Superior Entry North Pier Repair | US Army Corps of Engineers | Duluth, MN

Project Data
​Owner: USACE Detroit District
Engineer: USACE Detroit District
Contract amount: $11,235,932.00
Category: Steel Sheet Pile, Structural Steel, Concrete, Breakwater Repair
Year Completed: 2021

Roen Salvage was awarded the contracted to repair the north pier Superior Entry into the Duluth-Superior harbor. The repair involved driving sheet pile ranging from 65 to 80 foot long on both sides of the existing concrete monolith pier. The total length of pier repaired was 1,145 feet. Trenches were cut in the existing pier to allow tie-rods to be run between the sheet pile walls.

The original design for the repair called for the void between the existing pier and the channel facing sheet pile to be filled with ballast stone and grouted. Roen provided a new design to fill the void with concrete as part of a value engineering proposal. The redesign allowed for a superior end product with a significant cost savings. The void to the sheet pile opposite the channel and the space over the top of the wales and tie rods were filled with ballast stone. A layer of 600 to 1,000 lb. scour stone was placed on the lakebed at the toe of the sheet walls for protection.
 
The project initially called for 935 foot of repair. However, due to the effectiveness of Roen’s operation an additional 110 feet was added to the contract as a second phase of work.