High-span Continuous Rigid Frame Arch Bridge Combinedsteel Box Research On Reinforcement Technology

IIRigid frame arch bridge has been widely used in highway bridge because of its simpleand beautiful structure,simple construction and cost economy.Especially,it has obviousadvantages in highway bridge and soft ground bridge.Gansu Province in recent years alsobuilt a certain number of rigid frame arch bridge,which is representative of Dingxi CityYuntian Bridge,Baiyun City,hanging Taiwan bridge,Yongjing County,West Rivertwo-bedroom reinforced concrete rigid frame arch bridge.But because of its poor integrity,sothat the lack of lateral stability of the bridge,the current majority of such bridges have been inthe ranks of the bridge,so the significance of such bridge reinforcement extraordinary.There are many ways to strengthen the bridge reinforcement,this article focuses on steelbox reinforcement method.The basic theory of its development is the steel-concretecomposite beam,which is a new method combined with the advantages of two kinds ofreinforcing steel and reinforced cross section.It is necessary to anchor the steel plate on bothsides of the arch and the arch ribs and weld it into an H-shaped ferrule,and then weld a layerof steel plate at the lower edge to make it a closed steel box,thus forming a rib The overallstiffness of the beam and the carrying capacity of the beam,compared with the ordinarysticky steel and increased cross-section method,the steel box reinforced components of theoverall bending,shear performance has been significantly improved and the weight will notToo big.In this paper,the application of the steel box reinforcement method in the reinforcementof the rigid frame arch bridge is systematically studied in the background of Yunista Bridgewith S209 line.The main contents are as follows:(1)Based on the theory of steel-concrete composite beam and the theory ofelastic-plasticity,the bending and shear calculation of steel structure reinforced steel structureis analyzed and the corresponding theoretical formula is deduced.(2)The damage and its forming mechanism of Yuntian Bridge were investigated.Themain arch ribs were reinforced by steel box reinforcement method and combined withnumerical calculation and analysis.The reinforcement effect of the bridge was evaluated.(3)Based on the finite element model of ANSYS,the influence of the mechanicalmodel and the reinforcement effect on the main arch ribs is discussed through the theoreticalanalysis of the steel box reinforcement and the load loading process.(4)Finally,this paper evaluates the reinforcement effect of the reinforced bridge by thereliability theory.The results of this paper show that when the bending capacity of the bridge isinsufficient,the steel box reinforcement method has a good reinforcement effect,such asincreasing the stiffness of the arch and the bending and shearing capacity,effectively reducingthe reinforcement arch The deflection.It is feasible to calculate the bearing capacity of steelbox reinforced members with steel composite structure theory.So the reinforcement methodcan be vigorously promoted to this similar type of bridge.