脉冲型地震动的潜在破坏能分析

Potential damage energy analysis for pulse-like ground motions

为研究预估脉冲型地震动破坏性的方法,选取Northridge地震的3条脉冲型和3条非脉冲型地震记录(峰值加速度统一调整到200gal),对比了它们的V2时-频反应谱(V2TFRS)。根据V2TFRS定义"累计动能曲线",然后结合结构振型质量参与系数,提出了地震动"潜在破坏能(PDE)"的概念。通过PDE定量地预测所选地震记录对一12层RC框架结构的潜在破坏性,并通过弹塑性时程分析结果进行了验证。结果表明,V2时-频反应谱(V2TFRS)和累计动能曲线均可用来研究脉冲型地震动的动力特性。潜在破坏能(PDE)将所选地震动特性与所分析的结构特性结合起来,有效地反应地震动的工程特性,能够定量地预测地震动潜在破坏性大小。

In order to study the method of predicting the destructiveness of pulse-like ground motions,three records of pulse-like ground motions and another three records of non-pulse-like ground motions( with the peak acceleration adjusted to 200gal) from Northridge earthquake were selected for the comparison of their V2 Time-Frequency Response Spectrum( V2 TFRS). Based on the V2 TFRS,the concept of accumulative kinetic energy curve was defined. By incorporating with the modal participating mass ratio,the concept of potential damage energy( PDE) was put forward.The potential destructiveness from the selected ground motions to a 12-storey RC frame structure was quantitatively predicted based on the PDE,and furthermore,the predictions were verified by the elasto-plastic time-history analysis.The results show that both V2 TFRS and the accumulative kinetic energy curves can be used to study the dynamic characteristics of pulse-like ground motions. By combining the characteristics of selected ground motions and the characteristics of analyzed structure,PDE can effectively reflect the engineering characteristics of seismic ground motions and quantitatively predict the degree of potential destructiveness from the seismic ground motions.