Experimental Research On Concrete Arch Bridge Strengthened By Prestressed Section Steel

With the increasing road traffic, some dangerous or old bridges gradually restrict thedevelopment of road traffic. Among them, the number of concrete arch bridges whichwere built in the1960s and1970s is the most. So the bridges’ strengthening and reforminginstead of demolition can achieve significant economic and social significance.Prestressed section steel strengthening method both has the characteristics of sectionenlargement method and external prestressing reinforcement method. With the function ofprestress, the section steel girders will undertake the internal forces burdening constantloads instead of arch ribs and bearing upper live load cooperatively with arch ribs. Thenthe purpose of reinforcing arch ribs would be achieved.Firstly, the process of reinforcement is simulated in the finite element method. Inorder to make comparison against laboratory experimental data, the arch bridge ismodeled in full accordance with laboratory model size, and the same material properties,boundary conditions and load steps. Secondly, other factors influencing the strengtheningeffect are researched in finite element method. These factors include the location ofcontact points, section steel girder bending stiffness and section steel girder compressivestiffness. Finally, the static load test of this method and the simulation test in the finiteelement method are compared to determine the effect of the reinforcement.According to the research, the frictional loss should be reduced during the pushingprocess. When the pushing process is completed, the section steel girder and the concretearch rib should be bonded effectively to form composite structure and work cooperatively.The axial force in the concrete arch rib is reduced effectively by this reinforcementmethod. And there is no new burden in pier (or abutment) during the reinforcementprocess.