上部大跨钢结构与下部混凝土结构协同工作研究

发布时间：2018-05-02 19:53

本文选题：协同工作 + 混合结构　；参考：《清华大学》2015年硕士论文

【摘要】：上部屋盖采用大跨钢结构、下部支承结构采用混凝土结构是常见的一种大跨度混合结构形式。对于此类混合结构体系,现阶段的工程设计大多将上部大跨钢结构与下部混凝土支承结构分开进行设计计算。在对上部大跨钢结构单独进行计算分析时,边界条件采用简化的简支支座或固定支座形式。然而这样的简化方式并不能够准确反映混合结构体系的实际受力状况,因此通过整体结构建模进行此类混合结构的计算分析以考虑上下部结构间的协同工作效应非常有必要。本文通过对某文化遗址护棚结构、北京将台商务中心冬季花园结构、武汉银河汇主入口屋盖和武钢体育中心游泳馆四个工程实例的计算分析,对比了考虑协同工作与否计算结果的差异。同时对采用弹性支座对下部支承结构的模拟问题、选取不同界限内支承结构考虑协同工作的问题也进行了分析。论文主要结论如下:(1)考虑上部大跨钢结构与下部混凝土支承结构的协同工作后,整体结构模型计算结果在周期模态、支座反力、杆件内力、单元应力分布、结构位移及整体稳定性等方面均与独立上部大跨钢结构模型存在差异,且整体模型的计算结果多数偏于不利,因而对于此类混合结构进行整体建模计算很有必要;(2)在静力荷载作用、反应谱分析、动力时程分析及整体稳定性分析时,采用弹性支座模型的计算结果多介于独立上部大跨钢结构模型与整体结构模型之间,弹性支座模型能够对上部大跨钢结构与下部混凝土支承结构体系的协同工作进行较好的模拟;(3)对于下部支承结构体量比上部大跨钢结构体量大很多的混合结构,可以仅选取部分界限内的支承结构来考虑协同工作效应,部分支承结构模型的计算结果与全部支承结构模型计算结果的分布规律相似,数值大小接近,仅选取部分支承结构考虑协同工作有一定的合理性;(4)考虑上下部结构协同工作后对下部混凝土支承结构的影响,主要体现在下部混凝土结构的层间位移角和扭转位移比多数得到了放大,框架柱的轴压比也略有变化,进一步说明进行上下部结构整体建模分析的必要性;(5)弹性支座模型及考虑部分支承结构的整体模型并不是对上部大跨钢结构与下部混凝土支承结构体系协同工作的精确模拟。条件允许情况下,仍然建议建立包含全部上下部结构的整体模型进行结构的静动力和整体稳定性分析。
[Abstract]:Long span steel structure is used in the upper roof and concrete structure is used in the lower supporting structure. For this kind of hybrid structure system, most of the present engineering designs separate the upper long-span steel structure from the lower concrete supporting structure. In the calculation and analysis of the upper long span steel structure, the boundary condition is simplified simply supported or fixed support. However, this simplified method can not accurately reflect the actual force situation of the hybrid structure system, so it is very necessary to calculate and analyze this kind of hybrid structure by modeling the whole structure to consider the cooperative work effect between the upper and lower structures. Through the calculation and analysis of the structure of a cultural site, the winter garden structure of Beijing Jiantai Business Center, the main entrance roof of Wuhan Yinhe Huihui and the Swimming Pool of Wuhan Iron and Steel Sports Center, The difference between the calculation results considering cooperative work or not is compared. At the same time, the problem of using elastic support to simulate the lower support structure is also analyzed, and the problem of considering the cooperative work of the supporting structure within different boundaries is also analyzed. The main conclusions of the paper are as follows: (1) considering the cooperative work between the upper long-span steel structure and the lower concrete supporting structure, the calculation results of the whole structure model are in the periodic mode, the support reaction force, the internal force of the member, and the stress distribution of the element. The structural displacement and global stability are different from those of the independent upper large-span steel structure model, and the calculation results of the whole model are mostly unfavorable. Therefore, it is necessary to carry out integral modeling and calculation for this kind of hybrid structure, when static load, response spectrum analysis, dynamic time history analysis and global stability analysis are used. The calculation results of the elastic support model are mostly between the independent upper large span steel structure model and the integral structure model. The elastic support model can be used to simulate the cooperative work between the upper long-span steel structure and the lower concrete supporting structure system. For the hybrid structure with lower support structure, the volume of the lower support structure is much larger than that of the upper large span steel structure. The cooperative working effect can only be considered by selecting the supporting structure within the partial limit. The results of the partial support structure model are similar to the results of the whole supporting structure model, and the numerical value is close to that of the whole supporting structure model. It is reasonable to select only part of the supporting structure to consider the cooperative work. 4) considering the influence of the upper and lower parts of the structure on the lower concrete supporting structure after the cooperative work of the upper and lower parts of the structure. Most of the interstory displacement angle and torsional displacement ratio of the lower concrete structure are magnified, and the axial compression ratio of the frame column is also slightly changed. It is further explained that the necessity of overall modeling and analysis of upper and lower parts of the structure is that the elastic support model and the integral model considering partial support structure are not accurate simulation of the cooperative work between the upper long span steel structure and the lower concrete supporting structure system. If conditions permit, it is still suggested to establish a global model containing all the upper and lower structures to analyze the static, dynamic and global stability of the structures.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU398.9

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