Research On The Damage Evolution Law Of The Arch Bridge Suspender Steel Wire In Acid Rain Environment

In recent decades, the frequency of acid precipitation in our country is high, and the acid rain situation is very bad. The distribution area of acid rain in China is just the distribution area of long span arch bridge, and the service environment of long span CFST arch bridge in our country is acid rain. As one of the most important components of the arch bridge, the suspender is subjected to alternating load, such as the vehicle, and the external environment, so it is easy to damage. In recent years, the frequent accidents shows that suspender of the arch bridges have become one of the weakest links in the long span arch bridges. So it is very important to study the corrosion damage of steel wire in the arch bridge under the acid rain environment, and it is very necessary for reducing or even avoiding the accident of the arch bridge, and important for the reinforcement and maintenance of the arch bridge and the prediction of the remaining life. Firstly, through the investigation and the monitoring data of some arch bridges, common defects of the arch bridge cable component was showed and the causes were analyzed, the cable components common diseases were summarized in the paper. Then using artificial accelerated corrosion method, the arch bridge suspender wire corrosion test was done, the appearance of each stage of the corrosion of steel wire was described and analyzed by the weight loss method and surface roughness method to evaluate wire uniform corrosion and pitting. Arch wire uniform corrosion and pitting corrosion Depth prediction model with time was obtained. The experimental results show that the uniform corrosion depth at every moment in the corrosion process obey the lognormal distribution, and corrosion rate with time presents bilinear relation; pitting depth obey the obey the extreme star distribution, pitting with time presented linear variation. Finally, through the finite element analysis method, the steel wire with corrosion was discussed. The effect of the pitting depth and shape of pitting corrosion, and the uniform corrosion depth to the mechanical properties of steel wire were analyzed. The Results show that there was obvious stress concentration phenomenon on the bottom of the pitting corrosion in the presence of the wire, greatly reducing the wire limit bearing capacity; with the increase of the depth of pitting corrosion, the stress concentration phenomenon is more obvious; the wire limit bearing capacity is worse when the depth and lateral expansion coefficient become larger, in contrast, the limit bearing capacity is better when the longitudinal expansion coefficient become larger...