Study On Mechanical Performance Of The Joint In The Mixed Steel-Concrete Arch Bridge

As one of the most important members, the steel-concrete joint connects the steel box and the concrete rib, which determines the safety and service performance of mixed steel-concrete arch bridge. So it is very important to study the mechanical performance of the joint in the mixed steel-concrete arch bridge.In this paper, the model test was performed for the reduced-scale joint specimen on the basis of the steel-concrete joint in the mixed arch bridge. The deformation and strain histories of the steel-concrete joint were monitored by bending experiment. Then the stress distribution and stress transfer law was analyzed, and the security of this joint was verified under the most disadvantageous load effect combination. The experimental data and the finite element simulation were further compared to verify the dependability of model test results. Based on the model test above, the security of actual steel-concrete joint was verified under the worst-case load combination by the finite element simulation and theoretical analysis. Then the parametrical analysis of the mechanical performance was performed, and optimum structures were proposed for the mixed steel-concrete joint at last.It is efficient to decrease the transverse deformation and main tensile and compressive stress by increasing the stirrup ratio of concrete structure, thickening the bearing plate, increasing the number of the rib stiffener and making the steel-concrete be adopted in the layout of concrete-filled double skin steel tube. They are also helpful for the high stress level in steel structure to transfer and disperse into the concrete with the low stress level.