核电结构设计中参数不确定性对楼层谱计算影响分析

核电厂房的楼层反应谱是核电结构和设备抗震设计的依据．采用通常的确定性的方法计算只能选择可能性比较大，但又相对比较保守的荷载和结构参数进行分析，对计算结果反映实际的程度很难作出可靠的判断．在动力相互作用分析的基础上，针对核电结构设计中的参数不确定性问题，采用基于蒙特卡罗模拟的概率统计法进行楼层反应谱的分析．这种方法可以适应性能参数概率密度函数的各种不规则变化，在概率统计基础上获取不同置信率的响应结果．数值算例表明，该模型合理，计算结果可以对传统的确定性分析结果进行置信率的定量判断，进而对传统确定性方法设计的核电结构安全性有更深入的了解．

Analyses of effect of parameter uncertainty in NPP design on computation of floor response spectra

Floor response spectrum is the basis for design of structures and equipments in a nuclear power plant (NPP). In current routine of NPP design, deterministic methods are generally employed for computation of floor spectra, in which a proper estimate of loadings and structural parameters, with a good possibility yet conservative, has to be chosen, yielding results difficult to reflect the complicated real situation. To solve this problem, probabilistic and statistical method based on Monte-Carlo simulation is employed in the analyses of floor response spectra of this complicated stochastic system on the dynamic interaction analyses. This procedure can perfectly consider the irregular probabilistic density functions of physical parameters, and obtain floor spectra of different guarantee ratios. Numerical examples show that the numerical results can be used to evaluate the guarantee ratio of results obtained from deterministic analyses, providing better understanding of the safety of NPP designed with conventional deterministic method.