Development and present status of seismic evaluation and seismic retrofit of existing reinforced concrete buildings in Japan

This paper describes the development and present status of seismic evaluation and seismic retrofit of existing buildings mainly for low-rise and medium-rise reinforced concrete buildings in Japan. First, since the seismic evaluation of existing buildings has close relationships with the seismic design of new buildings, a brief history of the development of seismic design, seismic evaluation, and seismic retrofit is provided in terms of major earthquake disasters mostly in Japan and associated with some major events in the U.S. Then, the development of seismic evaluation and retrofit is reviewed, focusing on the items in which the author has been deeply involved. This provides insight into previous earthquake damage, methodologies for seismic evaluation, the basic concept of the Standard for Seismic Evaluation of Existing Reinforced Concrete Buildings, studies on the demand criteria for seismic safety, and the present status of seismic evaluation and retrofit. Finally, the typical methods of seismic retrofit and some examples of retrofitted buildings in Japan are explained.