【作者】 郭达文；

【导师】 杨笑梅；

【作者基本信息】 广东工业大学 ， 工程力学， 2012， 硕士

【摘要】 我国部分在建或者拟建核电厂选址于非均匀场地,对这类重大结构的地震反应特征分析需合理考虑土-结构相互作用(简称SSI)的影响。核电厂厂址复杂性的出现以及人们对核电厂安全要求日益提高使得传统的计算方法和计算软件(如SASSI、FLUSH、 CLASSI等)在用于这类工程问题时遇到一定困难。不合理或过于简化的计算模型均可能给核岛结构及其设备造成不确定的安全隐患。本文选取处于常见复杂场地条件下的某类压水堆核电厂SSI体系为研究对象,旨在提出优于传统分析的计算模型,探讨核电厂结构在强震作用下的动力特性和远场反应特征,得到了一些有意义的结论。具体工作如下述：1.在深入分析、总结已有的SSI体系分析方法及研究成果基础上,采用时域显式有限元法结合多次透射边界的思想,提出了适用于复杂场地条件下的核电厂SSI体系地震反应分析的时域显式分析过程。2.基于本文方法,计算了核电厂SSI体系的自振特性,并与未考虑SSI作用的自振特性进行比较,探讨了不同地基条件下核电厂自振特性的变化。3.通过对现有大震记录特征比较分析,归纳地震记录空间变化特征及频谱特性,并从汶川及福岛地震中各选出5条用有代表性的露头基岩强震记录作为核电厂SSI体系的地震输入时程。基于本文方法,计算在不同地基条件下核电厂SSI体系基底等效地震输入、和楼层反应,并与未考虑SSI作用的复杂场地模型及未考虑SSI作用的均匀场地模型结果进行比较,分析其地震动输入,反应谱及楼板谱的变化特征和规律。指出复杂场地条件下,对核电结构进行强震反应分析时考虑SSI影响是非常必要的。4.对本文研究工作进行总结,在此基础上对未来工作提出展望。更多还原

【Abstract】 Many nuclear power plants (NPP) in China are being or plan to be built recently on a non-uniform field condition. The effect of Soil Structure Interaction (SSI) on seismic response analysis is needed to be considered to the NPP on a complex site condition. However, the analysis of this kind of nuclear SSI system based on conversional method and software popular in the past (such as SASSI, FLUSH, CLASSI, etc) often suffer from some computational difficulties because of the complexity of the site and the increasing requirements of NPP safety. The unreasonable or simplified analysis models may bring about uncertain security risks on nuclear island and equipments. This thesis aims to develop computational models that are more efficient and accurate than the conversional ones. Moreover, in accordance with the presented models, the dynamic characteristics and strong seismic response characteristics of the NPP are discussed in detail. Some significant results are given. The studies done in the paper include:1. The existing methods and models for dynamic SSI system are summarized. Moreover, Base on the existing lumped-mass explicit finite element method (FEM) with a local transmitting boundary condition, an explicit procedure in the time domain is developed for the analysis of three-dimensional dynamic SSI analysis.2. Based on the proposed computational procedure, the nature frequencies are given in accordance with the NPP SSI systems on various of site conditions. Comparing with the results without SSI effect, the characteristics of frequency change are discussed in detail for these NPP SSI systems.3. According to a large number of strong ground motion records, the characteristics of strong ground motion records are summarized with distance and frequency spectrum.5large magnitude of far field outcrop bedrock strong ground motion records respectively from Wenchuan and Fukushima are used as earthquake incident wave of NPP SSI system. Based on the proposed procedure, the equivalent seismic inputs and response specta are computated from various of NPP SSI models. Comparing with the corresponding results given by uniform site conditions and complex site conditions without the SSI effect, the changes of the seismic input, response spectrum and floor spectrum characteristics are discussed and summarized. The results show that it is neccessory for NPP system to consider the effects of soil-structure interaction on the strong seismic even in far field.更多还原