During the last five years, a large number of suction caissons have been installed worldwide to support sub-sea facilities and to anchor floating facilities. For example, SPAR and semi-submersible hulls have been anchored to the seafloor using suction caissons, arranged in clusters of three to four caissons each, in water depths ranging from approximately 1,200 m to 1,800 m. During actual installation of suction caissons, unexpected problems may be encountered. This paper attempts to bridge the gap between the theoretical predictions and field observations by discussing the problems experienced and lessons learned by the authors during the installation of many suction caissons at sites in the Gulf of Mexico and offshore West Africa. The problems and lessons include effects of caisson penetration rate on the shear transfer between the soil and caisson interface, the importance of pump calibration and under-pressure correction, caisson tip bevel effects, rotation of the caisson during installation, field adjustment of target penetration, and the relationship between padeye depth and design robustness. Experience gained during these caisson installations1 is used to suggest improved suction caisson installation predictions and procedures.
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