[论文解读] Dynamic Structure-Soil-Structure Interaction for Nuclear Power Plants

Konstantinos Kanellopoulos, Peter Rangelow+3 more|arXiv (Cornell University)|Oct 16, 2023

Structural Response to Dynamic Loads被引用 1

一句话总结

本研究利用Real-ESSI模拟器中的高保真3D有限元模型，研究了核电站中的动态结构-土壤-结构相互作用（SSSI），发现非线性土壤和界面行为可将有害的旋转耦合转化为有益的反向水平相互作用，使靠近辅助厂房共振频率处关键反应堆部件的谱加速度降低高达55%。

ABSTRACT

The paper explores the linear and nonlinear dynamic interaction between the reactor and the auxiliary buildings of a Nuclear Power Plant, aiming to evaluate the effect of the auxiliary building on the seismic response of crucial components inside the reactor building. Based on realistic geometrical assumptions, high-fidelity 3D finite element (FE) models of increasing sophistication are created in the Real-ESSI Simulator. Starting with elastic soil conditions and assuming tied soil-foundation interfaces, it is shown that the rocking vibration mode of the soil-reactor building system is amplified by the presence of the auxiliary building through a detrimental out-of-phase rotational interaction mechanism. Adding nonlinear interfaces, which allow for soil foundation detachment during seismic shaking, introduces higher excitation frequencies (above 10 Hz) in the foundation of the reactor building, leading to amplification effects in the resonant vibration response of the biological shield wall inside the reactor building. A small amount of sliding at the soil-foundation interface of the auxiliary building slightly decreases its response, thus reducing its aforementioned negative effects on the reactor building. When soil nonlinearity is accounted for, the rocking vibration mode of the soil-reactor building system almost vanishes, thanks to the strongly nonlinear response of the underlying soil. This leads to a beneficial out-of-phase horizontal interaction mechanism between the two buildings, reducing the spectral accelerations at critical points inside the reactor building by up to 55% for frequencies close to the resonant one of the auxiliary building. This implies that the neighboring buildings could offer mutual seismic protection to each other, in a similar way to the recently emerged seismic resonant metamaterials, provided that they are properly tuned during the design phase.

研究动机与目标

• 通过动态SSSI评估辅助厂房对反应堆厂房地震响应的影响。
• 评估土壤和界面非线性对核电站中SSSI机理的影响。
• 研究相邻结构是否能提供相互地震保护，类似于地震共振超材料。
• 开发并应用具有真实土壤剖面和非线性界面的高保真3D有限元模型。

提出的方法

• 利用Real-ESSI模拟器开发了反应堆厂房和辅助厂房的高保真3D有限元模型。
• 采用域缩减法（DRM）将SH波加速度时程注入土壤域。
• 采用循环弹塑性本构模型模拟黏土的弹性与非线性土壤行为。
• 模拟了粘结和非线性土-基础界面，包括脱离和有限滑移。
• 逐步分析更复杂的模型：首先为弹性土壤与粘结界面，然后为非线性界面，最后为非线性土壤与非线性界面。
• 在一系列频率范围内评估反应堆厂房关键点的谱加速度。

实验结果

研究问题

• RQ1 辅助厂房的存在如何通过SSSI影响反应堆厂房的地震响应？
• RQ2 土壤和界面非线性在改变相邻核电厂之间动力相互作用机制中起什么作用？
• RQ3 相邻结构之间的SSSI是否能产生有益的地震防护效果，类似于共振超材料？
• RQ4 非线性界面如何影响反应堆厂房基础处高频激励的发展？
• RQ5 相邻厂房的动力特性在多大程度上可被调节以降低关键部件的地震需求？

主要发现

• 当土壤和界面为弹性且粘结时，由于有害的反向旋转相互作用机制，辅助厂房的存在会放大反应堆厂房的谱加速度。
• 非线性界面在反应堆厂房基础处引入了高频激励（>10 Hz），增加了生物屏蔽墙和反应堆压力容器的共振响应。
• 辅助厂房界面处的有限滑移略微降低了其响应，从而减轻了对反应堆厂房的负面影响。
• 非线性土壤行为抑制了反应堆厂房的摇摆模态，使相互作用机制转变为有益的反向水平模式。
• 在接近辅助厂房共振频率的频率下，关键反应堆部件（如圆柱形墙体和反应堆压力容器）的谱加速度因这种有利的动力相互作用而降低高达55%。
• 结果表明，当适当调谐时，SSSI可提供相互地震保护，提示在地震区设计具有韧性的建筑群或“超材料城市”具有潜在可能。