Dominion Energy launched its James River Crossing foundation upgrade project in May 2014 in Virginia. The utility has approximately 6600 miles of transmission lines, many located in and around waterways. When the line was built in 1968, Dominion Energy had used the best long-term alternative to corrosion prevention: marine-grade corrosion-resistant steel similar to ASTM A690.
In the early 1990s, Dominion covered a portion of the H-piles with a fiberglass jacket-epoxy grout encapsulation system to further protect them against the harsh marine environment. A compound also was applied to the remaining section of the H-piles in the splash zone. However, this compound did not provide adequate protection. This resulted in the H-piles corroding at the compound-coated areas and the encapsulation system jacket ends, causing the epoxy grout to begin de-bonding from the H-piles.
A structural upgrade of the H-piles was required to prevent foundation failure. The actual extent of the corrosion was not revealed until abrasive blast cleaning of the piles was performed. All foundations at the 18 tower locations were in far worse condition than the report indicated.
Following are images of the foundation upgrade project, which alleviated the need to build a new line. The images are featured in the August 2017 T&D World article, "Tower Foundations Get a New Life in Water." For a more in-depth explanation of the project, see the original article.