地震波斜入射条件下核安全壳的地震响应分析

发布时间：2018-03-10 12:24

本文选题：核电站　切入点：安全壳　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：人类对于资源大幅度的需求对核能源的快速发展起到推动作用。核能源作为污染低、能量高效的能量资源受到了国内外广泛青睐。然而,近几年核事故带给人类社会的伤害也不容忽视,探究核事故的诱因,地震灾害是一个重要的因素。尽管地震偶然发生,但是悉数近几年我国发生的大震,灾后的景象依然触目惊心。目前国内外很多学者针对核电站的地震作用下的动力响应和抗震性能的评估已做出很多相关研究,但是在考虑土-结构相互作用下的建筑结构的地震响应分析时,一般假定输入的地震波是垂直作用在建筑模型底部的剪切地震波或者是压缩地震波。然而由研究可知只有当地震波源距离结构场地非常远时,地震波经过不断折射,垂直入射的假定才是能够接受的。因此当震源距离结构场地比较近时,不能假定它的入射方向是垂直的,而是以某个入射角度传播到场地结构上的,此时的地震动就表现出了空间变化的特性。由于地震波斜入射情况产生的地表运动的非一致性变化,会对核电站、水坝、桥隧以及地铁站等大型建筑物的地震动力响应造成很大的影响,因此当近场发生较大地震时,为了保证这些大型建筑结构在地震作用下的安全性,必须在抗震结构设计中考虑地震波的入射角度问题。本文主要研究内容如下:1、建立了土体模型,并且在土体黏弹性边界的基础上运用波场分解原理实现地震动到黏弹性边界上等效地震荷载作用力的转化,通过数值算例验证了波场分解输入方法的正确性。2、基于大型通用有限元软件ABAQUS建立精细化核电站安全壳结构的数值模型,在考虑土-结构相互作用下完成核安全壳的SSI模型建立。3、基于建立的核安全壳的SSI模型,选取P波和SV波两种类型的地震波以不同的入射角度输入来对核安全壳结构进行地震动力响应分析,研究得出一些重要结论:在地震波斜入射条件下核安全壳的动力响应与地震波垂直入射下对比,核安全壳的地震动动力反应有明显区别,斜入射条件下对结构更不利。因此当对核安全壳进行安全评估以及结构设计时,有必要去考虑地震波斜入射带来的影响。
[Abstract]:The rapid development of nuclear energy is promoted by the great demand of human resources. Nuclear energy, as a kind of energy resource with low pollution and high energy efficiency, is widely favored at home and abroad. The damage caused by nuclear accidents to human society in recent years cannot be ignored. Exploring the causes of nuclear accidents, earthquake disasters are an important factor. Although earthquakes happen by chance, all the major earthquakes that have occurred in China in recent years, The scene after the disaster is still shocking. At present, many scholars at home and abroad have done a lot of relevant research on the evaluation of dynamic response and seismic performance of nuclear power plants under earthquake. However, when considering the seismic response of a building structure under soil-structure interaction, It is generally assumed that the input seismic waves are shear or compressed seismic waves acting perpendicular to the bottom of the building model. However, the study shows that the seismic waves refraction continuously only when the seismic wave source is very far from the structural site. The assumption of vertical incidence is acceptable. Therefore, when the source is close to the site of the structure, it cannot be assumed that the direction of incidence is vertical, but propagates to the site structure at a certain incidence angle. At this point, the ground motion shows the characteristics of spatial variation. Because of the inconsistency of the ground motion caused by the oblique incidence of seismic waves, it will affect the nuclear power plant, the dam, The seismic dynamic response of large buildings, such as bridges, tunnels and subway stations, has a great impact, so when a large earthquake occurs in the near field, in order to ensure the safety of these large building structures under earthquake, The incident angle of seismic wave must be considered in the design of seismic structure. The main contents of this paper are as follows: 1. The soil model is established. On the basis of viscoelastic boundary of soil mass, the equivalent seismic load force is transformed from ground motion to viscoelastic boundary by using wave field decomposition principle. The correctness of the wave field decomposition input method is verified by a numerical example. The numerical model of elaborate containment structure of nuclear power station is established based on the large-scale general finite element software ABAQUS. Under the consideration of soil-structure interaction, the SSI model of nuclear safety shell is built. 3, based on the SSI model of nuclear safety shell, Two types of seismic waves, P wave and SV wave, are selected to analyze the seismic dynamic response of nuclear safety shell structure with different incident angles. Some important conclusions are drawn: the dynamic response of the nuclear safety shell under the condition of oblique incidence of seismic wave is obviously different from the dynamic response of the nuclear safety shell under the vertical incidence of the seismic wave. Therefore, it is necessary to consider the influence of oblique incidence of seismic waves when evaluating the safety of nuclear safety shells and structural design.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TL364.3;TU311.3

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