桩基核岛结构三维地震反应分析简化方法  

A simplified method for 3D seismic response analyses of a pile-founded nuclear-island building

作　　者：李文彪 蒋家卫 陈国兴[1,2] 朱升冬 Li Wenbiao;Jiang Jiawei;Chen Guoxing;Zhu Shengdong(Institute of Geotechnical Engineering,Nanjing Tech University,Nanjing 210009,China;Civil Engineering and Earthquake Disaster Prevention Center of Jiangsu Province,Nanjing 210009,China;Fujian Yongfu Power Engineering Co.,Ltd.,Fuzhou 350108,China)

机构地区：[1]南京工业大学岩土工程研究所,江苏南京210009 [2]江苏省土木工程防震技术研究中心,江苏南京210009 [3]福建永福电力设计股份有限公司,福建福州350108

出　　处：《土木工程学报》2025年第2期86-96,128,共12页China Civil Engineering Journal

基　　金：国家重点研发计划项目(2018YFC1504301)。

摘　　要：核岛可能会受到潜在强地震的严重威胁。土-桩-核岛结构动力相互作用效应分析是桩基核岛结构抗震设计的核心问题。针对我国某拟建核电厂,以3D集中质量-梁杆模型模拟AP1000核岛结构,建立土质地基-群桩基础-核岛结构体系的3D整体有限元模型和简化模型。在该简化模型中,采用“等效单桩”代替群桩基础,采用Penzien集中质量模型模拟土-桩-结构动力相互作用,采用土弹簧模拟土-核岛底板动力相互作用。选取频谱特性差异显著的近场中强震、中-远场强震和远场大震记录作为输入基岩地震动,采用广义non-Masing滞回本构模型考虑土的动力非线性特性,对比分析3D简化模型和整体有限元模型计算的核岛结构(屏蔽建筑和安全壳)地震反应特征。结果表明:2种模型计算的核岛结构水平向和竖向峰值加速度、水平向峰值相对位移随高度的变化以及屏蔽建筑顶部水箱晃动水的水平向谱加速度β谱的值均基本吻合;在低频丰富的强地震动作用下,2种模型计算的核岛结构顶部的竖向谱加速度β谱的值基本一致。这表明简化方法能合理模拟桩基核岛建筑结构的地震反应特征,可作为桩基核岛结构地震反应分析的一种辅助方法。Nuclear-islands may be seriously influenced by potentially strong earthquakes.Soil-structure dynamic interaction effect analysis is a key procedure for the seismic design of pile-founded nuclear-island buildings(NIBs).Aiming at a proposed nuclear power plant in a coastal region of China,a 3D lumped-mass stick(LMS)model is utilized to simulate the AP1000 NIB,and a 3D integral finite element model and a simplified model of the site-group pile-nuclear island structural system are established.In this simplified model,by introducing the concept of“equivalent monopile”,the effect of soil-pile-group dynamic interaction can be captured properly by the soil-equivalent monopile dynamic interaction.The Penzien lumped mass model is applied to simulate the soil-pile-group-superstructure dynamic interaction,and soil springs are applied to simulate the soil-nuclear-island mat interaction.Based on the generalized non-Masing hysteretic constitutive model of soil,some results are obtained from a simulation study of the 3D integral finite element model and the simplified model,by which the seismic responses of NIB(i.e.,shielded building and containment vessel)subjected to near-field moderate-strong earthquake,moderate-far field strong earthquake,and far-field large earthquake scenarios,are analyzed respectively.The results computed by the two models show that the horizontal and vertical peak accelerations and the horizontal peak relative displacements along the vertical direction of NIB,as well as theβspectra of horizontal spectral acceleration of the sloshing water in the top of shielded building are similar to each other.Furthermore,theβspectral curves of vertical spectral accelerations at the top of NIB computed by the two models are also similar under the far-field large earthquake scenarios with rich in lowfrequency contents.It is revealed that the seismic response characteristics of pile-founded NIB can be properly captured by the equivalent monopile-based simplified mode.The proposed method can act as an auxiliary meth

关 键 词：核岛结构 地震反应特征 土-桩-结构动力相互作用 等效单桩 三向地震动 

分 类 号：TU43[建筑科学—岩土工程]