A spudcan is the term used for the base cones on mobile-drilling jack-up platform. The spudcans are the inverted cones mounted at the base of the jack-up which provide stability to lateral forces on the jack-up rig when deployed into ocean-bed systems.
Important calculations for spudcan design include the response to vertical, horizontal and torsional forces on the jack-up leg.
References
Spudcan Wikipedia(Text) CC BY-SA