Numerical investigations of the effects of different design angles on the motion behaviour of drag anchors

The factors that may influence the motion behaviour of drag anchors include drag velocity, shape and density of the drag anchor, length of the anchor line, etc. This paper presents a coupled Eulerian-Lagrangian (CEL) model of both an anchor and its chains to simulate the installing processes of drag anchors. The comprehensive anchor behaviours including the variations of anchor trajectory, movement direction, drag angle and drag force at the shackle of drag anchors with various design angles are presented. The numerical results agree well with both existing FE results and theoretical solutions. Fitting equations describing the anchor motion behaviours are proposed. The effects of the values of the bearing capacity factor and the ratio between tangential and normal soil resistances of the anchor chains, when deriving theoretical solution of drag forces, are discussed. The influence of the friction coefficient of the chains is also analysed.