Numerical Prediction of the Trajectory of Fluke Anchors in Sand

Abstract

The damage to submarine cable caused by the vessel anchoring has been constantly occurred, and the penetration depth of the anchor during vessel anchoring is a very important factor in the stability evaluation of the submarine cable. Clay seabed has undergone many studies in relation to anchor penetration. However the study of sand seabed is still insufficient. Therefore, this study presents a numerical model that can calculate the trajectory of the vessel anchor, the maximum penetration depth and the ultimate holding capacity in sand seabed, considering the static equilibrium relation of the force and moment acting on the anchor and the kinematic behavior of the lower surface of fluke. This study also developed a program (K-Sand) that can interpret the model with EXCEL VBA. Then the program (K-Sand) was verified with chart data on the Vryhof manual. The anchors of the Stevin Mk series were applied to the model verification, and the fluke shape of the anchors were converted to the square of the same area. As a result of the verification, the calculated values for the maximum penetration depth and the ultimate holding capacity data are within 10% of the chart data.