Long High-level Temperature Effect Of Concrete-filled Steel Tube Structure

1 SummarizationAt present, super-length tall buildings are ever-increasing by popular. Expansion and contraction joint is not supposed to be located or at least frequently located in average buildings for the requirements of their functions. The longest space between two expansion and contraction joint, which is set in code for structural design is frequently exceeded in cast-in-place frame structure. Therefore, temperature problem is one of vitally important research topics in structure designing of super-length tall buildings. Now a series of temperature problems have been researched in our country and abroad. There are main two methods: one is problems are solved by dealing with construction, the other is problems are solved by calculating it. In this paper, the latter is adopted and CFSTC in structure is analyzed and studied.In this paper, bearing capacity of CFSTC is calculated and contrasted in three specifications in order to be referenced by designer. This paper makes use of Finite Element Method to study temperature problem of super-length tall building under several loading case and analyze several contrast model. Research fruit have been educed and some problems which need more research are found.2 Comparison of Calculation Methods for Bearing Capacity of CFSTCunder Eccentrically LoadingConcrete filled steel tubular columns are the keys to solve the problem of "stout column" in tall building. There is not much research about characteristics of concrete filled steel tubular in tall building in our national and abroad. In China, there are three specifications for calculating bearing capacity of CFSTC. According to the three specifications in this paper bearing capacity of CFSTC under eccentricity loading are calculated. The calculated results are compared and analyzed. The methods of calculation are briefly analyzed. The calculated results show that the difference of the calculated results by three calculation methods is rather big for short columns, but the difference of the calculated results is small at the large slenderness ratio. With eccentricity rations decrease, the difference of the calculated results increase. Now the difference of the theory and results of calculation is large in the threespecifications. The difference can result in difficulty in utility.3 The analysis of temperature effect of super-length tall buildingsFinite element analysis method is applied in temperature stress calculating problems of super-length tall buildings to make the integral temperature stress analysis in order to overcome the shortages of considerable errors resulted from the simplified hand-made calculating method in the past , and the lacks of structural integrality coming from the local calculations of each component and the other problems similarly involved. Also the modeling of the super-length tall buildings is provided .The whole structure of super-length tall buildings is chosen as an object of study, and a worldwide used large-scale structural analyzing program named Super SAP93 is also chosen to decentralize the structure into elements. The beams and columns of the structure are modeled as dimensional beam components, and the floor slabs and sheer walls are modeled as dimensional slab components. Then the practical integral structural analyzing models of the super-length tall building are made. The principles of the calculation of temperature distribution and the attained value of the difference in temperature are improved. The expression of calculating the horizontal difference in temperatures t is provided. The equation of the super-length tall buildings with the temperature distribution is formulated, and also the relevant solving strategies are provided.4 The analysis of temperature effect of true constructionIn this paper, "the second long-distance telecom hinge in Zhengzhou " is taken as an object of study, and a worldwide used large-scale structural analyzing program named Super SAP93 is also chosen to decentralize the structure into elements. This supe...