Critical Underwater Concrete Retaining Wall Repair & Void Area Restoration

In response to flooding events impacting a creek running through their facility, Underwater Construction Corporation was contracted by a customer in Virginia to perform crucial underwater concrete retaining wall repairs. This project involved restoring the structural integrity of 850 feet of the 20-foot-high retaining wall foundation footers. UCC’s pre-mobilization diver and ROV video inspection also revealed large void areas behind the retaining wall, potentially causing loss of structural stability on the client’s plant operational deck area.

Due to the streambed, impacted areas beneath the retaining wall created void spaces varying from 1 foot to 8-foot-deep. UCC’s concrete retaining wall repair team developed a unique method of strategically placing and anchoring concrete grout forms with the various scoured areas beneath the unsupported wall footers.

UCC used a combination of various sized gabion rock baskets prepared with either sized super sack or field-customized geotextile grout bags secured within the baskets. The empty gabion basket-forms were flooded by the diver, anchored into the designated scour opening, and then filled with a 5,000 pounds/square inch concrete grout (4-inch to 6-inch slump) with retarder and anti-washout agents.

The lined gabion basket formwork was grout filled and permitted to initially harden. Using the diver pre-placed grout tremie fill pipes, UCC pumped a second custom grout mix containing an aggregate component and filled the large void areas behind the retaining wall.

All grout mixes and additives were blended at a local concrete plant and transported to the project site by 9 cubic yard transit mix trucks. The grout was discharged into the hopper of a concrete pump unit equipped with a telescoping placement boom that provided safe and effective underwater delivery to the set formwork.

A portion of the client’s creek area had been identified as a habitat for the Big Sandy Crawfish. Three times daily, under the permit granted by the client’s state regulatory agency, UCC secured pH and turbidity readings immediately upstream and downstream of the active project work zone.

Key to the protection of the client’s creek aquatic environment, UCC deployed a double turbidity curtain system along with the continuous pump out of turbid water within the curtained area. The high turbidity water was pumped directly to the plant’s 135-foot diameter stormwater clarifier for treatment prior to regulated discharge.

To complete the concrete retaining wall repair, an eight-person UCC dive team delivered over 835 cubic yards of custom grout material in 82 gabion basket forms, 557 feet of 3-foot diameter geotextile grout tube, and 600 feet of 2-foot geotextile grout tube that we resecured with over 2,400 feet of ½ inch diameter rebar anchors.

UCC has been a leader in underwater marine construction services, including concrete retaining wall repair, for decades. Our team’s extensive experience and expertise have made us a trusted partner for customers facing structural integrity challenges. By leveraging innovative techniques such as our gabion basket approach, we have consistently delivered exceptional results, helping to ensure the longevity and stability of retaining walls in various marine environments.

Don’t let compromised infrastructure hinder your operations – contact UCC today to learn more about our underwater construction and retaining wall repair services, and together we can safeguard your assets for years to come.

As one of the largest inland commercial diving services companies in the United States, Underwater Construction Corporation and its staff of over 200 divers, supervisors, and project managers operate from multiple regional locations in Connecticut, Maryland, Michigan, South Carolina, Tennessee, Texas, Wisconsin, and the United Kingdom. Through our global network of offices and associates, UCC has performed projects in over 25 countries. Every job, no matter the size, received the professionalism customers expect from UCC.

Reach out by filling out the short form on this page, or contact Darrell Moody, Sr. VP UCC-Southern Region at 423-504-4107 or [email protected] for concrete retaining wall repair, marine construction and underwater construction, infrastructure repairs, underwater coatings, and carbon wrapping services.