胶州湾海底隧道二次衬砌混凝土的耐久性设计

Durability Design of Secondary Lining Concrete for the Qingdao Jiaozhou Bay Submarine Tunnel

通过对胶州湾海底隧道工程所在地的环境作用进行分析,以基于钢筋混凝土劣化模型的设计方法,对海底隧道衬砌混凝土的耐久性进行研究。结果表明,海底隧道要达到100 a使用年限,其海域段行车侧混凝土保护层厚度建议为60 mm加上适当施工偏差,其强度等级应取C50,氯离子扩散系数应取4×10-12m2/s。

In this paper, based on the design method of degradation model of reinforced concrete, the durability of secondary lining concrete for the Qingdao Jiaozhou Bay submarine turnel is studied by analyzing the environmental actions at the tunnel engineering site. It is shown from the analysis results that in order to achieve the submarine tunnel service life of 100 years, the side concrete coating thickness in the sea area tunnel section is recommended to be 60 mm and additional reasonable construction error, the concrete strength grade should be C50, and the chloride ion diffusion coefficient shall be taken as 4×10^-12 m^2/s.