从集集地震看建筑物震害与地震动参数的关系

Study on relationship between building damage and ground motion parameters from Chi-Chi Earthquake

本文根据9.21台湾集集大地震中南投县、台中县、台北县和苗栗县的建筑物震害调查资料确定出这4个主要受害地区的平均震害指数,然后又计算出这4个地区的地震动峰值加速度、峰值速度、峰值谱加速度、峰值谱速度、峰值谱位移的平均值。将这些均值分别与平均震害指数进行基于最小二乘法的线性回归,发现峰值速度和震害指数有非常好的相关性,相关系数接近1.0,而峰值加速度与震害指数相关性只有0.8,这说明地震动峰值速度能够体现地震动对脆性结构的破坏势,与以往将不同次地震的记录和资料混淆在一起研究而获得峰值加速度与震害有很好相关性形成了对比。

The authors calculated the mean damage indexes of Nantou county,Taichong county,Taipei county and Miaoli county based on the building damage of these regions resulting from the Chi-Chi Earthquake. Then the authors calculated the average value of PGA,PGV ,PSA,PSV ,PSD in these four regions and conducted the linear regression between the average value and the mean damage index based on the least-square method. The result shows that PGV has very good correlation with the mean damage index and the corresponding correlation coefficient is near 1.0 while the correlation coefficient between PGA and the mean damage index is ouly 0.8. This indicates that PGV can reflect the damage potential of ground motion better. This result may be comparable to the historical results, which were obtained by mixing up the ground motion records and damage documents of different earthquakes and showed that PGA has good correlation with buihting damage.