Smart Risk Assessment Model of Water Inrush in Submarine Tunnel through AHP-TOPSIS and Intelligent Computing

In tunnel construction, water and mud inrush disasters are prone to occur when the tunnel traverses water-rich faults, which leads to structural damage and tunnel instability, which is one of the most severe hazards in tunnel excavation and construction. This paper proposes a method of combining AHP and TOPSIS. The weights are determined through the analytic hierarchy process utilizing expert scoring. The determined weights are evaluated and predicted by TOPSIS for water inrush risk. The Jiaozhou Bay Subsea Tunnel is used as a case to carry out the tunnel crossing the fault zone. Water inrush risk prediction provides a new idea for water inrush risk prediction.

Corrosion performance of a corrosion-resistant rail steel in the simulated subsea tunnel environment

The corrosion performance of a newly developed corrosion-resistant rail steel (U68CuCr) was investigated and compared with that of a normally used high-speed rail steel (U71MnG) by neutral salt spray tests, electrochemical tests, X-ray diffraction analyses, and the scanning vibrating electrode technique. It was found that the weight loss and corrosion rate of U68CuCr were lower than those of U71MnG under the same corrosion conditions. In addition, due to the influence of alloying elements (copper and chromium) in U68CuCr, the rust layer was thicker and denser, resulting in a stronger protective effect. Moreover, U68CuCr had a higher corrosion potential in electrochemical tests. Finally, the dynamic corrosion process of U68CuCr in 2.2% NaCl solution mainly followed a lateral extension of corrosion. Therefore, the corrosion resistance of U68CuCr was better than that of U71MnG in the subsea tunnel environment.