Investigation On Seismic Behavior Of Interval Concrete-filled Steel Tube Composite Shear Wall

With the increase of green environmental protection requirements in building and the development of construction industrialization in China,fabricated structures are widely used in various projects.At the same time,with the acceleration of urbanization in China,the land resources available for development in cities are limited,and there are more and more high-rise buildings,which puts forward higher requirements for the seismic performance of building structures.However,the ordinary fabricated concrete structures are difficult to meet the seismic requirements of high-rise buildings,and the fabricated steel structures have the disadvantages of high cost,large steel consumption,poor durability and fire resistance,inconvenient use and so on.In this paper,a new type of steel-concrete composite shear wall,interval concrete-filled steel tube composite shear wall,is developed,which has the advantages of convenient construction,flexible arrangement,less steel quantity,simple component making and so on.It has good economic benefits and engineering application value.In this paper,full-scale tests and numerically simulations are conducted to study the seismic performance of concrete-filled steel tube composite shear wall.The main work can be summarized as follows:(1)Three interval concrete-filled steel tube composite shear wall full-scale specimens were designed.The horizontal low-cycle repeated loading test was carried out on the composite shear wall specimens with different axial compression ratios.The failure characteristics and failure process of the composite shear walls were observed,and the failure mechanism of composite shear walls were analyzed.The effects of axial compression ratio on the seismic performance of composite shear wall such as hysteretic curve,skeleton curve,lateral bearing capacity,strength and stiffness degradation,deformation ductility and energy dissipation capacity were studied.(2)Based on the interval concrete-filled steel tube composite shear wall specimens,a reasonable numerical model was established by using the finite element software DIANA to study the seismic performance and failure mechanism of the composite shear wall.By comparing the results of the numerical simulation with the horizontal load-displacement hysteresis curves measured by the experiments,the differences of skeleton curve,stiffness degradation,side bearing capacity,deformation ductility and energy dissipation capacity were analyzed to verify the reliability of the numerical simulation.(3)Based on the established numerical model,the parameter sensitivity analysis of the composite shear wall was carried out.The influence of the number of steel tubes,the thickness of edge steel tubes,the size and spacing of batten plates on the seismic performances of composite shear wall,such as lateral bearing,capacity,stiffness,displacement ductility and energy dissipation capacity,were studied.The aforementioned work can provide the important theoretical basis for the design and the engineering application of the new type of composite shear wall.