Seismic Test And Restoring Force Calculation Of Steel Fiber Reinforced High-Strength Concrete Shear Wall

As one of the main elements of high-rise buildings,shear wall plays an important role in resisting seismic loads as well as protecting the safeness of building structure,life and property of human beings.Reinforced concrete shear wall with low ductility and energy dissipation is unable to meet the needs of resisting seismic loads of high-rise buildings by only increasing its reinforcement ratio.In recent years,high strength concrete has been widely used for engineering,which further increased the brittleness of concrete and reduced the ductility of shear wall.As an original combined member,steel fiber reinforced high-strength concrete shear wall with concrete filled square steel tube columns(SFSW)was adopted to improve the ductility and carrying capacity of shear wall.Shear wall with the frame of concrete filled square steel tube columns and steel fiber reinforced concrete wallboard compounds the innovation of structure and material.In order to explore the seismic behavior of this original shear wall,the main contents in this thesis are as follows:(1)Crack development,failure characteristic,carrying capacity,hysteretic characteristics,energy dissipation,stiffness and ductility were measured by the experiments of the steel fiber reinforced high-strength concrete shear wall with concrete filled square steel tube columns under cyclic loading.Effects of volume fraction of steel fibers and concrete strength on the seismic behavior of shear walls were discussed.The results show that steel fibers used for shear wall can reduce the crack width and improve the cracking pattern.With the increase of the steel fiber volume fraction,the carrying capacity,ductility and energy dissipation capacity were dramatically enhanced,and the deterioration of strength and stiffness was delayed;With the increase of concrete strength,the carrying capacity was significantly increased and the energy dissipation was slightly improved.However,the ductility was reduced and the deterioration of strength and stiffness were accelerated.(2)Based on the test results and proposed calculation formulas for initial tangent stiffness and carrying capacity of shear wall specimens.The calculation formulas for yield load,yield displacement,peak displacement and ultimate displacement of shear wall specimens were developed.Also,trilinear skeleton model,calculation formula for unloading rigidity and restoring force model of SFSW were put forward.