Parameter Analysis of the Mechanical Performance of Hinged Hollow-Slab Bridges with Gate-Type Steel Bars at the Bottom Part of the Junction Surface

Abstract

The evolution of hinged joint structures in Chinese hinged hollow-slab bridges was summarized to study the mechanical performance of hinged joint structures in hinged hollow-slab bridges with gate-type steel bars. Parameter analysis was conducted with the nonlinear finite element method for a hollow-slab bridge with a span of 8 m. The failure mode of the hinged joint structure with different parameters, including crack-occurring load and crack distribution, was studied. Countermeasures to improve the hinged joint structure were also discussed. Results showed that adopting a gate-type steel bar at the bottom of the junction surface did not improve the crack-occurring load of the hinged joint, but the load of the full-length crack was improved, and the occurrence of vertical full-length cracks on the junction surface and longitudinal cracks on the hinged joint was delayed. Increasing the diameter of the gate-type steel bar did not enhance the crack-occurring load, the load of full-length cracks on the junction surface, and the final distribution of cracks. Enhancement of the concrete strength did not improve the mechanical property of hollow slab and the junction surface remarkably. By contrast, enhancement of the bond strength of the junction surface improved the crack-occurring load of the hinged joint and reduced the distribution of cracks. Three layouts of reinforcement in the hinged joint and increasing the diameter of the gate-type steel bar, as proposed in existing references, did not fundamentally improve the mechanical property of the junction surface.