大型立式储罐在地震作用下储液晃动问题计算

大型立式储罐受地震作用的储液晃动波高是储罐抗震设计的重要指标,该指标的设计是否合理关系到储罐在地震作用下的安全性能。近断层地震动常包含速度大脉冲和丰富长周期波形,易激发长周期特性的大型立式储罐产生大幅晃动,对储罐本身和周围环境构成重大威胁。因此,为研究近断层地震动作用下立式储罐的晃动响应,通过振动台试验、有限元仿真和各国储罐规范对波高设防合理性问题的研究,试验表明,立式储罐在近断层地震动或长周期地震动作用下,晃动波高较大,且晃动波高与输入地震动峰值加速度大致呈线性关系,对模型罐进行数值仿真,通过仿真波高和试验波高的数据拟合,两者可互相验证,得出利用有限元软件ADINA进行大型立式储罐的晃动模拟是可行的;对10 000m3立式储罐做大量近断层地震动作用下的晃动仿真,利用地震动卓越周期或脉冲周期作为频谱参数表征波高都有一定的合理性,且近断层地震动激励波高明显大于在相似参数下各国储罐规范的设计波高,因此,各国立式储罐在波高设计时,有必要考虑近断层地震动对波高的不利影响。

Calculation for Sloshing of Liquid Stored in Large Vertical Storage Tanks under Earthquake

The problem of sloshing wave height of the liquid stored in large vertical storage tanks under seismic action is an important indicator for seismic design of storage tanks. Whether the design of this indicator is reasonable or not is directly related to the safety performance of storage tanks under earthquake action. Near-fault ground motions often involve large velocity pulses and rich long-period waveforms. Large vertical tanks which are prone to long-period characteristics can produce large sloshing,posing a major threat to the tank itself and its surrounding environment. Therefore,in order to study the sloshing response of vertical storage tanks under the action of near-fault ground motion,the vibration table test and finite element simulation were carried out and the rationality of the wave height fortification of storage tanks in the specifications of various countries was studied: the tests show that the vertical storage tank has a larger sloshing wave height under the action of near-fault ground motion or long-period ground motion,and the sloshing wave height shows a roughly linear relationship with the peak acceleration of the input ground motion. The model tank was numerically simulated and fitted by the data of the simulated wave height and the test wave height,they can be mutually verified. It was concluded that it is feasible to use the finite element software ADINA to simulate the sloshing of large vertical storage tanks;for a 10,000 m3 vertical storage tank,and it is reasonable to carry out a large number of sloshing simulations under the action of near-fault ground motion,and to use the excellent period or pulse period of ground motion as a spectral parameter to characterize the wave height,yet,the excitation wave height of the near-fault ground motion is obviously larger than the design wave height in the tank specifications of different countries under similar parameters. Therefore,it is necessary for various countries to take into account the adverse effects of near-fault ground motion on wave height when conducting wave height design of vertical storage tanks.