Shear Mechanism and Calculation Method of Steel Shear Key Dry Joint of Precast Segmental Bridge

Abstract:

Joints are the weak parts of segmental precast Bridges. To ensure the positioning and force transmission between segments， steel shear keyed joints are designed. To fully grasp the local shear performance of steel shear keyed joint， the shear mechanism and calculation method of steel shear keyed joint were deeply studied based on the existing experimental research results and theoretical analysis. The results showed that the steel shear keyed joint transmits the shear force between the joint by means of the contact pressure between the steel key and the concrete under the action of confining pressure， and the joint had high shear capacity and good ductility. Combined with the force transfer mechanism of steel shear keyed joint， a mechanical model was constructed， and the shear mechanism and failure mode of steel tenon joint were revealed， including shear failure of steel key、partial compression failure of concrete、tearing failure of concrete. Finally， the paper suggests that the shear failure of steel key should be used as the basis for the resistance design of steel shear keyed joints， and the strength of concrete around the steel key should be checked.