Stability of artificial subaqueous slopes in sandy soils

在近海条件下建造人工海蚀坑时，应考虑到由于水动力作用（例如：G.流动、波浪、地震）。我们的研究项目的重点是在非粘性土壤（侵蚀，沉积，破裂故障，液化故障）的海底斜坡的几何形状的变化，由于表面波引起的超孔隙水压力，导致有效应力的减少，并在海底斜坡的情况下，斜坡的几何形状的变化取决于波长L，波高H，水深h和渗透性k的土壤。在我们的前期工作中，我们研究了这种过程的基础上耦合的线性波动理论和线性拟静力固结理论。在数值模拟的帮助下，我们解决了相应的方程也考虑材料非线性固结。在研究项目的范围内，实验和理论研究将得到验证。因此，在模型水道中的模型试验将在H、L、h和k的变化下进行。采用两种不同的离散化方法，即有限元法（包括CEL算法）和SPH法，模拟海底斜坡的变形重排过程。将根据经过验证的数值模型，模拟在选定的北海场地建造海上风电场地基的典型海底斜坡。

During the construction of artificial submarine pits under offshore conditions it should be considered that the long-term slope-inclination is less than onshore due to hydrodynamic actions (e. g. flow, waves, earthquakes). Our research project is focused on changes of geometry of submarine slopes in non-cohesive soils (erosion, sedimentation, breach failure, liquefaction failure) due to surface waves which cause excess pore water pressures leading to a reduction of effective stresses and in case of submarine slopes to changes of slope geometry depending on wave length L, wave height H, water depth h and permeability k of soil. During our preliminary work we investigated such processes based on the coupling of linear wave theory and linear quasi-static consolidation theory. With the help of numerical modelling we solved corresponding equations considering also materially nonlinear consolidation. Within the scope of the research project the experimental and theoretical investigations will be validated. Therefore model tests in a model channel will be carried out under variation of H, L, h, and k. Occurring rearrangement processes in the submarine slopes will be simulated using two different discretization methods, namely FEM including a CEL algorithm, as well as SPH. The construction of a typical submarine slope for foundation of an offshore wind park at a chosen North Sea site will be simulated based on validated numerical models.