超高层混合结构体系施工竖向变形及塔吊支撑架附着节点加固分析

发布时间：2018-12-18 21:08

【摘要】：近年来,超高层钢框架-混凝土核心筒混合结构作为一种新型结构体系在我国得到迅速发展。对于高层混合结构的竖向变形分析和塔吊附着节点的研究,是一项很重要的内容。本文以某写字楼为工程背景,对超高层混合结构的竖向变形分析以及外爬式塔吊支撑架对核心筒的影响进行研究,主要研究内容及结论如下： (1)以高度为300m的某写字楼为例,利用MIDAS/Gen有限元分析软件,在不考虑基础沉降变形的前提下,采用欧洲混凝土结构模式规范CEB-FIP (MC90)描述混凝土的收缩徐变,研究了混凝土收缩徐变、施工速率、施工找平和核心筒领先施工层数等时变因素和工程措施对竖向变形的影响,得到如下结论：整体结构模型与施工阶段模型的分析结果存在着较大的差异,应采用考虑混凝土收缩徐变的施工阶段模型；施工速率对结构竖向变形的影响较小；核心筒先行施工层数越多,越利于减小钢框架柱与核心筒竖向变形差；收缩徐变增大柱筒变形差,由于收缩徐变作用,随着结构完成后时间推移,结构的内外变形差会不断增大；混凝土的收缩徐变造成了连接核心筒与外框架的梁支座端部剪力及负弯矩变化,连接外钢框架柱一端梁支座端部剪力及负弯矩增加,而连接核心筒一端则减小。 (2)结合工程实例,建立外爬式塔吊支撑架模型,分析了外爬式塔吊附着节点预埋件的受力性能及其对附着墙体抗冲切性能的影响,并提出了爬塔支撑架预应力拉索加固方案。加固后的支撑架改变了节点的受力情况,可避免附着混凝土墙体的开裂,从而保证了节点安全。
[Abstract]:In recent years, as a new type of structural system, super-tall steel frame-concrete core-tube hybrid structure has been developed rapidly in China. It is very important to analyze the vertical deformation of high-rise hybrid structures and to study the attached joints of tower cranes. Based on the engineering background of an office building, this paper studies the vertical deformation analysis of super high-rise hybrid structure and the influence of the external climbing tower crane on the core tube. The main research contents and conclusions are as follows: (1) taking an office building with a height of 300m as an example, using MIDAS/Gen finite element analysis software, without considering the settlement deformation of foundation, CEB-FIP (MC90) is used to describe the shrinkage and creep of concrete. The shrinkage and creep of concrete and the construction rate are studied. The influence of time varying factors and engineering measures on vertical deformation of construction leveling and core tube leading construction is obtained as follows: there are great differences between the analysis results of the integral structure model and the construction stage model. The construction stage model considering concrete shrinkage and creep should be adopted. The construction rate has little effect on the vertical deformation of the structure, and the more the number of the core tube is, the more the vertical deformation difference between the steel frame column and the core tube is reduced. Shrinkage and creep increase the difference of cylinder deformation. Due to the effect of shrinkage and creep, the difference between internal and external deformation of the structure will increase with time after the completion of the structure. The shrinkage and creep of concrete cause the change of shear force and negative bending moment at the end of the beam support connecting the core tube and the outer frame. The shear force and negative bending moment of the end of the beam support at the end of the connecting steel frame column increase, but the end of the connection core tube decreases. (2) combined with the engineering example, the model of the external climbing tower crane support frame is established, and the mechanical behavior of the embedded part of the attachment joint of the outer climbing tower crane and its influence on the impact and shear behavior of the attachment wall are analyzed. The scheme of prestressed cable reinforcement of climbing tower support frame is put forward. The strengthened bracing can change the stress of the joint, avoid the crack of the attached concrete wall, and ensure the safety of the joint.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU974

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