Abstract The stability evaluation of artificial submarine slope under wave load is a primary concern in the construction of offshore structures such as submarine pipelines and immersed tunnels. Aiming at this issue, an integrated Finite Element Method (FEM) model of wave-seabed interaction is proposed to investigate the effects of wave action on the wave-induced slope stability of the temporary trench. The Reynolds-Averaged Navier-Stokes (RANS) equations are adopted to describe the wave motion in the fluid domain, while the seabed domain is described using the Mohr-Coulomb constitutive model. The wave-induced seepage pressure near the slope is determined by Darcy's law and considered as an external load in the analysis. The stability of the temporary slope is evaluated by the means of shear strength reduction. The present numerical model is firstly validated through the comparison with the analytical solution and the experimental data available in the literature. The integrated numerical model is then applied to a practical engineering application, including a new evaluation method of stability for the trench slope excavated temporarily for the fully-buried submarine pipelines at an actual site. The results indicate that the stability of submarine slope is closely related to the dynamic wave pressure from the upper seawater. The minimum of FOS (factor of safety) corresponding to the most dangerous situation is introduced as the stability index for the slope with specific slope ratio in the whole process of dynamic wave loading. Additionally, the wave-induced seepage pressure should be considered as external load in the design for the seabed with large permeability such as sandy soils.

中文翻译：

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波浪荷载作用下人工海底边坡稳定性综合数值模型

摘要 波浪荷载作用下人工海底边坡的稳定性评价是海底管道、沉管等海上结构物建设中的首要问题。针对这个问题，提出了一种波浪-海底相互作用的综合有限元方法（FEM）模型，以研究波浪作用对临时海沟波浪致边坡稳定性的影响。流体域采用雷诺平均纳维-斯托克斯(RANS)方程描述波浪运动，而海底域采用Mohr-Coulomb本构模型描述。斜坡附近的波浪诱发渗流压力由达西定律确定，并在分析中被视为外部载荷。临时边坡的稳定性通过抗剪强度折减法来评价。通过与解析解和文献中可用的实验数据的比较，首先验证了当前的数值模型。然后将集成的数值模型应用于实际工程应用，包括在实际现场为全埋海底管道临时开挖的沟槽边坡稳定性评估新方法。结果表明，海底斜坡的稳定性与来自上层海水的动波压力密切相关。引入最危险情况对应的最小FOS（安全系数）作为具有特定坡度比的边坡在动波加载全过程中的稳定性指标。此外，