Durability Design for Concrete Structure in Shenzhen-Zhongshan Brige

Shenzhen-Zhongshan Brige is a landmark important sea-crossing project. The durability problem of the project is prominent. The environment of Shenzhen-Zhongshan Brige is similar to that of Hong Kong Zhuhai-Macau Bridge. Thus, the durability design methods based on reliability theory used for Hong Kong Zhuhai-Macau Bridge were utilized for Shenzhen-Zhongshan Brige. And the parameters in the design model such as chloride diffusion coefficient and protective layer thickness safety margin were further revised according to the data obtained from the exposure test and engineering construction data of Hong Kong-Zhuhai-Macau Bridge. Considering the influence of load on the chloride penetration rate, load influence coefficient was introduced in the durability design of Shenzhen-Zhongshan Brige. Based on the model and parameters mentioned above, the durability index was determined to fulfill 100 a design service life. In view of all kinds of uncertain factors that might appear in the project construction and operation phaes may appear, additional corrosion protection methods for different structural members were proposed to enhance the safety margin of durability design.