强震下核岛结构多级隔震的动力性态与响应控制

The damage of Fukushima Nuclear Power Plant structure was caused by the Japan's northeastern earthquake. So how to ensure the safety of nuclear power plant structure under great seismic has become a topic which should be solved urgently. Nuclear power isolation structure defect is that the relative displacement of the nuclear island will increase significantly when the earthquake strikes, can lead to fracture destruction of in and out of the nuclear utilities. Based on the uncertainty of the earthquake, the research target of this project was nuclear power plant full system safety operation including structure, piping and internal equipment. The AP1000 was carried out multilevel isolated control in this project. This program is aimed at the dynamic behavior and response control of isolation nuclear power plant structure in SL1,SL2,exceeding SL2 design standard earthquake level, through the theoretical research, dynamic model test and numerical analysis. The critical conditions of mathematics mechanical model about the multilevel isolation nuclear power plant structure from the SL1 isolation state to the SL2 isolation state and the SL2 isolation state to exceeding SL2 isolation state was proposed.The state of nonlinear dynamic behavior and fine analysis model was established to carry out multilevel isolated structures for nuclear power plants. The coupling and impact effects between internal equipment and vessel was revealed in multilevel isolation states, and the seismic response characteristics and mechanism of earthquake damage was proposed. Nuclear isolation structure multi-level isolation response control strategies was proposed. This project for enlarging application field and seismic security under the strong earthquake of nuclear power plant has important significance.

日本311地震造成了福岛第一核电厂严重核事故，引起全世界对核电安全的关注，在特大型地震作用下如何确保核电厂全系统工作安全已成为亟需解决的科学难题。核电厂结构对抗震具有严格要求，采用隔震技术后，地震发生时安全壳及内部设备的反应降低，抗震安全性提高，同时结构相对位移会显著增加，确保出入核岛的管线安全是关键环节。基于地震的不确定性，本项目以核电厂结构抗震性能为条件，以全系统包括结构、管线和内部设备的安全运营为目标，以AP1000系统为依托，开展核岛结构隔震分级控制研究。系统地开展从SL1、SL2到超SL2水准地震下核岛结构多级隔震的动力性态及响应控制研究，建立多级隔震临界条件的数学力学模型、分级隔震转换装置以及精细化分析模型；揭示多级隔震状态下的屏蔽厂房\钢安全壳\内部设备地震响应特征；提出核岛结构多级隔震的地震响应控制策略。本项目对拓宽核电厂的应用区域和在超设计地震下安全性具有重要的意义。

本项目进行了核电厂多级隔震体系的相关理论和试验等研究，具体研究内容和工作成果包括：①研发了一种新型多级隔震装置，并进行了力学性能试验研究，基于试验结果建立核岛多级隔震支座多级刚度模型。②进行了核电厂多级变刚度隔震理论研究及数值分析。建立核岛多级隔震结构的精细化分析模型。③完成核电厂核岛多级隔震结构的地震响应数值分析研究，研究不同地震峰值输入、远场、近场及频谱特性对上部结构地震响应、楼层反应谱、隔震层最大位移及竖向拉压情况的影响。④建立非平稳随机地震作用下核岛多级隔震结构的随机振动方程，对核岛多级隔震结构的非平稳随机地震响应进行分析。⑤进行了核电厂多级变阻尼隔震理论研究及数值分析。研发了一种新型变阻尼粘滞阻尼器，编制了变阻尼粘滞阻尼器减震结构的动力分析程序，进行了变阻尼减震结构的动力响应分析，提出了一种基于动力响应减震系数计算附加等效阻尼比的方法。⑥进行核电厂LRB1100/LRB1200支座基本及极限力学性能试验研究，系统研究了核电厂LRB1100/LRB1200支座的力学性能指标。⑦提出了一种适合铅芯橡胶隔震支座在大变形条件下的非线性硬化模型，采用数值分析方法研究了隔震支座在特大地震下进入硬化后核电厂结构的地震响应。⑧构建了考虑橡胶支座大变形硬化的多线性恢复力模型，并研究了不同地震峰值输入下传统双线性模型结构与大变形硬化模型结构的动力响应、弹塑性反应谱、结构塑性状态发展及结构塑性耗能情况。