Project Overview
When Bermuda was selected to host the 2017 America’s Cup yacht race, the Bermuda Royal Navy Dockyard required a new bulkhead to create a new quay wall within the basin for race staging and viewing. PND provided design and construction support for a 1,345-foot-long OPEN CELL SHEET PILETM (OCSPTM) bulkhead, which formed two of the four sides of the new nine-acre reclamation area in the South Basin, along with an existing concrete gravity breakwater.
PND’s OCSPTM bulkhead design provided substantial cost savings and a 40% reduction in the quantity of steel compared to a traditional tied-back, heavy-steel combiwall. The bulkhead was designed to retain dredge spoils primarily from Bermuda’s main shipping channel.
The seawall was constructed over a period of four months, completed in July 2016 in time to begin staging the America’s Cup. After completion, the face of the new quay wall was outfitted with mooring points and connections for floating docks, float piles, and gangways to access the vessels adjacent to the America’s Cup events village. After the event, the nearly 9 reclaimed acres continue to be a valuable resource for the dockyards area as additional waterfront property on the small, densely populated island nation.
Our Role
- Coastal Engineering: developed solutions to withstand severe storms, ensuring the bulkhead’s lasting durability.
- Waterfront Engineering: implemented a robust OCSPTM system well-suited for a variety of site conditions, including the weak soils and the shallow bedrock encountered at the Royal Navy Dockyards.
- Construction Support: provided design of temporary pile driving templates including on-site construction support such as evaluating changes in ground conditions and rapidly making design adjustments to maintain the design criteria and design intent while preserving the construction schedule.
Adaptable Design Withstands Extreme Forces
The OCSPTM system was designed to adapt to the variable geotechnical conditions and support the tall bulkhead height. The bulkhead is comprised of 36 sheet pile cells with a retained earth height that varies from 25 to 45 feet tall. The sheet piles were coated with a high-performance coating system and anodes to resist the highly corrosive saltwater environment. The top of the bulkhead was finished with a reinforced concrete cap.
In the final design, PND demonstrated that the system was adaptable to the varying site conditions, which included soft marine sediments and shallow bedrock. The design was also adapted to the owner’s provided backfill material, which was sourced from local dredge spoils and off-island quarry.
Several months after construction was completed, the eye of Hurricane Nicole—a Category 3 storm and Bermuda’s first major hurricane since 2003—made landfall across Bermuda, causing widespread damage. However, the OCSPTM system remained unharmed. Its resilience is a testament to the system’s strength and reliability in extreme conditions.
Saved
using PND’s OPEN CELLTM design
Cells
used to form the bulkhead
Berths
created
