Research On Mechanical Performance And Construction Technology Of Steel Box Basket-lifting Arch Bridge

Arch bridge is one of the basic bridge types commonly used in bridge design.At the same time,arch bridge in China has also been rapidly developed,there are a variety of arch bridge structure types,including concrete filled steel tube bridge,truss type composite arch bridge,arch beam composite system arch bridge.In this paper,a basket-type steel arch bridge is taken as the research background.The whole bridge model is established and analyzed by MIDAS CIVIL,a large finite element software,and the local analysis of the arch foot is conducted by MIDAS FEA,a general finite element software.The research content of this paper can be roughly summarized as the following points:The finite element model of the steel arch bridge under construction is established with finite element software,and the bridge response under constant load,vehicle load and temperature load is analyzed with emphasis.The local spatial model of the arch foot of the bridge was established with the finite element software,and the stress state of the arch foot under three kinds of adverse working conditions was analyzed in detail,so as to find out the weak point of the local area's stress and provide certain theoretical support for the design.The whole order for steel box girder installation "after the first beam arch",beam and arch erection of scaffold,respectively,the installation of steel box arch supporting system using the lattice type steel tube,bailey beam combination support system design should be combined with installation plan and structure characteristic,its support for basket steel box arch bridge calculation in every phases,first calculate the upper bracket,which in turn will lower part of the upper bracket as load calculation stents.The key work to ensure the one-time tension of the suspender is to determine the tension sequence of the suspender and the reasonable tension force of the suspender of the steel box basket-lifting arch bridge.In practice,the principle of stress-free state method is often used to calculate the optimal tension method.The determination of the optimal tension method not only considers whether the cable force is satisfied,but also integrates the influence of the tension process on the main beam and arch.In the process of suspender tension of tied arch bridge,the cable forces have greater influence on each other,while the displacements have less influence on each other.According to the characteristics of the bridge,the suspender tension force and construction technology of tied arch bridge are determined.