Design And Computational Analysis Of Contact Surface During Rotation Construction Of Long-span Bridges

At present,China's transport industry is in the stage of rapid development,the total mileage and traffic network density increase year by year,making the number of overpass bridges rise rapidly.In this situation,the technology of bridge rotation construction has prominent advantages,which can be used safely and quickly without affecting the transportation task of the existing line.Therefore,rotation construction has broad application prospect as well as great research value.Rotating spherical hinge is the most important stressed component in the rotation system.However,the current research on the stress condition of the spherical hinge contact surface is not mature and sufficient enough,and there are relatively few relevant literatures.In view of this,based on the actual engineering of the(75+75)m Mao-Zhan railway overpass bridge,this thesis systematically analyzes the mechanical characteristics of the spherical hinge,puts forward the optimal design method of its contact surface and uses the finite element method for verification.The main work of this thesis is as follows:1.On the basis of literature consulting,review and summarize the development process and research status of rotating bridges at home and abroad.Establish the contact models of four kinds of asperities with different shapes to explore the relationship between concentrated load,contact stress,depth of penetration and RMS slope;2.Establish the rotation system model of Mao-Zhan railway overpass bridge using ABAQUS,including both conventional model(without PTFE plates)and real model(with PTFE plates).Then analyze the stress distribution pattern of the spherical hinge contact surface during rotation construction,which is compared with the theoretical solution to verify the correctness of the model.The calculation of the real model considering the sliding plates and the analysis of the stress condition during the rotation is one of the innovations of this thesis;3.On this basis,through formula derivation and combined with the knowledge of composite rigid surface,put forward simplified models of the conventional model and real model respectively,and then vertify their correctness;4.To improve the stress distribution of the spherical hinge contact surface and reduce the edge effect,based on the elastic half space theory,propose an optimial design method for the contact surface and vertify its optimization effect to provide reference for the design and manufacture of the spherical hinge.