【摘要】 对LRB(Lead Rubber Bearing)基础隔震结构在近断层脉冲型地震作用下的动力响应进行了系统参数研究。考虑到近断层脉冲型地震动记录数量的有限性,为了参数研究的方便,提出了人工合成近断层脉冲型地震动的方法,即以实际的常规地震波(即远场地震)为底波,在此基础上叠加上等效脉冲模型来模拟近断层脉冲型地震;以此为输入,系统研究比较了在近断层脉冲型地震和常规地震作用下,LRB基础隔震结构的动力反应特性、不同的近断层脉冲型类型以及近断层脉冲型地震动参数和LRB隔震系统力学性能对上部结构最大绝对加速度和隔震层最大位移的影响。研究表明:LRB基础隔震结构在近断层脉冲型地震作用下,上部结构最大绝对加速度和隔震层最大位移与常规地震作用下相比,均有较大增加,隔震范围有一定减小;近断层地震动的脉冲类型,以及脉冲周期对LRB基础隔震结构的动力反应有很大的影响。更多还原

【Abstract】 In this paper,parametric study on the dynamic response of LRB(Lead Rubber Bearing) base-isolated structure under near-fault pulse-like ground motions is investigated. Due to the limited number of real near-fault pulse-like records,for the convenience of parametric study,the artificial generated near-fault pulse-like ground motions are simulated by combining the real far-field ground motion with simple equivalent pulses that reflect the near-fault features. Using these artificial generated near-fault pulse-like ground motions,the different dynamic characters of LRB base-isolated structure under near-fault pulse-like and far-field ground motions are studied. Moreover,effect of different pulse types,near-fault ground motion parameters and dynamic properties of LRB isolation system on the maximum absolute acceleration of superstructure and maximum displacement of isolation level is discussed. It can be indicated from the comprehensive study that maximum absolute acceleration of superstructure and maximum displacement of isolation level of LRB base-isolated structures subjected to near-fault pulse-like ground motions are much greater than those under far-field ground motions,effective range of base isolation is narrowed; pulse type and pulse period have significant influence on the dynamic response of LRB base-isolated structures.更多还原