砂质海床条件下海底电缆埋深研究

Research on the Burial Depth of Submarine Cable in Sandy Seabed

[目的]为了得到海底电缆在砂质海床条件下的安全埋深,确保海底电缆免受船锚威胁,给出了海砂海床条件下的船锚的安全埋深的建议。[方法]为了建议验证埋深的合理和安全性,依托于海南联网一回工程,通过对船锚在典型砂质海床中的拖锚全过程进行数值仿真,建立了典型霍尔锚部件的三维有限元模型,同时建立了基于有限元-光滑粒子流(FEM-SPH)的三维砂质海床土体数值模型。对拖锚全过程进行模拟,得到不同船锚在砂质海床中的拖拽曲线,并分析船锚质量以及砂质海床土体本构参数等因素对船锚贯入深度、船锚拖拽力的影响。[结果]仿真结果表明:不同土质的砂质海床条件下海缆埋深不宜小于0.35 m。[结论]利用研究成果,能为砂质海床条件下的海底电缆保护设计工作提供了理论依据和技术支撑,能够对砂质海床条件下海底电缆的埋设深度进行优化。

[Introduction]In order to obtain the safe burial depth of the submarine cable under the conditions of the sandy seabed and to ensure that the submarine cable is not threatened by the anchor,the safe burial depth of the anchor under the conditions of the sea sand seabed is given.[Method]In order to verify of the reasonableness and safety of the buried depth,based on the South China&Hainan power grid interconnection project I,the process of dragging anchor in sandy seabed was simulated,and the 3D finite element model of Hall’s anchor was established.The 3D sandy seabed numerical model based on Finite Element Method and Smooth Particle Hydrodynamics(FEM-SPH)was established.The process of dragging anchor was simulated and the drag curve of anchor in sandy seabed was obtained.The influence of mass of anchor,constitutive parameter and other factor to the penetration depth and drag force was analyzed.[Result]The simulation results show that the buried depth of the submarine cable should not be less than 0.35 m under the condition of sandy seabed with different soil quality.[Conclusion]Our results can provide theoretical basis and technical support for the design of submarine cable protection under sandy seabed conditions,and also can optimize the buried depth of submarine cables under sandy seabed conditions.