Numerical Modeling of Wave-Induced Liquefaction Around Immersed Tunnel

One of the special design issues for the immersed tunnel is the stability problem of the structure under wave impact with significant wave height. A better understanding of the wave-seabed-structure interactions is essential for the evaluation of the stability of the seabed foundation under dynamic loading in the ocean environments. However, too much attention was paid on the characteristics of wave loading in most previous numerical models. Few investigations have been conducted for the cyclic behavior of the seabed deposits. In this study, based on Biot's partly dynamic poroelastic theory, a viscoelastic constitutive model in terms of Davidenkov backbone curve was used to describe nonlinear stress-strain hysteresis characteristic of the seabed soil. The pore pressure increasing pattern is modeled by Byrne pore pressure increment model, which was introduced as the wave-induced residual pore pressure source term, and implanted into Biot dynamic consolidation equation. Then, an effective stress analysis framework was established and used to analyze the dynamic response of a shallow buried immersed tunnel. The results indicate the high efficiency of the proposed analysis method to capture the complex wave-seabed-structure interaction and the relevant design issues are discussed as well.