立式浮顶储罐基础隔震地震响应研究

Study on the seismic responses of vertical floating roof storage tanks with the base isolation

为研究浮顶储罐基础隔震地震响应问题,将浮顶假定为均质刚性圆板,波高振动形式受浮顶约束假设为沿半径线性分布.由速度势理论出发,建立液体运动势函数、基底剪力、倾覆力矩表达,由板振动理论建立浮顶运动方程,由能量原理建立罐体运动控制方程.采用时程分析方法研究了浮顶储罐基础隔震的地震响应,数值结果表明:隔震基频宜取2～3rad/s、隔震阻尼比宜取0.1,Ⅰ类、Ⅱ类场地减震率效果好于Ⅲ类、Ⅳ类场地,场地不同对波高的影响不同,高径比对隔震浮顶储罐的地震响应影响不大.

To study the seismic response of floating roof storage tank with the base isolation,the floating roof is assumed as a homogeneous rigid circular plate,the vibration form of wave height is assumed as linear distribu-tion along the radius.By the velocity potential theory,the velocity potential function of the liquid movement and the expression of base shear and overturning moment are established and by the plate vibration theory and energy principle,the motion equation for the floating roof and the motion equation for the tank system are pres-ented,respectively.With the time history analysis,the seismic responses for the isolated floating roof storage tanks are studied.The numerical results show that the fundamental frequency of isolation is applicable to be 2-3 rad/s,while the damping ratio of isolation is 0.1.The damping rates ofⅠ,Ⅱsite are better than those of Ⅲ,Ⅳsite.The effects of different sites on wave height are different,and the ratio of height to diameter has little effect on the seismic response of the isolated floating roof storage tanks.