Reinforcement Design for Abutment-Beam Joint of an Integral Abutment Bridge Based on “Tensile Stress Region” Theory

An integral abutment bridge (IAB) is a type of bridge in which bearings and expansion joints are eliminated at the abutment. Its superstructure is usually connected to its substructure by casting the abutment-beam joint in-situ, which is responsible for transferring loads and reaction forces. Like the knee joint of the frame, the joint is in stress disturbed region and the reinforcement is more complicated. In this paper, based on the principle of equal stiffness, the whole structure is simplified to a “single girder + single pile” structure equivalently. Then combined with the “tensile stress region” theory, by calculating the element stresses of an engineering example under four load combinations, a simpler design method is proposed for the reinforcement of the joint of an IAB.