超大型冷却塔结构地震反应分析及试验研究

发布时间：2018-01-06 06:04

本文关键词：超大型冷却塔结构地震反应分析及试验研究　出处：《中国地震局工程力学研究所》2015年博士论文　论文类型：学位论文

【摘要】：近年来,随着国家环保战略的要求,我国三北地区正在酝酿建造一批1000MW超临界空冷机组,与之相匹配的间接冷却塔结构一般高达200米以上、直径达180米以上、进风口高度达30米以上。建设地点多位于南北地震带中北段,地震危险性高,场地条件复杂。其抗震设计必须面对高烈度、土-结构相互作用以及行波效应等难题。而目前国内外关于超大型冷却塔结构高烈度抗震设计问题的相关研究资料很少,可参考资料更是罕见。围绕这一问题,本文采用地震模拟振动台试验与有限元数值模拟分析相结合的手段,对超大型冷却塔结构的地震破坏机理、土-结构相互作用、行波效应及其隔震可行性等问题进行了研究探讨,主要完成了以下几方面的工作:1.采用欠人工质量相似理论设计了原型高度为220米直径为188米的超大型冷却塔结构1:30缩尺试验模型。通过地震模拟振动台试验,获得了考虑不同场地条件的不同烈度工况下超大型冷却塔模型结构的动力响应、振动特性及其破坏特征,研究揭示了超大型冷却塔结构的地震作用破坏机理,发现超大型冷却塔结构下部的X型支柱上下端部、筒壁最薄的塔筒喉部是其地震薄弱部位,为超大型冷却塔结构优化抗震设计提供了依据。通过模型结构有限元数值模拟并与试验结果的对比分析,交互验证了有限元数值模型与试验模型的合理性。2.针对II、III类场地条件下高大结构实际存在的地基土-结构相互作用效应问题,提出了对设计谱水平地震最大影响系数max?采用修正系数s?进行调整的方法,以简化超大型冷却塔结构抗震设计分析过程。采用粘弹性阻尼单元模拟地基土边界,以某超大型冷却塔结构原型为例进行了地基土-结构相互作用分析。通过对比分析是否考虑土-结构相互作用两个模型的结构动力特性及地震反应,给出了II、III类场地条件下考虑土-结构相互作用时冷却塔结构的动力反应规律。3.综合考虑行波效应不利影响,提出了对设计谱水平地震最大影响系数max?采用修正系数T?调整的方法,以简化超大型冷却塔结构抗震分析过程。仍以前述超大型冷却塔结构为例,进行了是否考虑土-结构相互作用效应的超大型冷却塔结构行波效应对比分析,指出视波速?1000 m/s的I类场地条件下超大型冷却塔抗震分析可以不考虑行波效应;视波速?350 m/s的II~III类场地条件下,建议超大型冷却塔结构中应对超大型冷却塔行波效应给予足够重视。4.给出了超大型冷却塔结构采用橡胶支座基础隔震技术的设计分析方法。本文采用有限元分析方法,对比研究了是否考虑土-结构相互作用、是否考虑行波效应等条件下超大型冷却塔结构采用基础隔震的减震效果。以8,9度抗震设防为例,证明了超大型冷却塔结构采取基础隔震措施后上部结构各关键节点之间的地震反应相对位移、加速度以及X型支柱位移角均能有效降低,可大幅提升超大型冷却塔结构的地震安全性。
[Abstract]:In recent years, with the national environmental strategy, north areas of China is preparing to build a batch of 1000MW supercritical air cooling unit, indirect cooling tower structure to match the average as high as 200 meters, diameter of 180 meters, the air inlet height of 30 meters. The construction site located in the northern section of North South seismic with high seismic hazard, site condition is complex. The seismic design must face high intensity, soil structure interaction and the traveling wave effect problem. And at present very few domestic and foreign related research about super large cooling tower structure in high seismic design information, reference is rare. Around this issue, this paper adopts the finite element and the shaking table test method of numerical simulation analysis, failure mechanism of super large cooling tower structure earthquake, soil structure interaction, and the feasibility of seismic traveling wave effect etc. The problems are discussed, mainly completed the following work: 1. using under artificial quality similarity theory to design the prototype height of super large cooling tower structure of 1:30 scale test model of 220 meters to 188 meters in diameter. Through shaking table test, the dynamic response of super large cooling tower model is obtained considering the different site conditions of different intensity conditions, vibration characteristics and failure characteristics, study reveals the seismic effect of super large cooling towers of the failure mechanism, find the X - pillar super large cooling tower on the lower part of the lower part of the tower cylinder wall of the throat, thin is the seismic weak parts, provide the basis for super large cooling the tower structure optimization of seismic design. Through comparative analysis of finite element model and numerical simulation and experimental results verify the rationality of the.2. interaction, finite element numerical model and test model According to II, soil III site under the condition of tall structure the actual structure interaction problems, put forward the design of horizontal earthquake influence coefficient maximum spectrum max? The correction coefficient s? Method of adjustment, in order to simplify seismic super large cooling tower structure design analysis process. Using viscoelastic damping element to simulate the foundation the soil boundary, a super large cooling tower structure as an example to analyze the prototype of soil structure interaction. Through the comparative analysis of whether considering the soil structure interaction of two model structure dynamic characteristics and seismic response, to II, when the adverse effects of dynamic response of.3. cooling tower structure considering traveling wave effect considering soil structure interaction III site conditions, proposed to the design level earthquake influence coefficient maximum spectrum max? The correction coefficient T? Method of adjustment to simplify the super large cooling tower Process. Seismic analysis of structures in these super large cooling tower structure as an example, to consider whether the comparative analysis of super large cooling tower structure of the traveling wave effect of soil structure interaction, pointed out that the apparent velocity of 1000 m/s? I site under the condition of super large cooling tower seismic analysis can not consider the traveling wave effect; wave velocity 350? M/s II~III site conditions, with super large cooling tower structure in super large cooling tower traveling wave effect is given enough attention given by.4. is adopted in the design of super large cooling tower structure of rubber base isolated technology analysis method. This paper uses the finite element analysis method, comparative study of whether considering soil structure interaction whether, considering the traveling wave effect under the condition of super large cooling tower structure with damping effect of base isolation. With the 8,9 degree earthquake as an example, proves that the super large cooling tower structure to base After the base isolation measures, the relative displacement, acceleration and X pillar displacement angle between the key nodes of the upper structure can be effectively reduced, and the seismic safety of the super large cooling tower structure can be greatly improved.

【学位授予单位】：中国地震局工程力学研究所
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TU347;TU311.3

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