Reinforcement Method Research Of Adding Hanger Rod To Tied-arch Bridge

Tied-arch Bridge with its concise and beautiful shape, low cost, poor geologicalrequirements and other characteristics, has been widely used in China. With the developmentof economy, highway traffic increases sharply, leading to some serious structural distress ofTied-arch Bridge. For the Tied-arch Bridge with rigid hangers at old times, the bridgedesigning could hardly consider of detection or replacing the hangers, so how to retrival thiskind of reinforced bridges becomes a significant problem.In this paper, the writer carries out researches and analysis of the rigid Tied-arch bridgein service, main dietressed problems of Tied-arch bridge were classified and the causes areanalyzed; through the finite element model of axial force, for the hanger rod in the impact ofdead-load and living-load shear and displacement analysis; under the impact of load,displacement and deformation will occur to the rib and the tie beam of Tied-arch bridge,generating additional internal force to the connection of the upper and lower end of the archhanger rod, arch rib and tie beam, and in long run, the accumulation of the additional internalforce will cause great damagement of the hanger rod; for the Rigid Tied-arch Bridgereinforcement, a method of positively adding hanger rod is proposed, by setting new hangerrod in the original one, whose load is partly bear and also increases the original pressure stressreserve,which finally leading to the balance of the overall coordination of the commoninternal stress state; with the characteristics of simply improving the bridge structure stress,conveniently constructed, and less impact on traffic. The characteristics, later in the process ofoperation, can be adjusted according to the need of replacing hanger rod. Based on thesupporting engineering projects, the finite element model is established via Midas, analyzingthe changes of internal forces of the main stress components before and after the structurereinforcement and the construction monitoring results are analyzed.The results show that the load-carrying of Rigid Hanger Rod has been improvedobviously, the stress-reserving for the original concrete hanger rod is also increased at thesame time, the cracks in concrete boom are eliminated, while the bridge load-bearing capacityand durability improved well, and reached a good reinforcement effect.