STUDY ON ISOLATED COLUMNS SUPPORTING UPPER SHEAR WALLS SEVERELY DAMAGED DURING THE GREAT EAST JAPAN EARTHQUAKE

Estimation of the subjected axial load during the earthquake and the axial load capacity

Abstract

The junior high school building investigated was a 3-story reinforced concrete (R/C) building built in 1966 in Motomiya city. The building suffered a great deal of damage during the Great East Japan Earthquake. Frames in the longitudinal direction were moment resisting frames with no shear walls. On the other hand the shear walls of two frames in the span direction were not continuous and isolated columns of the first floor supported all axial load generated by walls of upper floors. The slabs around the center of the building in the second floor had fallen due to the shear and axial failure of columns of the first floor. These columns were isolated columns in the first floor supporting upper shear walls. In this study the failure mechanism of these columns was discussed.