Washington Aqueduct (3rd High Main)

The U.S. Army Corps of Engineers owns and operates the Washington Aqueduct – two water supply reservoirs serving the Nation’s capital. The 3rd High Main Bridge supports a 48” diameter water main over the Dalecarlia Reservoir providing a major water supply for the city.

In 2011, the aging bridge required extensive restoration of damaged bearings, pedestals, corbels, and the replacement of deteriorated pipe saddles that support the water main.

Location

Washington, DC
General Contractor

Freyssinet, Inc.
Owner/Designer

U.S. Army Corps of Engineers; Washington Aqueduct Division
Project Duration

June 2011-April 2012

Innovative Restoration with Flat Jack System

Upon receiving the restoration contract, Freyssinet identified several critical issues, including challenges with the geometry and installation of the “as designed” steel saddles. To address these problems, Freyssinet proposed a cast-in-place solution that incorporated an innovative Flat Jack System to lift and stabilize the water main during the process. The old saddles were then removed and replaced with new ones.

Also, a unique, custom-designed TFE sliding system that minimizes friction was used to interface between the water main and the new saddles. The saddles were then finished with Freyssinet’s Foreva® Relastic protective coating, adding an equivalent concrete cover of 1”, thereby extending the service life of the new saddles by 15 years.

Precision Bearing and Structural Upgrades

Freyssinet also carried out a comprehensive structural enhancement, replacing bearings, pedestals, and expansion joints at each pier while reinforcing the abutment support system with integrally cast-in-place structural steel frames. These frames also served as lifting points for bridge repairs, ensuring structural stability throughout the process.

Given the high sensitivity of the water main, all lifting operations were restricted to just 1/16″ and were meticulously monitored by an independent survey team. This highly delicate project required extreme precision, strict regulatory compliance, and careful execution to prevent any disruption to the city’s water service.

Freyssinet was thrilled to finish their work successfully in April 2012, and reliable potable water continued to be served safely to the District of Columbia, Arlington County and the City of Falls Church, VA

Bearings Maintenance

Freyssinet assists in inspecting and assessing damaged bearings and facilitates their replacement, ensuring restored traffic safety for both road operators and users.

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Bridge Repairs

Leveraging our strong client relationships and technical expertise, we have evolved into a leading solutions provider for bridge repair—often serving as the principal contractor on complex restoration projects. Today, we continue to set industry standards in bridge maintenance, rehabilitation, and long-term structural solutions.

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Bearings Maintenance

Freyssinet assists in inspecting and assessing damaged bearings and facilitates their replacement, ensuring restored traffic safety for both road operators and users.

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Bridge Repairs

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