Layout and Optimization of the External Prestressing Tendons of Hybrid Beam Rigid Frame Bridges

Abstract

External prestressing tendon systems can be set to alleviate the problem of excessive mid-span deflection of hybrid beam rigid frame bridges in the long-term use. Based on the Anhaiwan Bridge in Quanzhou of Fujian province, the effects of external prestressing tendons on reducing the deflection of the main span and improving the stress of concrete sections were studied by the shell- solid finite element models. Then the effects of the external prestressing tendons in the steel beams and the concrete beams were analyzed respectively. The effects of each prestressing tendon were further calculated. The final optimized layout was obtained by these studies, which can be used as a design reference for the external prestressed tendons of the hybrid beam rigid frame bridge. Finally, the deflection of the steel beam of the hybrid beam rigid frame bridge was analyzed under the impact of long-term effects such as shrinkage and creep. The comparative analysis of the different tensioning schemes for the external prestress tendons was carried out in order to provide a reference for the operation and maintenance management of the bridges.