考虑地基不均匀性核反应堆地震响应分析

Seismic response analysis of nuclear reactor buildings considering inhomogeneity of their foundations

核电站结构地震响应主要取决于地震动特性、地基土特性以及结构特性。本文以某核电站反应堆厂房结构为对象,研究了考虑土-结构相互作用的不均匀地基土对核反应堆地震响应的影响,包括核反应堆和地基的最大加速度、楼层最大相对位移以及楼层多阻尼反应谱。结构地震响应分析使用SUPERFLUSH/2D软件,地基模型由ANSYS建模;核反应堆采用集中质量模型。模型底部及两侧均可考虑无限体能量传递边界,底部表达波动的能量传递;两侧表达波动的逸散。研究结果揭示了地基不均匀性对核电厂反应堆楼层反应谱、最大相对位移、最大加速度的影响规律,从而为核反应堆厂房结构设计提供理论依据。

The factors which influence the seismic responses of nuclear engineering structure include the properties of earthquake, soil and structures. In this paper, for the purpose of the reactor building of nuclear station, the influence of the floor response spectra possessing multi-damping and other seismic responses of nuclear reactor building under the condition of inhomogeneous foundation soil is investigated by considering the soil-structure interaction （SSI）. Seismic responses of reactor are calculated by using SUPERFLUSH/2D software, the finite element model of foundation is made by utilizing ANSYS ; the finite element model of reactor based on lumped-mass model is constructed by using SUPERFLUSH/2D. In the finite element method, the energy transfer boundary conditions at the bottom and sides of the model can be considered. The wave energy is transferring at the bottom of model. The wave dispersion fluctuation appears on both sides of model. The influence of foundation inhomogeneity on the floor spectra, maximum relative displacement and maximum acceleration of the nuclear reactor building is revealed by the numerical simulation, which provides a theoretical reference for structural design of nuclear reactor plant.