Application of Finite Element Method in Cathodic Protection Design for Immersed Tunnel Steel Structure

In order to solve the problem that the cathodic protection potential on the surface of immersed tunnel steel structure was difficult to calculate and test, the cathodic protection design of a project was optimized by numerical simulation technology. The accuracy of the simulation results was indirectly verified by the scale model. The results showed that for the immersed tunnel, the under-protected area usually appears at the bottom of the immersed tube because the sacrificial anode cannot be arranged at the bottom of the immersed tube steel shell. If the anode was evenly arranged on other surfaces except the bottom surface of the steel shell, the potential difference between the top or side of immersed tube steel shell and the bottom surface was 70-100 mV, and the bottom surface of steel shell was in an under-protected state. By increasing the number of sacrificial anodes on the side of immersed tube steel shell, the negative shift of the potential at the bottom of immersed tube was larger, and the protection effect of sacrificial anode was better.