Jones River.

Complex Substructure Rehabilitation Over An Active Waterway 

Project Overview 

This project involved the rehabilitation of severely deteriorated bridge pier walls located over an active body of water. The substructure elements were in critical condition and required extensive structural repairs, concrete restoration, and protective coating application to extend the service life of the bridge. 

Due to the bridge’s configuration and the condition of the pier walls, access to the work areas presented one of the most significant challenges of the project. The only viable solution required the design and installation of a highly specialized staging and access system, enabling crews to safely reach the underside of the bridge and surrounding pier structures. 

The project was completed over approximately 18 months. 

Key Challenges 

1. Limited Access & Complex Staging 

The pier walls were located beneath the bridge deck and above water, making traditional access methods impractical. To safely reach the repair areas, the team engineered and constructed an extensive staging system beneath the bridge. This system provides stable work platforms while accommodating tidal changes, water movement, and structural constraints. 

In addition to suspended staging: 

• Barges and boats were used for material transport and crew access. 

• A custom-built ramp system was constructed from the highway above to provide controlled access beneath the bridge. 

• Crews worked both from below (on platforms and barges) and from above (on the roadway deck). 

The combination of marine access and elevated pumping operations required careful coordination and daily planning. 

2. Environmental Protection 

Working over water introduced strict environmental controls. No debris, demolition materials, dust, slurry, or contaminants could enter the waterway at any time. 

Environmental protection measures included: 

• Fully contained work platforms 

• Debris capture systems 

• Controlled demolition techniques 

• Continuous housekeeping and monitoring 

Maintaining environmental compliance while performing heavy structural repairs demanded constant oversight and disciplined execution from the entire team. 

3. Structural Rehabilitation & Concrete Placement 

Once access was established, crews began extensive substructure rehabilitation. The work included excavation of deteriorated concrete from the pier walls using controlled removal methods from suspended platforms. 

One of the most technically demanding aspects of the project was the placement of 188 cubic yards of concrete into forms located beneath the bridge. 

Concrete was: 

• Poured from the highway above 

• Pumped vertically and horizontally into forms below 

• Placed with precision in confined, hard-to-access areas 

Maintaining proper flow, consolidation, and finish quality in this configuration requires experienced operators and continuous communication between crews above and below the structure. 

4. Protective Coating Application 

After structural repairs were completed, the team applied protective coatings to 16,205 square feet of pier wall surface area. This system was critical to protecting the rehabilitated substructure from future moisture intrusion, chloride penetration, and freeze-thaw deterioration. 

Surface preparation and coating applications were executed from staging over water, requiring strict containment and quality control to ensure both performance and environmental compliance. 

Workforce & Coordination 

While a dedicated core crew of 8–9 skilled professionals led daily operations, a total of 58 individuals contributed to the project over its 1.5-year duration. The rotating workforce included specialists in: 

• Marine access and staging 

• Concrete rehabilitation 

• Forming and pumping operations 

• Coating application 

• Environmental compliance 

The success of the project relied heavily on coordination between disciplines, particularly during high-risk activities such as concrete pumping from above the deck to forms below. 

Results 

Despite complex access challenges, environmental constraints, and difficult working conditions, the project was successfully completed within approximately 18 months. 

The rehabilitation: 

• Restored structural integrity to severely deteriorated pier walls 

• Extended the service life of the bridge substructure 

• Protected the structure with a long-term coating system 

• Maintained environmental compliance throughout construction 

This project demonstrates the team’s ability to execute technically demanding substructure repairs in constrained, environmentally sensitive conditions while combining engineering ingenuity, disciplined field execution, and strong team coordination.