Analytical solutions on non-Darcy seepage of grouted and lined subsea tunnels under dynamic water levels

• Published in: Ocean engineering 2023-01, Vol.267, p.113276, Article 113276
• Main Authors: Liu, Xiang, Wang, Dongchi, Zhang, Yu, Jiang, Annan, Fang, Qian, Zhang, Rui
• Format: Article
• Language: English
• Subjects: Complex variable method; Dynamic water level; Grouting and lining; Non-Darcy seepage; Subsea tunnel
• ISSN: 0029-8018; 1873-5258
• DOI: 10.1016/j.oceaneng.2022.113276

For the grouted and lined subsea tunnels, the fluid in the low permeability media follows non-Darcy's law rather than Darcy's law. To address this, we provide analytical solutions for the grouted and lined subsea tunnel with dynamic water levels. Our method uses complex variable functions and Hansbo non-Darcy seepage model. The analytical solutions divide into three cases according to the critical water inflow and can degenerate into the traditional method following Darcy's law. The numerical simulation, experimental data, in-situ data, and other analytical solutions are adopted to verify our proposed method. The calculated results subjected to non-Darcy seepage are close to the in-situ data compared with other analytical solutions. When degenerating into the traditional method, the results agree well with those of previous methods following Darcy's law. It reveals that our method is suitable and universal. The parametric analyses of the non-linear flow index m, the critical hydraulic gradient il, the dynamic water level ξci, the thickness of lining zone tl, and the relative permeability coefficient ratio of the grouting zone and lining zone kg/kl are carried out. The results show that non-linear seepage parameters and dynamic water levels significantly affect the water inflow and water head. The denser grouting material can apportion more water heads and make the lining apportion fewer water heads to protect the lining from fluctuation influencing of dynamic water levels. •Fluid in grouting and lining zones follows Hansbo's non-Darcy seepage law rather than Darcy's.•Analytical solutions on seepage fields of grouted and lined subsea tunnels due to dynamic water levels are studied.•Three different cases of analytical solutions are divided according to critical water inflow and water level.•The concern on non-Darcy seepage of grouting and lining is needed, especially for dynamic water levels.