Preservation and Seismic Retrofit of the Traditional Wooden Buildings in Japan
Kenichi Katagihara

The structural system of Japanese traditional buildings is focused as a typical case of 'temporal design' in the architectural field. A series of the studies aims to evaluate the dynamic performance of the traditional wooden structure as well as that of each resisting part. Vibration tests of a full-scale model subject to strong ground motion were carried out on the shaking table. Also, in this paper is shown an analytical method for seismic evaluation as the earthquake response analysis, which clarify the seismic characteristics of the traditional wooden structure quantitatively. On the basis of dynamic performance, which is characterized by stiffness, ductility and damping capacity, the author shows the seismic safety criteria and makes a proposal for the preservation and seismic retrofit of the traditional wooden buildings. Regarding the wooden structure, columns or beams are not jointed rigidly, unlike those of the reinforced concrete or steel structures, which triggers great deformation at joints during the earthquake. Focusing the connecting part, viscous dampers are installed in the wooden frames to increase the original damping capacity as useful device for the retrofit works. In this respect, this paper presents the upgrade effects on the cultural property buildings.

Key words:
traditional wooden buildings, seismic characteristics, analytical evaluation, damping capacity, viscous damper