框架—核心筒结构竖向收缩徐变效应施工模拟分析

发布时间：2018-11-14 08:07

【摘要】：高层、超高层建筑为了更好的适应建筑平面使用、空间分割、景观视野等建筑功能的需求，现在多趋向采用框架—核心筒这一结构体系[1]。广泛应用于写字楼、酒店、多功能建筑。但是随着建筑高度越来越高，不同竖向构件间的竖向变形差成为必须考虑的问题。本文首先介绍了混凝土收缩徐变的机理、收缩徐变的各种影响因素和估算方法、变应力作用下徐变的计算理论。接着对简单结构进行计算分析，对比不同加载方式、是否考虑收缩徐变和混凝土材料时变特性计算结果的差异，得出采用施工模拟计算结构竖向变形的必要性。然后以实际工程混凝土框架—核心筒结构为计算原型，采用建筑结构通用有限元软件Midas/gen对结构进行竖向弹性、收缩徐变变形分析，总结变形规律。提出了建筑墙体滞后主体结构施工且采用ACI+PCA收缩徐变计算模型的精确施工模拟方法。通过模型计算考虑了竖向变形的影响因素，得出结论：施工速度和配筋率影响较大；且施工速度越快总变形越大、配筋率越大徐变越小；环境相对湿度影响较小。接着比较了混凝土框架—核心筒结构不同时期墙柱之间的变形差，用不同分析方法计算梁中弯矩、剪力、柱中轴力，找到变化规律。对钢管混凝土柱框架—核心筒结构的钢管柱采用特殊处理方法分析结构竖向构件的变形差、变形引起的内力。提出与墙平面外相连接钢梁墙端滞后5层刚接的处理办法，解决了墙端弯矩过大的问题。最后本文在对框架—核心筒竖向变形差效应分析的基础上，，提出从混凝土材料、结构设计及施工方面对竖向变形差采取对策。
[Abstract]:In order to better meet the needs of building functions such as plane use, space segmentation, landscape view and so on, high-rise and super-high-rise buildings tend to adopt the frame-core tube structure system [1]. Widely used in office buildings, hotels, multi-purpose buildings. However, with the building height becoming higher and higher, the vertical deformation difference between different vertical members must be considered. In this paper, the mechanism of shrinkage and creep of concrete, the influence factors of shrinkage and creep and the calculation method of creep under variable stress are introduced in this paper. Then the simple structure is calculated and analyzed, and the difference between shrinkage and creep and time-varying characteristics of concrete material is considered by comparing different loading methods, and the necessity of using construction simulation to calculate the vertical deformation of the structure is obtained. Then, taking the concrete frame-core tube structure as the calculation prototype, the vertical elastic, shrinkage and creep deformation of the structure is analyzed by using the general finite element software Midas/gen, and the deformation law is summarized. An accurate construction simulation method based on ACI PCA shrinkage and creep calculation model is put forward in this paper. The influence factors of vertical deformation are taken into account in the model calculation. It is concluded that the construction speed and the reinforcement ratio have a great influence; and the faster the construction speed the bigger the total deformation, the greater the reinforcement ratio is and the smaller the creep rate is, and the less the influence of environmental relative humidity is. Then the difference of deformation between wall and column in different periods of concrete frame-core tube structure is compared, and the bending moment, shear force and axial force in column are calculated by different analysis methods, and the variation law is found. The concrete filled steel tube column with concrete filled steel tube frame and core tube structure is treated with special treatment method to analyze the deformation difference and internal force caused by the deformation of the vertical member of the structure. In this paper, a method for solving the problem of excessive bending moment at the end of a steel beam is put forward, in which the end of the steel beam is connected with the external phase of the wall with a lag of 5 stories. Finally, on the basis of the analysis of the vertical deformation difference effect of frame-core tube, this paper puts forward some countermeasures to the vertical deformation difference from the aspects of concrete material, structure design and construction.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU973.17

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