海底电缆抛石保护层抗锚害能力的数值模拟研究

海底电缆抛石保护层抗锚害能力涉及到离散和连续两种不同尺度介质的相互作用。针对单独使用连续体法或离散元法分析的不足，首先通过经典变分原理，证明了离散-连续耦合算法的可行性。接着引入接触面的相容条件和平衡条件，实现了离散元法（DEM）和有限差分法（FDM）的耦合计算。设计了抛石保护层抗锚害能力的室内缩尺试验，采用与试验相同的工况，分别用DEM近似法和DEM-FDM耦合法进行了计算，并将两种数值算法的结果和试验值作了对比分析。结果表明，两种数值方法得到的结果都比试验值偏大，但是DEM-FDM耦合法更接近实际情况。

Numerical simulation study on the degree of submarine cable protection by riprap against anchor

The degree of submarine cable protection by riprap against anchor involves the interaction of discrete and continuous media of different scales. For the shortcomings of analysis only using continuum method or discrete element method, the feasibility of coupling algorithm was proved based on classical variational principle.Then, the coupling calculation of discrete element method(DEM) and finite difference method(FDM) was brought out by the compatibility conditions and equilibrium conditions on the contact surface. Indoor reduced scale experiment was designed,using the same conditions as the experiment,both DEM approximate method and DEM-FDM coupling method were used to numerical calculation. The results show that the calculation results of two kinds of numerical results are larger than that of experiment, while the results of DEM-FDM coupling method are more close to the actual situation.