| Hybrid structure has become a main structure of high-rise building in our country, which has the following two advantages. Firstly, steel components, reinforced concrete components and steel-concrete components can be combined effectively. It not only has technical advantages of steel structures, but also has low cost characteristics of concrete. Secondly, hybrid structure has high stiffness, good fire-proof and good durability. Hence, hybrid structure system is a system for high-rise building that conforms to China’s national conditions, and it will have great development in the future.The methods of experimental study and numerical simulation were used in this paper. Firstly, the performance of steel reinforced concrete(SRC) column was investigated experimentally. The factors affecting on seismic behavior of SRC column were analyzed. Then, the model of SRC frame-reinforced concrete(RC) core tube structure was established. The mechanical behavior, distribution of hysteretic energy dissipation and reasonable damage model of structures subjected to earthquake actions were investigated. Specific content are as follows:An experimental investigation of 8 SRC specimen columns was carried out, which included 4 concrete-filled steel square tubular columns and 4 core steel reinforced concrete columns. All specimen columns were designed to have a same cross section of 250mm×250mm, steel ratio and so on. The variables of interest were loading path and forms of steel configuration. The performance of test specimens was discussed in terms of crack pattern, hysteretic response, stiffness degradation, shear strength reduction, ductility and energy dissipation capacity, as well as the strain of steel, longitudinal steel bars and stirrups. On basis of the test data and numerical results, effect of the axial compression ratio, cycle times, incremental displacement amplitude and variable axial force on seismic behavior of SRC columns was investigated.Based on elastic-plastic single degree of freedom(SDOF) system, effects of sites, hysteretic model, stiffness of the strengthening stage, damping ratio, intensity of ground motion on earthquake input energy spectrum(EIES) was investigated. The formula of EIES for elastic-plastic SDOF system was proposed. And elastic-plastic single particle with double degree of freedom(SPDDF) system was established based on two-dimensional yeild surface function. The effect of two axis period ratio on EIES was investigated for elastic-plastic SPDDF system. And the formula of EIES was proposed.Elastic and elastic-plastic time history was carried out for structures under single- and bi-directional earthquake actions. And force distribution of columns, beams, shear walls and coupling beams were investigated, as well as shear force and overturning moment of the structure section. Structural responses such as displacement, velocity and acceleration of the roof and story drift were investigated. And some conclusions were obtained, which will be helpful to the design of high-rise building.Elastic-plastic time history analysis of SRC frame-RC core tube structure was carried out under severe earthquake actions. The studies of proportion of each energy term in the structure were carried out. And the influence of characteristic of ground motion and dynamic characteristics on hysteretic energy was investigated. Computation equation of hysteretic energy dissipation for all components was proposed. And energy distributions for components were investigated in the structure height direction and horizontal direction.Taking the overall coefficient, axial deformation coefficient and stiffness characteristic value as the main design parameters for SRC frame-RC core tube structure, elastic-plastic time history and nonlinear incremental dynamic analysis were carried out for structures under bi-directional rare earthquake actions. Energy distribution and damage pattern of frame-core wall structures were studied. And reasonable damage pattern and the corresponding design advices were given. |
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