Structural investigation and seismic performance evaluation of traditional wooden houses in Gojoshinmachi in Nara prefecture in Japan

Gojoshinmachi in Nara, which was designated as Important Preservation District for Groups of Historic Buildings (IPDGHB) in 2010, has a large number of traditional wooden houses. In this area, damage resulting from the next Nankai earthquake is concerned. Therefore, to understand structural characteristics of the houses in Gojoshinmachi, first, we conduct structural investigation of several houses and evaluate their seismic performance. Next, we compare structural characteristics among traditional wooden houses in other 6 regions. The following can be stated. a) The width of frontage of the houses in Gojoshinmachi is large. b) Yield base shear coefficients C_y in both weak axis and strong axis are small. Moreover, C_y of some houses in weak axis falls below 0.1. c) The average of C_y is smaller than other regions. This is because there is a tendency that the width of frontage of house increases, the value of the yield base shear per unit first floor area decreases.