Simplified model for upper bound method to analyze horizontal bearing capacity of torpedo anchors

The bearing capacity of torpedo anchors is the major concern for the marine industry. In this study, a simple model is proposed to calculate their horizontal bearing capacity based on the upper-bound limit analysis of plasticity. The horizontal bearing factor,$N_{\text{p,avg}}=f(s_u,L_{\text{f}}/D_{\text{w}})$, is obtained considering the influences of aspect ratio of torpedo anchor fluke($L_{\text{f}}/D_{\text{w}}$) and soil strength ($s_u$) by using the finite element method (FEM), and it is applied in the simple model. The analytic results of the simple model are verified through the comparative study with FEM and de’Sousa results. It is found that: (1) When the rotation center position is lower than the fluke of torpedo anchors, the rotation center position is close to the anchor tip by reducing fluke width or fluke length. (2) When the fluke length is larger than 1/2 length of torpedo anchors, compared with that by increasing the fluke length, the bearing capacity is obviously improved by increasing the fluke width. It is helpful for the optimization design of torpedo anchor shape.