Causes Analysis And Prevention Study On Cracks Of Urban Bridge

With the development of China's national transportation, the traffic volume has increased gradually and the vehicle loads have risen remarkably, which lead to numerous diseases of urban bridges during their operation periods, taking consideration of human and natural factors as well. Among those diseases, bridge crack is the most common one. Therefore, it is a vital measure to repair and reinforce urban bridges in disease and extend their service life for guaranteeing safe and smooth traffic and saving construction funds. Aiming the crack diseases of urban bridges, the relevant studies of the generation mechanism, the prevention measures and the reinforcement methods of the cracks of urban concrete bridges have been conducted in this paper.The generation causes of the cracks of urban concrete bridges have been discussed in detail, on the basis of which, the further research of the crack prevention technologies of urban bridges have been proceeded, including the technologies of crack repair, the principles of bridge reinforcement aiming at cracks and the relevant reinforcement methods, etc.The study of the reinforcement method of bridge cracks based on carbon fiber has been emphasized. The basic theory, the construction process and the computing method of carbon fiber reinforcement have been analyzed fully, offering reference of the practical application of technology in the reinforcement of urban bridges.Taking Guangfu River Bridge of Wutaizha Road in Jining for an example, the reinforcement method of urban bridges based on carbon fiber has been testified in engineering. From the results of bridge load tests before and after reinforcement, the effects of the carbon fiber reinforcement scheme were quite notable. It not only enhanced the global stiffness of the bridge structure, but also improved its dynamic properties, and most importantly restrained the extension of the original cracks of the bridge structure, extending its operation life.