近场地震速度脉冲效应及模拟模型的研究

从近场地震速度脉冲的形成机理分析入手 ,对近场地震动的时程曲线和反应谱进行探讨 ,说明了具有前方向性速度脉冲效应的幅值要大的多 ,对反应谱的长周期段影响显著 ,使反应谱变胖 ,引起谱峰值向长周期处漂移 ,蕴含了巨大的地震能量 ,因此 ,对结构抗震提出了更高的要求。在以上研究的基础上 ,对典型的简化脉冲模拟模型参数进行讨论 ,提出了更为合理的参数取值 ,最后 ,从时程曲线、反应谱和结构地震反应 3个方面 ,对模拟脉冲和实际记录的差异进行对比 ,验证了推荐参数的合理性。

Study on Velocity Pulse Effect and its Simulated Model for Near-Fault Ground Motions

The formation mechanism, time history and response spectrum of velocity pulse of near-fault ground motions are studied in order to reflect that the velocity pulse effect concluding in the forward directive records is remarkable. The effect of forward directivity on the response spectrum is to increase the spectra value in long period, which makes spectrum being richer and the spectra peak shift to long period. The tremendous energy contained in velocity pulse has put new question in the seismic design of the structure. On such a basis, the parameters of the typical velocity pulse model are discussed and modified. The rationality of the recommended parameters for the velocity pulse model is verified by comparing the history-time trace, the response spectrum and the structural seismic response of records with those of the simulated pulse.