考虑土-结构相互作用和岩土参数不确定性的核电厂结构地震响应分析

针对核电厂结构,在考虑土-结构相互作用(SSI)的情况下进行随机地震反应分析,探讨地基岩土参数的不确定性对反应堆厂房楼层反应谱(FRS)的影响。运用ANSYS软件模块建立核电厂(NPP)结构有限元模型,通过设置边界弹簧单元和阻尼装置来考虑SSI效应;并且通过设置具有概率意义的弹簧刚度和阻尼系数,来模拟土特性参数的不确定性。随机响应分析与确定性分析的结果对比,揭示了岩性地基条件下SSI效应对核电厂FRS的影响以及地基岩土参数不确定性对FRS的影响程度。研究表明,在岩性地基条件下,亦不应忽略SSI效应;考虑SSI效应的随机分析模型同确定性模型相比,二者的分析结果较为接近,两方法都可用于NPP的FRS敏感性分析评估之中,并可进行相互比照。

Seismic response analysis of nuclear power plant structures considering soil-structure interaction and uncertainty of soil properties

In this paper,the stochastic seismic response analysis for a nuclear power plant structure is carried out considering the soil-structure interaction,and the influence of uncertain soil properties on the floor response spectrum of a nuclear power plant structure is mainly investigated.When the finite element model of a nuclear power plant structure is built using the ANSYS software,the soil-structure interaction is considered by setting the boundary spring and damper,and uncertain soil properties are simulated by putting some stochastic parameters for stiffness of spring and damping of damper.The influence of soil-structure interaction on the floor response spectrum of a nuclear power plant structure and the sensitivity of uncertain soil properties on the floor response spectrum of a nuclear power plant structure are revealed by numerical simulation and comparison between the results of stochastic and deterministic analyses.A conclusion is drawn that the characteristics of the floor response spectrum of a nuclear power plant structure may be explored by the stochastic analysis method,which provides a reference for evaluating the parametric sensitivity of the floor response spectrum by using the probabilistic method.