An orthogonal component method for steel girder-concrete abutment connections in integral abutment bridges

Abstract

To predict the moment – rotation relationships of steel girder-concrete abutment connections with perfobond connectors, this paper develops an orthogonal component method, which is modified from the conventional component method. The connections were first disassembled into several horizontal and vertical components, and these components were simplified into translational springs. Next, the equations for the mechanical properties of each spring were determined with analytical analyses, and were calibrated against a number of numerical models. The springs were then reassembled and further simplified into two parallel rotational springs to calculate the rotational stiffness, the yield moment and the yield rotation of the girder-abutment connections. Finally, based on the Ramberg and Osgood model, the moment-rotation curves of the connections were determined, and were compared with numerical and experimental results. The results show that the proposed method is feasible to predict the rotational behavior of the girder-abutment connections, and can achieve fair accuracy in most cases when the shear deformation of concrete abutment is considered. The proposed method can also predict the shear force distribution among perfobond connectors. The main feature of the proposed method is that it can incorporate the contribution of perfobond connectors and vertical forces in the connections.