计算核电厂楼层反应谱的直接法及其对比分析

A direct method for computation of floor response spectrum of a nuclear power plant

核电厂的楼层反应谱分析是核电厂房主结构和设备子系统抗震设计的主要依据。楼层谱计算方法可分为2种类型,一种是通过地震动反应谱输入直接得到楼层谱的计算方法,简称直接法;另一种是通过地震波输入的时程分析计算方法,简称时程法,文中主要研究前者。首先简要评述了几种具代表性的直接法,例如B iggs方法、Kapur方法、S ingh方法等,并对它们的优缺点进行了分析。然后总结了我们的工程经验,并在B iggs和Kapur方法的基础上,提出一种修正模态法,既考虑了结构-地基动力相互作用的影响,又计算简便易行,也可获得比较满意的精确度。

Analysis of the floor spectrum is the main basis for seismic design of structures and equipments in nuclear power plants（NPP）.There＇re generally two groups of methods for the computation of floor spectrum.The first group includes the so-called direct methods,where the floor spectrum is calculated directly from response spectrum of input ground motion.While the second group includes time-history analysis methods,transient analysis is characterized with time-history input as excitation.Focusing on the first group,comments on several direct methods including the ones proposed by Biggs,Kapur and Singh have been made.Based on the work of Biggs and Kapur,a revised modal method is presented.Dynamic soil-structure interaction effect is taken into consideration in the modal method.The computation of the revised modal method can be easily taken out and the result obtained is highly accurate.