Arch Combination Bridge Space Span Railroad Continuous Beam Analysis Of Mechanical Performance

Combined bridge of continuous girder and arch was emerging with our country's railway construction. It combines long span continuous girder with arc to form a combined structure, which has a better deformation resistant, wind resistant, earthquake resistant and fatigue resistant. Mature construction methods have been formed for this kind of bridges to consume less than other kinds of bridges whose span length were designed between 60m and 200m. Thus, combined bridge of continuous girder and arch is used more and more in our railway construction. According to finite element theory, This artile has made detailed analysis about Kunyang bridge, a combined bridge of continuous girder and arch which was still under construction on Wenzhou-Fuzhou rail way. This dissertation has mainly dealt with the following respects:1. It has introduced the derivation and current situation of combined structure of continuous girder and arch as well as mechanics characteristics and construction methods of this kind of bridge.2. Single beam and grillage simulation finite element model of Kunyang bridge was built to get the stress and deformation difference of construction stage and operating stage between side web and mid web. It shows that there is no obvious difference between web and mid web about direct stress, but the shearing stress of mid web is apparently higher than side web.3. There is no exactitude method to solve the lateral force of box girder yet. Our railway bridge designers solve lateral force by 1m width rigid frame with rigid restriction. In this dissertation, elastic restriction and additional displacement difference between side web and mid web rigid frame method was proposed to be compared with solid element model of the whole bridge as well as rigid restriction rigid frame method. And a important conclusion was finally drawn: lateral force could still be solved by rigid restriction for Kunyang bridge, however , for non-suspender sections, the result should be dicounted for non-suspender area; and for those transtrum at suspenders, we should chose a fit width of rigid frame for lateral force solution.4. The structure and mechanics behavior of the combine position of box beam and arch are very complicated, which makes it hard to know clearly about the stress distribution of the binding site of box beam and arch by theoretic solution. The binding site was divided into solid92 elements by a finite element software named Ansys to know the precise stress distribution, which may contribute a lot to the structure design and steel distribution design of the binding site of box girder and arch.