Research On Technical Condition Evaluation And Reinforcement Methods Of Concrete Rigid-framed Arch Bridges

Traffic volume increases with the economy and societydevelops rapidly.As a consequence,rigid-framed arch bridges built in last century cannot match the need of vehicle flow anymore.Rigid-framed arch bridges are congenitally deficient because they are lack of potential capacity. Research on technical condition evaluation and reinforcement methods of concrete rigid-framed arch bridges is meaningful.This paper based on Guangdong highway administration bureau science and technology project<Concrete rigid frame arch bridge reinforcement and reconstruction technology and applied research in in Guangzhou>, researched the diseases of Rigid-Framed arch bridge and the strengthen methods, main research contents and conclusions are:①The majority of the diseases appear on these parts of the rigid-framed arch bridge:slab with slightly curved bottom, middle of side chord, the joints, arch crown, skewback,bridge floor and tie beams.②As for the technical condition evaluation of the rigid-framed arch bridge,<Standars for Technical Condition Evaluation of Highway Bridges>is more pertinent than<Code for Maintenance of Highway Bridges and Culvers>.<Standars for Technical Condition Evaluation of Highway Bridges>suggests an elements division mode for the rigid-framed arch bridges. Theweight allocationsare proper and workable.The technical evaluation based on<Standars for Technical Condition Evaluation of Highway Bridges> could reflect the structural characteristicsof the rigid-framed arch bridges, making the technical evaluation reasonable and pertinent.<Standars for Technical Condition Evaluation of Highway Bridges>is suggested to use in the technical evalution of rigid-framed arch bridges.③The follows should be paid attention to in the reinforcement process of rigid-framed arch bridges:enhancing transverse stiffness and ensuring the effectiveness of structure stresses; limiting the overloaded vehicles to guarantee the operation safety of the bridges after the reinforcement; protecting the piers and abutments for the stress of skewback is sensitive to horizontal movement.④Based on a cross-comparison of reinforcement parts and reinforcement methods, the most proper reinforcement method for each part is determined. Chord member: sticking carbon fibre sheet or steel plate.Solid web section:section increasing method, sticking steel plate or sticking carbon bibre sheet.Tie pier:prestressing reinforcement method. Deck slab:sticking carbon bibre sheet or replacement.⑤The majority of the structural resistance bears the dead load of the structure, as a consequence, the live load bearing capacity decrease. The key parts bear heavy stresses and become weak parts of the whole structure. Attaching reinforced concrete to the solid web section could improve the bearing capacity more largely than sticking steel plate method.