Seismic Damages of Retaining Walls and Building Sites in Genkai Island by West Off Fukuoka Prefecture Earthquake 2005

摘要

In West Off Fukuoka Prefecture Earthquake 2005, severe earthquake with magnitude 7.0 hit Genkai Island, causing several damages at the residential site of the island. Genkai Island is located in the north of Fukuoka city, Kyushu Island; very near to the epicenter of the event. Many houses, buildings, retaining walls and other structures were damaged due to ground deformation caused by seismic action. The building site was constructed on the mountain slope, for these reason the existence of cut and fill sections are common on the island. Immediately after the earthquake, a lot of residents took refuge from the damage area on the slope to temporary houses built on the sea side area. Damaged houses and retaining wall were left as it is for more than one year to make new land development and city planning. The purpose of this study is to focus on the damages on the retaining walls and building sites. In the field study, the soil tests and the damage investigations were carried out. In this research, the feature and tendency of disasters of retaining walls and so on were summarized.