Anchors in sand bed: Delineation of rupture surface

Anchors of very large uplift capacities are required to support offshore structures at great water depths. The capacities of plate and mushroom type anchors are generally estimated based on the shape of rupture surface. An attempt has been made in the present investigation to delineate the rupture surfaces of anchors embedded in submerged and dry sand beds at various depths. The results exhibited two different modes of failure depending on the embedment ratio, namely, shallow and deep anchor behaviour. The load-displacement curves exhibited three- and two-phase behaviours for shallow and deep anchors, respectively. Negative pore water pressures recorded in submerged sand also exhibited variation similar to that of pullout load versus anchor displacement.