基于极大初始时间步法的核电厂取水构筑物两侧翼墙抗震安全分析

Seismic safety analysis of two-side wing wall of nuclear power plant based on maximum initial time-step method

压水堆（PWR）核电厂取水构筑物两侧翼墙是核电厂海域工程的重要组成部分,属于抗震类别Ⅰ类,其受复杂非均质地基的影响不容忽视。以某压水堆核电厂取水构筑物翼墙为研究对象,推导了基于极大初始时间步的粘弹性人工边界静动力联合分析模型,用以考虑结构-地基相互作用效应（即SSI效应）。利用有限元分析软件ANSYS建立了翼墙-地基三维静动力计算模型,模拟分析了非均质地基的几何形态复杂性。通过静动力联合分析结果与静力分析结果的对比,验证了所开发静动力模型的合理适用性。对翼墙开展了静动力联合分析,探讨翼墙的主应力分布规律和其关键部位在重力、静水压力、动水压力及地震等荷载效应组合下的加速度变化情况和结构构件内力分布规律,综合评价翼墙基础底面接地率、抗滑和抗倾覆稳定性等。计算方法和分析成果可为压水堆核电厂翼墙及类似结构的抗震安全评价与优化设计提供参考。

The two-side wing wall of a pressurized water reactor（PWR） nuclear power plant is an important part for marine engineering of nuclear power plant. It belongs to the anti-seismic category I,and the influence of its complex heterogeneous foundation cannot be ignored. According to a practical situation of a PWR nuclear power plant,the viscoelastic artificial boundary model combined static and dynamic analysis based on the maximum initial time-step was derived to consider the soil-structure interaction effect（SSI effect）. The three-dimensional static and dynamic model of wing wall foundation was established,and the geometrical complexity of non-homogeneous foundation was stimulated by the finite element analysis software ANSYS. The developed static and dynamic model was proved to be reasonable and applicable by the comparison between static and dynamic analysis results and static analysis results. The combined static and dynamic analysis of wing wall was carried out to investigate the distribution of the principal stress of the wing wall and the acceleration change and internal force distribution rules of structure under some conditions were evaluated comprehensively,for instance,under the condition of gravity, hydrostatic pressure, dynamic water pressure and seismic load effect. The grounding rate,anti-sliding,and anti-overturning stability of the wing wall foundation were evaluated. The calculation method and analysis results can provide reference for the seismic safety evaluation and optimization design of wing wall and similar structures in pressurized water reactor nuclear power plant.