RELATIONSHIP BETWEEN SEISMIC CAPACITY AND DAMAGE OFREINFORCED CONCRETE SCHOOL BUILDINGS IN JAPAN THATHAVE EXPERIENCED THE 2001 GEIYO EARTHQUAKE

摘要

After the 1995 Hyogoken-Nanbu earthquake, the seismic capacity evaluation of public buildings becomesprevalent in Japan. Since school buildings are used as local evacuation centers after disastrousearthquakes, the verification of their seismic capacity is a pressing need. However, due to the lack ofsupportive funds, many school buildings still remain unchanged. The relationship between the structuraldamage and seismic capacity has been identified from various pervious studies. However, there is noreliable relationship yet mainly due to difficulty to grasp information on damaged and undamagedbuildings. In this study, the seismic capacity evaluation for the most school buildings in the affected areaof the March 24, 2001 Geiyo earthquake, Kure City, Hiroshima Prefectur, was conducted. We found thatthe seismic indices of school buildings in Kure City are generally low compared with the results obtainedfor other prefectures in Japan. Therefore in this area, larger structural damage is expected than that ofother regions for a same magnitude event. In the 2001 Geiyo earthquake, many old buildings weredamaged. Many school buildings suffered from minor to moderate damages since the level of inputmotion was one in which the structures start to exhibit inelastic responses. Larger levels of damages wereobserved for the buildings constructed before 1971, especially for those having low concrete strengths. Agood correlation between the seismic index (IS) of structures and their damage grades is observed whenthe sites are classified by the predominant period.