深中通道是一项标志性重大跨海通道工程,其混凝土结构的耐久性问题突出。深中通道所处区域的环境与港珠澳大桥类似,因此深中通道钢筋混凝土结构的耐久性设计采用了港珠澳大桥基于可靠度的耐久性设计方法,并利用港珠澳大桥暴露试验和工程施工数据,进一步对设计模型中氯离子扩散系数、保护层厚度安全裕度等参数进行了优化、修正。考虑到荷载对氯离子渗透率的影响,在深中通道耐久性设计中引入了荷载影响系数。根据以上模型和参数,计算得到100a设计保护年限的耐久性指标。针对工程施工、运营阶段可能出现的各种不确定性因素,根据深中通道的特点,提出了适合不同构件的附加防腐蚀措施,以提高其耐久性设计的安全裕度。

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.