大底盘双塔结构地震作用效应影响因素研究

发布时间：2018-05-23 18:54

本文选题：大底盘双塔结构 + 水平地震振型　；参考：《中南林业科技大学》2017年硕士论文

【摘要】：大底盘多塔楼属于复杂高层结构,它的体型庞大复杂,平面不规则,刚度分布不均匀,在地震作用下会产生复杂的扭转,其设计及抗震研究难度高。当前对大底盘多塔楼的研究还不够成熟,尤其在它的抗震方面,振型多而复杂,研究起来也相当困难,到目前为止还没有出现一套完整的设计理论,所以对该类结构的研究是很有必要的。本文对大底盘双塔结构地震作用影响因素进行了比较全面的研究。改变影响水平地震作用效应的因素,对比改变前后的周期、振型、内力及位移特点,并提出了简化计算方法。本文首先介绍了大底盘双塔结构的最常用的理论分析方法--反应谱法,通过对反应谱理论的推导,分析了双塔结构的振型参与系数及结构地震响应,根据五种基本振型从振型分解反应谱法的角度分析了结构的振动特点。应用大型有限元软件MIDAS GEN对结构建立基本模型,通过改变影响因素,如塔楼层数、大底盘层数、楼面板厚度、塔楼位置、楼板开洞以及嵌固端的位置等对结构分别进行了全面的对比分析,对比了各结构模型在改变影响因素前后的地震反应特点,包括振型周期等结构自振特性以及地震力、内力与位移等地震作用效应,对某些结构还比较了结构中某些特殊的局部杆件的内力及位移。根据对比结果得出了相关影响因素对结构的影响程度及在大底盘设计时应注意的问题,研究表明,大底盘层数和刚度、塔楼的层数和位置的改变均对结构有一定的影响。最后研究了结构分析的简化方法,一种是把双塔结构剖分为两个单塔结构进行分析,对比了单塔结构与双塔结构的地震反应特点,对称双塔结构的大底盘对双塔有约束和协调作用,其塔楼部分的内力及位移均略小于大底盘单塔结构,在某些情况下大底盘对称双塔结构可以剖分为单塔计算;一种为改变嵌固端位置,分析不同嵌固端位置对结构地震效应的影响,提出简化方法应注意的问题。
[Abstract]:The large chassis multi-tower is a complex high-rise structure with large and complex shape, irregular plane and uneven stiffness distribution, which will produce complex torsion under the action of earthquake, and its design and seismic research are very difficult. At present, the research on large chassis and multi-tower buildings is not mature enough, especially in the aspect of earthquake resistance, the vibration modes are many and complex, and it is quite difficult to study. So far, there has not been a complete set of design theory. So it is necessary to study this kind of structure. In this paper, the influencing factors of seismic action of large chassis double tower structures are studied comprehensively. The influence factors of horizontal earthquake action are changed, and the characteristics of period, mode shape, internal force and displacement before and after the change are compared, and a simplified calculation method is put forward. In this paper, the most commonly used theoretical analysis method of large chassis double-tower structure, the response spectrum method, is introduced in this paper. Through the derivation of the response spectrum theory, the mode participation coefficient and the seismic response of the double-tower structure are analyzed. The vibration characteristics of the structure are analyzed from the viewpoint of the mode decomposition response spectrum method according to the five basic modes. The basic model of the structure is established by using the large-scale finite element software MIDAS GEN. By changing the influencing factors, such as the number of tower floors, the number of large chassis floors, the thickness of floor panel, the position of tower, In this paper, the structure is compared and analyzed in detail, such as the opening of floor slab and the location of the fixed end. The seismic response characteristics of each structural model before and after changing the influencing factors are compared, including the natural vibration characteristics and seismic forces of the structure, such as the mode period, and so on. For some structures, the internal forces and displacements of some special local members are also compared. According to the results of comparison, the influence degree of related factors on the structure and the problems that should be paid attention to in the design of large chassis are obtained. The study shows that the change of floor number and stiffness of large chassis and the change of floor number and position of tower have certain influence on the structure. Finally, the simplified method of structural analysis is studied. One is to divide the double tower structure into two single tower structures for analysis, and to compare the seismic response characteristics between the single tower structure and the double tower structure. The internal force and displacement of the tower part are slightly smaller than that of the large chassis single tower structure. In some cases, the symmetrical double tower structure with large chassis can be divided into single tower structure. In order to change the fixed end position and analyze the influence of different fixed end position on the seismic effect of the structure, the paper puts forward some problems that should be paid attention to in the simplified method.
【学位授予单位】：中南林业科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU973.31

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