The Hibernia platform is located in the Jeanne d’Arc Basin, 200 miles east of St John’s, Newfoundland, in 260’ of water. The 500,000-ton gravity base structure (GBS) design consists of a 350-foot-diameter concrete caisson, constructed using high-strength concrete reinforced with steel rods and pre-stressed tendons.
Structurally, the 4.5-foot-thick icewall is supported by a system of X and V walls, which transmit the loads to the interior tiewall. The X and V walls have a thickness varying from 2-3ft and the tiewall has a thickness of 3ft. Put together, these walls form the icebelt. Gerwick patented this innovative design together with Mobil.
We also conducted a review and evaluation of costs versus productivity of reinforcement placement and concrete construction methods, such as jump forming and slip forming.
Throughout the project, we were a member of the Hibernia Expert Review Panel responsible for structural and construction review of the substructure for the Hibernia GBS Platform.