A STUDY ON DYNAMIC CHARACTERISTICS OF TRADITIONAL WOODEN BUILDING

由于传统木结构建筑一般都是珍贵的文化财产，我们通常需要运用无损检测的理念来了解其动态特性。微震测量是利用高灵敏度传感器测量建筑物在1/ 1000mm ~ 1/ 100mm范围内的连续微振动的方法。这种方法的适用性令人满意，因为它不会损坏或摆动建筑物，并且在测量过程中很容易将传感器放置在梁或地板上。为明确日本传统木结构建筑的动力特性，对9栋建筑进行了微震测量。通过对微震记录的FFT分析，得到了各建筑物的固有频率、阻尼因子和振型。其次，在考虑柱摇阻力和粘土墙影响的情况下，估计了其中五座建筑物的侧向荷载-位移关系。利用初始刚度计算值和质量估计值，得到了平行模态振动的固有频率值。最后，将固有频率计算值与微震观测值进行了比较。比较表明，计算值与观测值之间有充分的相关性，尽管计算值的绝对值低于观测值。因此，微震测量似乎可以作为一种无损诊断结构抗震性能的方法。日本传统木结构建筑。

As the traditional timber buildinds are generally valuable cultural properties, we usually have to employ the non destructive examination philosophy to understand their dynamic characteristics. Micro tremor measurement is a method of measuring the continuous micro vibration of the buildings whose amplitude is from 1/1000 mm to 1/100 mm with high sensitive sensors. This method is satisfactorily applicable as it is not to damage or swing the buildings and it is easy to place the sensors on the beam or floor during the measurement.To clarify the dynamic characteristics of Japanese traditional timber buildings, micro tremor measurement were performed on nine buildings. By FFT analysis on the record of micro tremor, we obtained natural frequencies , damping factors and vibration modes of each building. Next, the lateral load- displacement relationships of five buildings among them were estimated, considering column rocking resistance and the effect of clay walls. And the values of natural frequency for parallel mode vibration were obtained using calculated values of initial stiffness and the estimated values of mass. Finally , the calculated values of natural frequency were compared with those observed in micro tremor measurements. The comparison showed an adequate correlation between the calculated values and the observed values of natural frequency, though the absolute values by calculation were lower than those observed. Therefore, micro tremor measurement seems to be applicable as one method in non-destructive diagnosis for seismic performance of.Japanese traditional timber buildings.