 (50220322)
YOSHIMINE Mitsutoshi Tokyo Metropolitan University, Department of Civil and Environmental Engineering, Accociate Professor, 都市環境科学研究科, 助教授 (80251338)
Due to the earthquake of magnitude (M) 6.3 of the Central Java, Indonesia earthquake, more than 5,700 casualties and 140,000 collapsed houses were produced on May 27, 2006. The feature of this earthquake damage is that very serious human and structural damage has occurred compared to its small earthquake size. Therefore, our focus of this research is to investigate the cause of such a devastating damage to people and structures from the view point of the source location, source characteristics, soil amplification, and fundamental response characteristics of structures. The research troop is divided into five small teams, namely, the earthquake and ground motion team, the soil structure team, the damage outline and human loss team, the building damage team, and the civil engineering structure damage team, and they perform field surveys in the country and laboratory analysis afterward.
First, by the earthquake and ground motion team, aftershock observation was carried out and the area of
aftershock was determined. The detailed focus mechanism was inverted using earthquake observation data. As a result, the source region was probably located directly under the damage concentration area, or its west side. This means that the causative fault is not connected to the Opak fault.
As for the ground structure, we investigate the sedimentary basin structure by using geomagnetism and a telluric current method and we delineate the shallow subsurface layer structure by microtremor measurement. As a result, it turned out that the spatial difference of damage mainly depends on the shallow subsurface layer structure.
As for the building damage, wide scale damage distribution was delineated by the satellite imagery analysis. Moreover, the earthquake damage analysis is made based on the actual enforcement of local laws and actual condition of construction, and the earthquake resistance of the building made of reinforced concrete and bricks was investigated in detail. We also investigated civil engineering structure, ground failure, and lifeline damage Less