Suction caissons have proven to be economical and easy to install for anchoring deepwater offshore structures with taut or semi-taut moorings, such as FPSOs (Floating Production Storage Offloading), SPARs, FPSs (Floating Production Systems), etc. However, due to the complex loading conditions and paucity of model test database, the design of suction caissons is still in the state-of-the-art phase, and no industry consensus has been reached. Many important aspects and factors involved in suction caisson design, such as set-up effects, soil failure modes, padeye location optimization, axial capacities estimation, cyclic loading and sustained load effects, etc. are brought up for discussion. Limit equilibrium methods are used as an effective way to estimate suction caisson capacity and caisson penetration/removal parameters as well. Beam-column and Finite Element Analyses are more advanced methods to better understand caisson load-displacement behavior and verify load capacity derived from the limit equilibrium methods. Finally, suggestions for future research are given on how to clarify the uncertainties associated with current suction caisson designs.
Suction caisson foundations have proven to be an economical and reliable foundation alternative to conventional driven pile foundations, especially for deep water platforms, because of some advantages such as fixed location on seabed and simple installation procedures (Colliat et al., 2002). Suction caissons have been widely used for many types of offshore structures, such as jackets (Baerheim et al., 1995), tension leg platforms (Andersen et al., 1993), gravity based structures (Tjelta et al., 1990), deepwater subsea structures (Hefer, 1998), subsea well manifolds (Colliat et al., 2002), single buoy moorings (Senpere and Auvergne, 1982) and anchoring some deepwater submersible platforms (Dedani et al., 2002). For example, one recently successful suction caisson installation was completed for bp's Horn Mountain SPAR in Blocks 126/127, Mississippi Canyon Area, Gulf of Mexico (Audibert et al., 2003).
