Study on the Influence of Nonlinear Seepage and Grouting Reinforcement on Surrounding Rock in Subsea Tunnel

He, X.; Zhou, X.; Xu, Y.; Ma, W., and Wu, T., 2020. Study on the influence of nonlinear seepage and grouting reinforcement on surrounding rock in subsea tunnel. In: Liu, X. and Zhao, L. (eds.), Today's Modern Coastal Society: Technical and Sociological Aspects of Coastal Research. Journal of Coastal Research, Special Issue No. 111, pp. 162–167. Coconut Creek (Florida), ISSN 0749-0208.Seepage is an important problem of tunneling engineering, which shows nonlinear characteristics in the low permeability media. Particularly in the seabed environment, Darcy's law is not accurate when considering the design of grouted subsea tunnels. Therefore, in this article, an analytical model considering nonlinear seepage and grouting reinforcement is established. Under a series of conditions, the analytical solutions of seepage fields and stress fields are derived and verified by numerical calculation. Then the influence of nonlinear seepage and grouting reinforcement on the pore pressure and effective stress of surrounding rock is investigated, and tunnel drainage is also discussed. The results indicate that tunnel excavation under nonlinear seepage is safer than that under linear Darcy's seepage, and grouting is a significant support that can not only improve the bearing capacity of surrounding rock, but also effectively reduce tunnel drainage.