An advanced analytical procedure for a friction anchorseabed interaction problem is developed to numerically estimate the dynamic response of a friction anchor with an end bearing plate due to mooring force of floating structure. In this paper, the friction anchor and the end bearing anchor plate are assumed to be an elastic rod and a flexible or rigid circular plate, respectively. The seabed is assumed to be a fluid-saturated poroelastic medium whose behavior is governed by Biot's theory. The effects of the permeability of seabed, the radius and length of friction anchor on the dynamic response of it embedded in seabed are numerically investigated.
The pile anchor has been used for mooring of various floating structures on the sandy soil and the stiff clay soil. At the present time, the pile anchor is adopted for the various soils; and is installed by boring and grouting works, pouring works, and combination works. When the frictional resistance of the pile anchor is not to sufficient, it is installed by the boring and grouting works and/or the underreamer is attached to the end of pile. Takatani et al. (1991, 1993, 1994) have shown that the end bearing anchor plate is an excellent mooring structure in the weak soil for floating structures based on the investigation for the response of seabed around it. In these studies, the frictional force acting along the anchor-rod of end bearing anchor has been neglected since the radius of anchor rod is very small in comparison with the radius of end bearing anchor plate. However, the frictional force cannot be neglected in the structure of actual anchor rod. It may be necessary to consider the frictional force acting over the surface of anchor rod in" the anchor plate-seabed interaction analysis.
