| Abstrakt: |
To research the impact of inner concrete filled steel tubular (CFST) on the reinforced concrete (RC) pier confined by stirrups, a Matlab program based on fiber model was written to calculate the moment-curvature (M-ϕ) relationship. The program was utilized to compute the M-ϕ relationships of three piers with same longitudinal bars and stirrups, and the three piers were an ordinary RC pier confined by stirrups、a high strength reinforced concrete (HSRC) pier confined by stirrups and a steel tube-reinforced concrete (ST-RC) pier respectively. The rules about bearing capacity of section and curvature ductility along with axial load N were deliberated by comparing the numeral results of three piers. The ratio of peak moment Mk to yield moment My was defined as super coefficient λs, and the disciplinarian of λs along with N was discussed. Participation factor ξ referred to the ratio of the moment provided by inner CFST to the total moment of ST-RC pier, and the laws of ξ affected by ϕ and N were researched. The results show that ST-RC pier has higher ductility and higher bearing capacity of section, and ductility decreases more slowly than other piers with the increase of N. λs of ST-RC pier is highest among three piers in most cases. On conditions of different N, ξ shows different variation trend with curvature ϕ up, and the maximum of participation factor ξmax is reckoned to be not affected by N basically. |
