Structural design for a concrete pontoon (451’ x 151’ x 14’) for a floating dry dock with a lifting capacity of approximately 9,000 tons. Longitudinally post-tensioned, the pontoon has a honeycombed interior structure with precast silos interconnected with fin walls in both directions and sandwiched between top deck and bottom slab. The top deck is structurally composite with precast planks and in-situ topping thus eliminating massive on-site formwork and shoring.
High strength normal-weight concrete was specified for structural performance and long-term durability. The prestressing forces keep concrete from cracking under service loads and also keep the transverse construction joints intact against water intrusion.
This structural system is highly redundant, robust & lightweight also suitable for other floating concrete structures such as barges and platforms.