Experimental And Theory Research On The Nonlinear Performance Of Reinforced Concrete Tube In Tube Structure

Reinforced concrete tube in tube structure is a developing structure system of high-rise building. Two aspects are focused on: the test model study on static elastic property and simple analysis method for RC tube in tube structure, the pseudo-dynamic model test study and nonlinear analysis method for RC tube in tube structure.(1) The static elastic test of a 14 stories 1/10 scale reinforced concrete tube in tube structure model is accomplished. The influence of eccentric lateral load and top vertical load on property of structure model is emphatically studied, possessing certain reference value to analysis and design for tube in tube structure.(2) In this thesis, the storey deformations of frame-tube structures under lateral loads are divided into shear deformations and flexural deformations. The shear deformations and forces can be calculated by the simplified amendatory contraflexure point method, in which the shear stiffness of flange panels is taken into account for the first time. The flexural deformations and forces can be calculated by three methods. Firstly, the equivalent continuous system method can be used, in which the main influencing parameters of shear lag are discussed. Secondly, the flexural deformations and forces can be obtained by a simple method of assumed distributions of axial displacements, in which positive shear lag effects is included and influencing factors of displacement are discussed. Thirdly, a simple assumption is put forward that positive and negative shear lag are all exist in each storey of frame-tube structures under lateral loads. The assumed distributions of axial strains are given in the web and flange panels, in which the influencing factors of negative shear lag are discussed. Contrasting with space-frame analysis programs, the accuracy of the proposed methods is demonstrated through the analysis of framed-tube structures. The three methods are simple hand-calculation method and can be used for preliminary design.(3) The simple storey model analysis method is adopted to calculate tube in tube structure under lateral loads. Contrasting with the static test results shows that the presented method is reasonable. On the promise of analyzing the attached coefficient of out plane torsional stiffness for the bottom story of frame tube structure, the simple storey model method is put forward to analyze the tube in tube structure under torsional loads. the simplicity and accuracy of the proposed method is demonstrated through the analysis of the tube in tube structure under eccentric lateral loads.(4) The tube in tube structure model is equivalent as two degree of freedom system,...