Study On Checking Method Of Bearing Capacity Of Arch Bridge Reinforced By Enlarging Section Area

With the development of economy and increase of vehicle in China, the bridge build in the 1950-1970s have had grievous disease. It became potential danger of transportation. Arch bridge occupy most part of these disease bridge. Due to the limit of funds and materals, to adopt the reinforcement measures which have advantage in less investment,shorter project period and can solve transportation problems is the most economical and applicable choice. Main arch ring is the most important load-bearing structure in arch bridge,also it is the emphasis of arch bridge reinforcement. The reinforced method by enlarging section area is one of the mose frequently method in arch ring reinforcement. In field of theoretical research,the study about ultimate bearing capacity of new arch ring after increasing section area is a problem that receives much concern.Until now, the main method about bearing capacity checking of reinforced arch ring by enlarging section area are allowable stress method,method mentioned in《Code far Design of Highway Masonry Bridges and culverts》and method mentioned in《Specifications for Strengthening Design of Highway Bridge》. The specifications we use now have turned into method of ultimate bearing capacity checking base on reliability theory. So allowable stress method no more applicable. And method mentioned in《Code far Design of Highway Masonry Bridges and culverts》applied only to state of no original stress. The method mentioned in《Specifications for Strengthening Design of Highway Bridge》solved ultimate bearing capacity checking about strengthening reinforced concrete compression member by enlarging section area. And it calculated the original stress skillfully. But it only aiming at reinforced concrete compression member not suitable for masonry arch bridges.This text will introduce how《Specifications for Strengthening Design of Highway Bridge》solved ultimate bearing capacity checking about reinforce on reinforced concrete compression member by increasing section area. Meanwhile, educed a suit of checking computations formulas fit for the masonry arch ring reinforcement by enlarging section area, using construction method of hanger-frame and bolt-spray. This checking computations base on ultimate bearing capacity checking about composite section in state of no original stress. Moreover, we use finite element software ANSYS to modelling and prove. This article replenished the content of《Specifications for Strengthening Design of Highway Bridge》.