Research On Cable Replacement Theory And Technology Of Cable-Stayed Bridge

In the past 50 years, about 300 cable-stayed bridges have been built in the whole world. Owing to the imperfect cable protection technology, cable corrosion is unavoidable after the bridge served a few years. In the world, a few cable-stayed bridges have to face the problem of being cables replaced. So, the engineering significance of cable replacement is great.The main objective of cable replacement design is to improve bridge geometry and internal forces of primary bridge by replacing cables. If failed to simulate the actual status of primary bridge in the design, which will result in the bridge geometry and cable forces differ desired value greatly after cable replacement work is finished. In this thesis, based on cable forces optimization theory, utilizing minimal remnant energy principle, the theory how to improve bridge shape and internal forces of primary bridge by replacing cables is founded. And in combination with cable replacement engineering of Sichuan Qianwei Bridge, based on the bridge elevation and cable forces measured before cable replacement started, using finite element software BSAS developed by Southwest Jiaotong University build analysis modeling, by means of cable forces adjustment and so on to make the cable forces of modeling approach the cable forces measured before cable replacement started, according to the scheme of primary design, aimed at cable replacement process, simulation analysis is done and get the calculated results. Compared with the primary design results, the calculated results in this thesis coincide better with the measured results after cable replacement is finished, which demonstrates that simulating the actual status of primary bridge accurately is very important to cable replacement design. Finally, construction techniques and crafts for cable replacement arc summed up and discussed.