The Great Hanshin-Awaji Disaster (Kobe Earthquake) caused huge damages to buildingstructures, especially to old or non-engineered buildings. It has strongly beenrecognized that the strengthening of these seismic vulnerable buildings is one of urgentissues for the reduction of earthquake disaster. Thus, in response to the precious lessonsfrom the Kobe Earthquake, the Japanese government enacted "the Law for Promotion ofSeismic Retrofit of Buildings, " in December 1995. In accordance with the law, existingbuildings of more than certain floor area for public use shall be retrofitted to satisfy theseismic performance level equivalent to the current code requirement at the time ofrenovation.