Mechanical behavior of a novel steel-concrete joint for long-span arch bridges – Application to Yachi River Bridge.

• A novel steel-concrete joint is proposed for long-span high-speed railway arch bridges. • The joint combines the shear connectors, steel skeleton with outsourcing concrete and diaphragm. • A model test of the proposed SCJ specimen with a scale of 1/5 was conducted and investigated. • A nonlinear finite element model of the SCJ was established with high accuracy. • The experimental and numerical results indicated great mechanical properties of the SCJ. Steel-concrete joint is often used to connect steel and concrete structures in bridge engineering. In this paper, a novel steel-concrete joint, consisting of shear connectors, steel skeleton with outsourcing concrete and solid concrete diaphragm, is proposed for long-span high-speed railway arch bridges. The joint has the advantage of convenient construction and the concrete diaphragm at joint can ensure the smooth stress transmission of the arch. The mechanical behavior of the steel-concrete joint is investigated by conducting a down-scale model test with a scale of 1/5 under four loading cases. The stress distributions and crack patterns of the experimental specimen model are listed and analyzed. Then based on the experimental results, a nonlinear finite element model of the steel-concrete joint is established. Utilizing the local stress analysis of the model, the stress concentration near the concrete corner could be decreased by reducing the inclination size of corner. The results indicate that the proposed steel-concrete joint shows great mechanic properties, as well as reasonable force transfer behavior without damage during loading. The test and analysis of the joint are expected to develop the design of steel-concrete joints in arch bridges with complex structural composition. [ABSTRACT FROM AUTHOR]