钢制安全壳的抗震可靠性计算研究

Study on the Seismic Reliability of Steel Containment

随着我国工业、民生对电能日益增高的要求,核电站也朝着大功率方向发展,而体积扩大后的钢制安全壳能否抵御强震作用,是我们所关注的焦点。目前,安全壳的抗震分析多基于确定论方法,而实际工程中,结构的尺寸、材料参数等往往具有随机性,并且地震载荷本身就具有复杂的统计性变化。因此,传统的确定论方法难以验证结构的安全性。文章以大功率钢制安全壳为工程背景,基于随机地震动模型建立了有不同发生保证概率的随机地震反应谱,根据我国现行的抗震规范确定了随机地震动模型参数。分别从基于确定性地震强度和基于确定性发生保证概率两方面进行抗震可靠性分析,最终通过蒙特卡洛模拟得到了安全壳的敏感性参数。研究成果可为今后钢制安全壳的抗震可靠性设计提供参考与借鉴。

In recent years, more and more high-power nuclear power plants were constructed in China to meet the increasing needs of electricity. The volume of the containments in nuclear power plants increases with the increase of the power level. Therefore, accessing the ability of steel containment to resist strong earthquakes has attracted more attention recently. So far, the most seismic analysis methods are based on deterministic methods. In fact, the parameters in the engineering projects, such as geometry, material and load value, are usually uncertain. The seismic loads aslo have a complex statistical change, which is one of the natural properties of seismic wave. Therefore, the traditional deterministic methods are difficult to verify the safety of the structure. In this article, the seismic reliability of the large steel containment was studied. The random seismic response spectrum under different probabilities was established according to the stationary stochastic model. The parameters of the stationary stochastic model were obtained from Chinese seismic code. Two methods of seismic reliability analysis were considered. One is under deterministic seismic intensity, the other is under the certainty probabilities. Finally, the sensitivity parameters were calculated based on the Monte Carlo method. This article will provide some references for the seismic reliability design of the steel containment.