Research On Mechanical Properties Of Steel Box Arch Bridge With Mesh Suspengders

In recent decades,Having the merits of large spanning capacity,small building height and economical structure and beautiful appearance,the down-supported steel box arch bridge has been widely used at home and abroad.However,It is less applied in mesh hangers in down-contained steel box arches.Compared with the straight suspension rod arrangement,the mesh hanger can reduce the bending moment and deflection of the arch rib of the steel box arch bridge and the steel longitudinal beam(The tie rod),and improve the overall rigidity of the steel box arch bridge.Mesh hangers for steel box arch bridges are relatively less applied at home and abroad.Based on the finite element analysis theory,The paper is in the background of the 90 m mesh hanger-type steel box arch bridge in the Yinghe River Bridge in Fuyang City,Anhui Province.The static and dynamic characteristics of the steel box arch bridge of the boom are analyzed,and the structural internal force variation,displacement variation and the dynamic characteristics and seismic performance analysis of the steel box arch bridge under different boom arrangements are discussed.Firstly,this paper probes into the development history and status of steel box arch bridge at home and abroad,as well as the research status of static and dynamic performance of the arch bridge at home and abroad,summarizes the existing problems,and further explores the related research status of the form of suspender.Secondly,the basic stiffness matrix of finite element analysis is introduced to introduce the finite element calculation theory of arch bridge,including arch bridge static calculation theory,arch bridge dynamic characteristic calculation theory and dynamic finite element theory and response spectrum theory.The space finite element model of 90 m mesh hanger steel box arch bridge is established by using the bridge finite element software MIDAS CIVIL.The static performance of the bridge under the condition of dead load combination,live load combination,temperature effect and the most unfavorable load combination is analyzed.And the static influence of the boom arrangement on the steel box arch bridge;the calculation results show that under the load combination of the steel box arch bridge,the arch rib is under compression,the steel longitudinal beam is in the tension state,and the steel box arch bridge is mainly deformed vertically.Mainly;the mesh hanger is arranged with a straight boom,which can redistribute the bending moment of the arch rib and reduce the pressure of the arch rib.Due to the redistribution of the internal force of the arch steel box,the structural force of the steel box arch bridge can be more uniform,thereby reducing the arch bridge displacement changes.Next,the finite element theory and response spectrum theory of the dynamic characteristics of the arch bridge come into use.The theories are condoucted to find the impact of the natural vibration characteristics of steel box arch bridge.The mesh boom arrangement has obviously improved the in-plane stiffness.Having compared the self-vibration characteristics of rigid steel boom and flexble boom to steel box arch brige,the former enhances the out-of-plane stiffness of steel box arch bridge.Finally,the seidmic having compared the self-vibration characteristics of rogid steel boom and flexible boom to steel box arch bridge,the former enhances the out-ofplane stiffness of steel box arch bridge.The results show that the mesh hanger steel box arch bridge is in the elastic working stage,and the direct suspension rod has better earthquake resistance.