Influencing factors and shear capacity formula of single-keyed dry joints in segmental precast bridges under direct shear loading

Abstract

This article investigates the nonlinear behavior of single-keyed dry joints in segmental precast bridges under direct shear loading on the basis of nonlinear finite element analysis on lots of specimens with concrete plastic damage considered. Through detailed discussion on existing research, influence factors of the ultimate shear capacity of the keyed dry joint are analyzed, a new shear capacity formula was proposed and evaluated. The feasibility and correctness of the FE simulation method were verified by comparison with the existed experimental results. Concrete tensile strength at the key root is critical to the ultimate bearing capacity of the single-keyed dry joint under the direct shear loading. Friction on the joint interface and dimension parameters of the key do not have much effect on the ultimate shear capacity. However, reasonable key inclination (tan?) would be suggested as 0.7~0.9. In comparison with the predicted results obtained by other existed formulas, the proposed formula is demonstrated to be in perfect consistency with both tests and the FE simulation results.