| FRP (fiber reinforced plastics) was widely applied in building structure reinforcement for the outstanding advantages of lightweight and high strength. By extensive experiments and theoretical research of domestic and foreign scholars in recent years, both practical application and theory in the field have obtained some achievements. The study and application of beam, column, joint that reinforced by FRP was relatively mature. And some of seismic behavior research of these concrete members has been carried out, many engineering practice experience was accumulated. But there was not enough seismic behavior study about concrete frame joints and even the integral frame structure. According to reinforced concrete frame, based on seismic behavior experimental study of FRP reinforced beam-column joint, a further study about seismic behavior of the integral frame structure was developed in this paper. In order to have a comprehensive understanding of the reinforced concrete frame, laid a solid foundation for practical engineering application. The main research results and contents could be described as following three aspects:1. The new method and reinforcement principle of joint was summarized, based on the existing results of experimental study and theoretical analysis on FRP reinforced concrete members, seismic behavior experiment of plane frame side joint as conducted. Four specimens with same reinforcement and size was made by the team, with one of them didn't reinforced as a comparative specimen, the other ones reinforced with high strength GFRP and HFRP respectively through a reasonable and feasible reinforced method. The load carrying capacity, ductility, energy dissipation capacity of the specimens were compared and analyzed, the results showed that: satisfactory seismic behaviors could be obtained of the specimens reinforced by FRP, yield load and ultimate bearing capacity were improved evidently ; ductility coefficient of the FRP reinforced joints increased greatly, the ductility and energy dissipation capacity of the joints reinforced with FRP could be improved significantly; load-displacement curves of the reinforced specimens were spindle-shaped, and pumping contrasted with the reference joint, indicating that the FRP reinforced joints had a good seismic performance. 2. The seismic technological development of building structure was introduced simply. Principle and implementation steps of the pushover analysis method were studied, and advantages and disadvantages in application were researched. Comparative analysis showed that: as a performance-based seismic design method, pushover analysis of the structure can reflect the elastic-plastic performance compared with linear elastic analysis, and easier than dynamic time-history analysis, had a better practicability.3. Based on the experimental results of the joints, concrete frame models were established, and then pushover analysis of them was carried out through ATC-40 capacity spectrum method of SAP2000, the results showed that: the load carrying capacity and ductility of FRP reinforced concrete frame increased in different degree, showed different reinforcement efficiency with different reinforced system which almost in agreement with joint experimental results; the appearance sequence of plastic hinges was from beam to column, from bottom to top layer, from middle to side joints, which suggest that yielding mechanism of the FRP reinforced concrete frame is ductile; according to the analysis of pushover curves and target displacement, increased range of ductile is higher than the range of load capacity improvement. So, the thinking of study on seismic behavior of concrete frame structure based on FRP reinforced joint is feasible. Not only bearing capacity but also the ductile of building structures should satisfy seismic design requirement and seismic evaluation.
|
PDF Full Text Request