| With the rapid development of super high-rise buildings in recent years,the application of tube-in-tube structure is more than before.The giant column plays the most important role in the whole structure.Because of the importance of mega column,it will cause risks for the project if there isn’t deep researches,acceptable qualities,correct constructions and qualified steel and concrete structures.It will also affect the safety of the whole project.High efficiency,simple and perfect construction technology can not only furthest reduce hidden danger,but also greatly improve the construction efficiency.The current researches on mega column construction at home and abroad mainly focus on the node stress simulation analysis.There is no Mega column construction research on the whole.But in fact,the force of each node in the whole structure is complex.It is easy to divorce theory from reality.This research relies on theconstruction sites,theoretical analyses comparison and experimental data.The author combined theory with practice,and study the structure on the whole,instead of the separate steel structure and the concrete structure apart.What’s more,the author launched a comprehensive study about the mega columns of steel structures,concrete mixing,ultra-high pressure pump and other key technologies,which provides theoretical and technical support to promote the development of super high-rise.There are the main aspects of the research in this paper:(1)The development of super high-rise steel structure is not complete,especially the researches on large section steel column.The author researched on section,mega column of steel structure hoisting,measurement,welding and other key technologies through studying the existing literature and the successful cases of related engineering.(2)This paper analyzes the particularity of the environment and the pouring way of the concrete in the steel pipe column.The author carried on the experimental research about the concrete mixing proportion,which took the C70 high strength concrete as an example.(3)In this article,three kinds of pouring methods that are commonly used are analyzed.Combined with the complexity of the giant column cavity concrete pouring,the author did lots of experiments onHigh Self-Compacting Method,and finally decided to use this method to pour concrete.(4)At present,there is a lack of experience in super high pressure pumping in China.This paper learned from the experience about construction at home and abroad,then made a deep research on the ultra-high pressure pump mechanical and piping layout,and did a detailed analysis.It is shown in the results that the steel structure plays an important role in the wholesystem,we must keep designing before construction,and do according to what have been designed strictly in the following process.There should be strict measurement correction before welding.When welding,we should take various measures to ensure the stability of the process.Because of the particularity of the mega columns inside the concrete,mobility and stability should be considered first when designing the proportion.Also,we need to add curing agent in internal curing.Finally,the author decided on High Self-Compacting Method to pour concrete. |
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