Theoretical And Experimental Studies On Predicting The Service Life Of Subsea Tunnel Lining Structures

Nowadays, durability matter of reinforcement concrete structures becomes the hotspot in the field of structural engineering, and is paid more attention. Among these matters, the most important issue is service life prediction, which is the requirement of development of engineering construction, and has economic and engineering value significantly. Based on the engineering background of Xiangan Subsea Tunnel in Xiamen, service life of tunnel lining structures is calculated in this paper theoretically. Then, service life is predicted further through quick test in lab under the criterion of safe bearing capacity.1. Firstly, influencing factor and mechanism that affect durability of structures are investigated in this paper. Then, based on the engineering characteristics of subsea tunnels, chloride ions induced corrosion and concrete carbonization are ascertained as main factors that deteriorate the subsea tunnel lining structures and are given further analysis and studies particularly.2. Under the criterion of safe bearing capacity, theoretical system is established for predicting the service life of subsea tunnel lining structures. Then, this theory is used to calculate service life of Xiangan Subsea Tunnel lining structures factually.3. Diffusion coefficient of chloride ions is the key parameter that influences the fist period life of tunnel lining structures. In this paper, diffusion tests are designed under different force conditions, including tensile force, compressive force and unloading, in order to study the laws by which force state influence the diffusion capability of chloride ions in concrete. Then, the calculating value of diffusion coefficient for calculating the first period life of lining structures is attained.4. Through electrochemical quick corrosive test of reinforcing bar, the aim of predicting the long term life through quick test is achieved, and the rusting law of steel bars in test is analyzed further.5. After quick corrosive test, loading capacity test of eccentric short columns are implemented, in order to investigate the change law of bear capabilities of model with the corrosion time. At the same time, the law by which corrosion degree of steel...