A series of centrifuge model tests on suction piles embedded in sand have been conducted to determine the horizontal, vertical and inclined loading capacities. The centrifuge model tests include as main variables the load inclination angle and the loading point. Test results indicate that the loading capacity of a suction pile with small load inclination angles in sand increases, reaches its peak, and then starts to decrease slightly as the point of load application moves downward. For larger load inclination angles, the loading capacity slightly but continuously increases as the mooring point moves downward. The maximum and minimum loading capacities occur when the applied loading is horizontal and vertical, respectively.
An innovative underwater permanent foundation system utilizing suction piles was introduced in the offshore industry in 1982 (Senpere and Auvergne, 1982). Since then, this new foundation system has been successfully used on numerous occasions for a variety of offshore structures in a wide range of environments due to its low cost, simplicity, efficiency, and reliability (Clukey and Morrison, 1996; Cottrill, 1992; Larsen, 1989). Suction piles have numerous advantages over conventional underwater foundation systems. The most significant advantages are: easy installation, large bearing capacity, and retrievability. Suction piles are installed through the application of reduced water pressure inside the pile. A suction pump attached at the top of the pile can accomplish the entire pile driving operation. Because of this efficient operation, very large suction piles can be driven into the soft seafloor, which eliminates the use of large numbers of small piles. As part of a study on the determination of the suction pile inclined loading capacity, a large number of centrifuge model tests have been conducted on a model suction pile embedded in sand.
