LARGE DEFORMATION NUMERICAL ANALYSIS ON THE EFFECT OF SPREADING ANGLE OF ANCHOR SHANK ON THE DIVING BEHAVIOR OF DRAG ANCHOR IN SAND

Drag anchors have been widely used as a mooring foundation with low cost and a simple structure. The installation and diving performance of the drag anchor is related to the anchor's weight, the thickness of the anchor fluke, the angle between the anchor shank and fluke, and the soil conditions. The influence of the geometric size of the anchor shank on the submersible performance of the drag anchor has not been studied deeply. A method to improve the diving performance of the drag anchor by adjusting the lateral angle of the anchor shank is proposed and verified by large deformation finite element analysis. Taking the installation process of MK5 drag anchor in sand as an example, the influence of different fluke-shank angle, lateral angle of anchor shank, anchor density, and anchor-soil interface friction characteristics on the diving depth of the drag anchor was analyzed. The results show that the embedded depth of the drag anchor shank is significantly improved when the shank is erect and leaned to the outside, compared with the traditional drag anchor with inwardly inclined anchor shank.