The Study On Seismic Performance Of Top Story Frame Joints With Z-Shaped Column Subjected To Low-Cyclic Reversals

Z-shaped column is widely used in the structure of residential architecture in China, but currently, the researches on the behavors of Z-shaped column are insufficient. Based on the experiment study and finite analysis of shear behavors of top story frame joint with Z-shaped clumns, this dissertation reveals shear failure mechanism and discipline of top story frame joint with Z-shaped clumns for us. It also provides us with the design method which can be used in practical engineering.Firstly, According to experimental Study on top story joints in R.C. frame structure with Z-shaped column subjected to low-cyclic horizontal load, failure features, the shear capacity, ductility and hysteresis-loop characteristic were studied. The value of the shear capacity calculated by using the formula of L-shaped column joints in criterion was compared with the experimental data, which verified the formula. Secondly, based on the results of experiment, the nonlinear finite element calculation was carried out, a further study was accomplished on the effect of those influential parameters which contained concrete strength、stirrup reinforcement ratio and ratio of section height to section thickness of column leg. Conclusions can be drawn as following:the most important factor which affected seismic performance of top story frame joint with Z-shaped clumns was Beam diameter longitudinal reinforcement and depth of beam. Lastly, the calculation method about shear-resistant carrying capacity of top story frame joint with Z-shaped clumns was studied according to the experiment results and finite element numerical simulation results. The regression formula and the design formula were obtained from the experiment and numerical simulation results. Some suggestions respect to practical engineering were presented for the reference of structure designer.