921台湾集集地震灾害最严重地区的烈度评定

Preliminary assessment of seismic intensity for main regions of heavy disaster in Chi-Chi Earthquake

根据9.21台湾集集大地震过后南投县、台中县、台北县和苗栗县这四个主要受害地区的建筑物震害,参考不同的评定烈度标准综合确定出这四个地区的地震烈度,然后又计算出四地区的地震动峰值加速度、峰值速度、峰值谱加速度、峰值谱速度以及峰值谱位移的平均值。将这些均值分别与地震烈度进行基于最小二乘法的线性回归,发现这些地震动参数均值除峰值谱位移外都和烈度有很好的相关性,相关系数均在0.95以上,这说明研究评定的这四个地区的地震烈度是正确合理的,可以加以推广并应用于其它地震研究工作中。同时由于地震烈度是描述地震破坏后果的物理概念,地震动参数和烈度间的良好相关性也说明地震动参数和建筑物震害有很大的关联性,能够体现对结构的潜在破坏势。

The seismic intensities of main regions of heavy disaster （ Nantou county,Taichong county,Taipei county and Miaoli county） in the 9.21 Chi-Chi Earthquake are assessed by the different criterion. Then the average values of PGA,PGV,PSA、PSV,PSD in these four regions are calculated and the linear regression between the average values and the seismic intensites is carried out based on the least-square method. The results are shown that all these ground motion parameters except PSD have good correlation with the intensities and the corresponding correlation coetticiens are all above 0.9. This indicates that the seismic intensity assessed by the method above is right and valid. Hence the results can be generalized and applied to related research of other strong earthquakes. In addition, because the seismic intensity is a physical definition describing the earthquake damage, the good correlation between the ground motion parameters and the intensifies indicates that ground motion parameters have very good relationship with damage to buildings in strong earthguakes. So the ground motion parameters （PGA,PGV, PSA and PSV） can indicate the damage potential of structures.