Experimental Research Of The Concrete Filled Steel Tube Column Subjected To Axial Compress

Above all the situation of the research and the formula , involving that in abroad ,is introduced .And the paper gives us the constitutive relationships of the steel and core concrete and physical mechanical characters of them. For deriving the formula of the concrete filled steel tube short column subjected to axial compress we use the forth strength principle that is the shape energy ratio principle and get the formula when the steel gets into plastic stage. Through the analysis of theoretical study a unified strength criterion of concrete under triaxial loading conditions has been established .At last, according to the analysis of theoretical study we can get the limit bearing capacity formula of the concrete filled steel tube short column subjected to axial compress.As for the limit bearing capacity formula of the concrete filled steel tube long column subjected to axial compress , we lead to the tangent modulus and the conception of metal material .The high strength core concrete is divided into two kinds of situations: single axial loading conditions and triaxial loading conditions . At last, we can get the limit bearing capacity formula of concrete filled steel tube long column subjected to axial compress.On the basis of the theoretical analysis , twelve samples which have four kinds of long diameter ratio are studied experimentally. The parameters are measured respectively during the experimental process, such as bearing capacity , deformation , strain and so on. It concludes that when the other conditions is equal, the limit bearingcapacity of the concrete filled steel tube long column subjected to axial compress is reduced along with the long diameter ratio increased .In a word , we may get the result that the long column formula is fit for the limit bearing capacity calculation of the high strength core concrete filled steel tube long column subjected to axial compress.