Study On Durability Influencing Factors Of Subway Structure And Its Service Life Prediction

Contrasting with ground buildings and other underground buildings, study on its durability had special meanings for different locations, constructing techniques and using functions of subway structures. The depth of the subway structure buried was over 10m commonly. There is a high concentration of CO₂ in the subway station and plenty of underwater and poisonous ions in the soil. Because part of structure was built before digging, the hidden trouble, like the high porosity of concrete in the water, often exist. Otherwise, the subway will produce strong stray current, and all of those will speed the corrosion of reinforcement in the subway structures. The current research results showed that reinforcement corrosion could make the concrete crack and decrease the structure intensity, which was the most direct reason of influencing concrete structure durability.On the basis of the study on durability of the general building structure, the experimental results showed that stray current, concrete carbonization and penetration of chloride were three main influencing factors of subway structure through studying its environmental characteristics. Through analyzing the corrosion mechanism that the three main influencing factors affect on reinforcement respectively, the degree and law of each of the influencing factors on reinforcement was confirmed. Based on analyzing the change conditions of reinforcement corrosion and following concrete crack, the durability status of subway structure was confirmed and the forecast on the service life of subway structure was conducted, which could be used for the reference of subway design and construction.At first, the meaning of study on durability and research advance home and abroad was introduced in detail, and the research contents of the durability of concrete structure and the research thoughts were introduced too.Secondly, influencing factors of subway station and their effect mechanism were discussed. Stray current, carbonation and penetration of chloride were the main influencing factors, according to the difference of working environment and using...