立式储罐基底隔震的基本理论

Theoretical study on seismic isolation of storage tanks

摘要:

鉴于目前储罐基底的隔震研究大都是在Haroun模型的基础上进行的.本文以储罐基底隔震为基础,从储罐的晃动、刚性运动、液固耦联弹性运动出发,根据储罐结构所满足的速度势和边界条件,选择合理的势函数,研究储罐动水压力、波高、基底剪力和弯矩的动响应理论表达.利用相同激励下原型罐和等效力学模型罐基底剪力和弯矩等效原则,求出储罐分析力学模型的等效质量及相对质心高度,建立了隔震三质点控制体系简化分析的力学模型,给出了储罐抗震设计参数波高、基底剪力和弯矩简化分析表达.由Harmilton原理出发,考虑晃动和罐——液耦联振动周期相差较大,将两者作为不耦联运动,建立了隔震体系的运动方程.并对2×104m3和15×104m3储罐隔震和非隔震地震响应进行了时程分析研究,结果表明,基底隔震体系起到了很好的隔震效应.

Abstract:

Based on the seismic isolation study of the storage tanks,starting with sloshing,rigid motion and fluid-structure coupling motion of the tanks,the dynamic response theory of hydrodynamic pressure,sloshing wave,base shear and overturning moment of the storage tanks was studied.Rational potential function was selected according to the velocity potential and boundary conditions that the structure of storage tanks satisfied.The equivalent mass and the relative height of mass center were given by using the same base shear and overturning moment of the liquid tank system and equivalent mechanical model when subjected to the same ground motion,and a three centralized particles mechanics analysis model was established.The simplified expressions of sloshing wave,base shear and overturning moment were given as well.The motion equation of the seismic system was established according to Harmilton principle.The earthquake responses of 2 × 104 m3and 15 × 104 m3 isolated and non-isolated tanks were analyzed by adopting the time history method.The numerical result shows that the base isolation seismic system exhibits good performance of seismic isolation.