【摘要】 采用Bouc-Wen模型模拟铅芯橡胶支座(LRB)非线性力学性能,建立LRB基础隔震储罐地震反应的数值模型。利用叠加原理得到人工合成近断层脉冲型地震动,从实际典型近断层地震动和人工近断层脉冲地震动输入两个角度出发,以远场地震反应为参照,系统探讨了近断层地震动作用下LRB隔震储罐地震反应特点以及近断层地震动运动特征的影响规律。研究发现,近断层地震动作用下LRB隔震储罐地震反应明显大于远场地震反应值,显著的近断层脉冲效应是隔震储罐设计不容忽视的问题。近断层地震动的PGV/PGA值是决定隔震储罐地震反应的综合指标,PGV/PGA值较大时,隔震储罐地震反应脉冲效应突出。另外,脉冲周期、脉冲参与系数以及脉冲类型也是影响LRB隔震储罐地震反应的重要因素。在脉冲参与系数越大、含有脉冲数量越多的近断层地震动作用下,隔震储罐地震反应越强烈。当脉冲周期接近储罐晃动周期时,晃动波高会出现峰值。更多还原

【Abstract】 Analytical mechanical model for lead rubber bearing(LRB) base-isolated liquid storage tank is established.The Bouc-Wen model is adopted to simulate the non-linear hysteretic characteristics of force-displacement relationship for LRB.Artificially generated near-fault ground motions(NF) are obtained on the basis of superposition principle.The seismic responses and main influence factors of LRB base-isolated storage tank under actual near-fault ground motions and artificially generated NF ground motions are investigated in comparison with the results of far-field ground motions.The result shows the seismic responses of base-isolated tank subjected to near fault ground motion is much greater than that under far-field excitation due to pulse-like effect.The effect of pulselike of NF ground motion can’t be neglected in the design of base-isolated storage tank.It is found that the PGV / PGA of NF ground motion is an important index to determine the seismic responses,which are drastic for larger PGV / PGA.The pulse period,pulse contributing factor and pulse types are the main parameters that dramatically affect the response characteristics of base-isolated tank.The seismic responses of storage tank are more fierce,if the NF ground motions have larger pulse contributing factor and large amount of puls.The seismic responses of storage tank reach their maximum when the pulse period is close to the sloshing period of tank.更多还原