脉冲型地震动对隔震框架结构地震位移反应的影响分析

Influence of pulse-like ground motions on the seismic displacement responses of isolated frame structure

脉冲型地震动有着不同于一般地震动的特征。采用Seismo Struct建立某12层钢筋混凝土框架隔震结构模型,以集集地震中36条脉冲型地震动作为输入对其进行动力时程分析,分析了隔震结构的支座位移、楼层最大位移、层间位移等位移反应,研究位移反应与脉冲型地震动参数(峰值加速度、峰值速度、峰值速度与峰值加速度的比值、Arias强度、Housner强度、速度脉冲周期与自振周期的比值)的相关性。结果表明,峰值速度PGV和强度类指标HI与隔震结构位移反应的相关程度显著,建议增加PGV为隔震框架结构抗震设计选用地震动提供依据。

The pulse-like ground motion is different from the general ones. Seismo Struct was used to establish a 12-storey reinforced concrete frame isolation structure model. The dynamic time-history analysis was carried out with 36 pulse-like ground motions as input in the Chi_Chi earthquake. The displacement responses of the isolation structure,such as bearing displacement,maximum story displacement and inter-story displacement were analyzed. The correlation between displacement responses and parameters of pulse-like ground motion,such as peak acceleration,peak velocity,the ratio of peak velocity and peak acceleration,Arias intensity,Housner intensity,the ratio of velocity pulse period and natural vibration period. The results show that the peak velocity PGV and strength index HI are significantly correlated with the displacement response of isolated structures. It is suggested that PGV be added to provide the basis for seismic design of isolated frame structures.