序列型强主余震作用下核岛结构灾变机理与三维隔震控制

Nuclear power has become an important part of China’s energy structure, nuclear engineering construction is being recovering roundly and developing rapidly, but its seismic safety is facing new challenges as frequent strong earthquake records in recent years. The project focus on disaster mechanism analysis and three-dimensional seismic isolation control technology of nuclear island structure under main shock-aftershock sequence-type ground motions, Firstly, shaking table test model and elastic-plastic model that consider damage accumulation effect of nuclear island structure are built, which are used to study energy consumption, plastic deformation characteristics and damage failure processes of nuclear island structure under strong shock-aftershock ground motions. Strong shock-aftershock ground motions and it’s duration influence on structure catastrophe evolution and cumulative damage accelerating effect that are discussed, disaster mechanism of nuclear island structure are revealed. Secondly, new kinds of three-dimensional seismic isolation device which can anti overturn are developed, Then, the yield stiffness before and after ultimate deformation, yield force, equivalent stiffness, equivalent damping ratio and other parameters of mechanical property are analyzed, the control effect of new kinds of three-dimensional seismic isolation device to structure dynamic catastrophe evolution is researched and the optimum range of isolation layer parameter is received. Finally, the analysis and design method of nuclear island structure and its isolation system are found. The project research contributes to cover the shortage of seismic behaviors of nuclear island structure under strong shock-aftershock ground motions, which can provide theoretical reference and technical support for safe and reliable design of nuclear island structure.

核能已成为我国能源结构的重要组成部分，核电工程建设全面复苏、发展迅猛，但近年来频发的强主余震记录，为其抗震安全性带来了新的挑战。本项目聚焦核岛结构在序列型强主余震作用下的灾变机理分析与三维隔震控制技术，首先建立核岛结构模拟地震振动台试验模型和考虑塑性损伤累积效应的弹塑性模型，研究强主余震作用下核岛结构的能量耗散、塑性变形特征和损伤破坏过程，探讨强余震及其持时对结构动力灾变演化的影响和产生的损伤累积加速效应，揭示核岛结构灾变机理；其次研发具有抗倾覆能力的新型三维隔震装置，对其开展极限变形前后屈服后刚度、屈服力、等效刚度及等效阻尼比等参数的力学性能对比分析，研究新型三维隔震装置对核岛结构动力灾变的控制效果，优化给出隔震层参数最佳取值范围；最后建立核岛结构三维隔震体系的分析与设计方法。项目研究有助于弥补强主余震下核岛结构抗震性能研究的不足，可为安全可靠的核岛结构设计提供理论参考和技术支撑。

序列型强主余震作用下的核岛结构灾变机理分析、性能状态、灾变控制效果及隔震装置的性能状态是核岛结构中尚需大力关注的重点问题。本项目围绕上述问题展开研究，建立了考虑塑性损伤累积效应的弹塑性模型的核岛结构，构造了适用于核岛结构抗震性能研究的序列型地震动，研究了强主余震作用下核岛结构的地震响应、能量耗散、和损伤破坏过程，探讨了核岛结构在主震阶段和各余震阶段的地震响应和损伤发展情况，对比分析了两种主余震构造方法在各个工况的余震时段屏蔽厂房顶点的塑性位移增量、各余震阶段屏蔽厂房的混凝土裂缝发展云图、混凝土受拉损伤云图、混凝土受压损伤云图、结构自振周期的变化情况，揭示了核岛结构灾变机理，引入基础隔震技术对核岛结构进行震动控制研究，进一步研究了隔震周期、刚度比、屈重比等隔震层参数对核岛结构动力响应的影响。研究有助于弥补强主余震下核岛结构抗震性能研究的不足，为完善安全可靠的核岛结构设计提供理论参考和技术支撑。