Abstract:To enhance the post-earthquake functionality and structural repairability of bridge projects, a rocking self-centering double-column pier equipped with replaceable curved prestressing tendons and its structure and construction are proposed. Taking a municipal bridge project as the engineering background, the seismic performance objectives, design method and design process of the self-centering double-column pier were studied and determined. Based on the OpenSees platform, a numerical model of the rocking self-centering double-column pier was established to analyze the seismic capacity of the columns under the horizontal cyclic loading conditions at the top of the pier, and to verify the reasonableness of the key design parameters, such as the initial tensioning stress of prestressing tendons, the reinforcement rate, and the ratio of area of the energy dissipation devices, which were calculated based on the proposed direct displacement-based seismic design method. The results showed that the lateral stiffness and horizontal bearing capacity of the double-column pier were basically not reduced when the loading drift ratio at the top of the pier reaches 5%; the residual drift ratio after unloading was only 0.14%, which has excellent self-centering capability.The proposed rocking self-centering double-column pier structure and its seismic design method can realize the expected seismic performance objectives, and the reasonable design parameters of the structure can be obtained according to the method. The research in this paper can provide reference for the seismic design of municipal and highway bridges in high intensity areas.
