近断层地震动下大型立式隔震储罐的地震响应分析

摘要

以Ⅲ类场地的15万m3立式圆柱形浮顶储罐为例,在储罐底部安装滚动隔震装置,输入Kobe地震波、汶川地震波和集集地震的2条地震波共4条近断层地震波,采用时程分析中的Wilson-θ法,通过对比分析计算储罐在传统抗震和隔震时的基底剪力、基底弯矩和晃动波高,研究滚动隔震储罐在近断层地震动作用下减震效果;通过设置不同的隔震层阻尼比来研究隔震层在近断层地震动作用下的位移.结果表明:基底滚动隔震装置可以有效降低储罐的基底剪力和基底弯矩,但对晃动波高的减震效果不太理想;隔震层上下层之间的层间位移差异较大,应采取综合措施,防止滚动隔震装置失效.%Taking the vertical cylindrical floating roof tank of 150000 cubic meters in class Ⅲ site as the example, a rolling isolation device is installed at the bottom of the tank.Four near-fault seismic waves of Kobe seismic wave, Wenchuan earthquake and two waves of Chi-Chi earthquake are inputted.Using the Wilson-θ method of time-history analysis, the seismic isolation effect of the rolling isolation tanks under the near-fault ground motion is studied via comparing the base shear force, the base moment and the sloshing height of the tank during the traditional seismic and seismic isolation.By setting different isolation damping ratio, the displacement of isolation layer in near-fault ground motion is analyzed.The results show that the base rolling isolation device can reduce the base shear and the base moment effectively, but the vibration damping effect of sloshing height is not ideal.The interlayer displacement between the upper and lower layers of the isolation layer is relatively larger, and the comprehensive measures should be taken to prevent the failure of the rolling isolation device.