Analysis And Design Of Concrete Filled Steel Tube Structure Subjected To Lateral Loading

Abstract

Steel-concrete composite columns are used extensively in modern buildings. Exten- sive research on composite columns in which structural steel section is encased in concrete have been carried out.In- lled composite columns, however have received limited attention compared to encased columns. In this work, review is carried out on composite columns with emphasis on analytical work. Also it includes review of re- search work that has been carried out to date, accounting the e ects of local buckling, bond strength, lateral loading, con nement of concrete and behavior of steel-concrete composite columns. Analytical studies of behavior of concrete lled circular steel tubes under lateral loading and study of interactions between steel tube and concrete lled is done. The behavior of the Concrete lled steel tube columns is controlled by both the strength and con nement e ect of steel tube and concrete lled in the columns. The con ne- ment provided by a closed steel section allows higher strengths to be attained by the concrete. Circular concrete- lled tubes develop hoop-tension which further increases the overall load-carrying capacity of the concrete. The objective of the present study is to understand the behavior of the concrete lled tube structural system for high-rise building and to design structural systems includ- ing e ects of the lateral loading. Also study the con nement e ect on concrete due to steel tube is done. Comparative study of concrete lled tube (CFT), R.C.C and steel structure with di erent storey height of 10, 20 and 30 stories. With all structural systems as frame structure is carried out. Determination of the design load-carrying capacity and subsequently comparison to several building codes was done. It also shows that the use of concrete lled steel tube columns that now have been consistently applied in the design of tall buildings provide considerable economy in comparison with conventional steel columns. Their use, allows the adoption of steel or composite oor systems combined with economically constructed columns. The use of these columns also has considerable advantages over reinforced concrete columns as they allow higher percentages of reinforcement to be adopted. Reduction in the column size can provide signi cant economic bene t since use of high strength steel can be applied in these situations. The use of composite columns becomes much more attractive where the need for high strength within a small "footprint" and good intrinsic re resistance are considered more important than the basic price of the structural frame. Composite columns are likely to nd an increasing role in supporting the very long-span oors which are becoming more usual in commercial constructions and in modern buildings. When comparative study of CFT, RCC and Steel building is done, CFT building is found to be better in load carrying capacity with small cross section of column and displacement parameter Also number of stories for same structural system is more compared to RCC and Steel building.