Estimation of vibration property of Japanese wooden houses using subspace identification method

The purpose of this paper is to estimate the vibration properties such as the natural period and the damping ratio of Japanese wooden houses subjected to strong ground motions. A subspace identification method is used to identify the vibration property from short-time acceleration data, and the variation of the vibration property during the earthquake ground motion is estimated. First, the validity of the proposed method is investigated through a numerical study. Then, the method is applied to the result of the three dimensional shake table test on a full-scale two-story wooden house. It is shown that the subspace identification method is effective to estimate the variation of the vibration property of wooden buildings subjected to strong ground motions.