Study On Suspender Replacement For Concrete-filled Steel Tube Arch Bridge

Since the1990s, Concrete-filled steel tube tie bar arch bridge have developed rapidly,however the separation of Concrete-filled steel tube, tie bar relaxation, suspender rust andother diseases have found in a lot of this kind of bridges, which developing many studies forreinforcement technology for variety of diseases. Among those reinforcement technologies,suspender replacement reinforcement technology is the most complex and difficult. As moreand more such type of bridges enter into the reinforcement period, suspender reinforcementtechnology research becomes more and more urgent.In this paper, taking Sanshanxi Bridge reinforcement engineering as the background, tostudy several key problem of suspender replacement. The main studies are as fellow: Firstly,the election of suspender replacement system. By comparing the several previous suspenderreplacement system, grasping the characteristics and development trend of the suspenderreplacement system, this paper has selected a suspender replacement system which can bewidely used; Secondly, study of Suspender force identification. Through the analysis of thedevelopment status of Suspender force identification technology in the world, and comparingvarious simplified practical formula of suspender force calculation, this paper has selected aSuspender force identification method which can be used to widely, and especially for shortsuspender. And it has been proved by the field experimentation; Thirdly, the design of thesuspender replacement program. By calculating the cable tension classification and steplength of suspender replacement process, and analysing the contrast of different classificationand step length, this paper sums up the key points of safe control in suspender replacementconstruction; Fourthly, the optimization of suspender replacement process. Cable tensionoptimization is a calculation of different control objectives, which makes the stress state ofbridge more reasonable and safe.Because of its clear stress state and simple structure, the replacement reinforcementmethods of suspender can keep simple and practical; In addition, under the action of forces,the suspender is a very important part of the bridge, so the hierarchical control and cabletension optimization must be taken into account in the suspender replacement process. Thesetwo aspects not only is the key to the safety control of suspender replacement process, butalso affect the operational life of the bridge. Therefore, the suspender replacement technologyhas important practical value and sense.