New York Avenue Bridge
City officials in Washington, D.C., decided against replacing the New York Avenue Bridge after feedback and evaluations showed the project would require a large budget and long construction schedule. The bridge, in a heavily congested traffic corridor, spans a number of railroad tracks and required an innovative approach to rehabilitate it. The value-engineered solution consisted of renovating the superstructure and substructure and replacing the deck with precast concrete deck panels.
The bridge, comprising twin structures each with three lanes and a sidewalk, carries 87,000 vehicles each day over Amtrak, CSX Transportation, Washington Metropolitan Area Transit Authority, Marc, and VRE railroads. Both eastbound (five spans) and westbound (six spans) bridges consist of a twin steel-plate girder system with floor-beam-stringer framing. The structures are supported by gravity-wall abutments and single-column piers. They are continuous, with varying skew angles of 45 degrees at the west abutment and 70 degrees at the east abutment.
The rehab upgrade added redundancy to the two-girder superstructure with minimal impact to the railroads’ catenary systems, which attach to the existing bridge girders. The program also upgraded the existing deck and superstructure, repaired bridge piers and abutments, and completed other improvements. Two architectural dynamic gateway monuments were added at the approaches as well.
The design retrofitted and re-engaged the existing substructure and foundation units to support a new multi-girder superstructure system topped with precast concrete deck panels. The improvements to the superstructure were achieved by replacing the bearings and by erecting a new girder line between the existing twin girders, creating a multi-beam system with proper structural redundancy. The superstructure was supported on post-tensioned pier caps resting on the existing retrofitted pier columns.
The precast concrete deck panels, which were post-tensioned both longitudinally and transversely, cantilever nearly 13 feet over the exterior girders. The deck-replacement portion of the project also involved replacing traffic barriers, railings, median, fencing, lighting and fixtures, as well as shifting the deck’s expansion joints to the approaches to allow better preventive maintenance and serviceability.
Construction of the new superstructure and deck had to be coordinated with removal of the existing bridge deck and other components, along with erection of new girder lines. Extensive communication among all portions of the construction team was needed to coordinate the complicated construction sequence, which involved multiple stages.
The efforts paid off, as the design approach provided faster construction, elimination of delays due to formwork and concrete curing, facilitation of deck replacement, and minimized disruption to train activities.
“The successful rehabilitation of the New York Avenue Bridge utilized an innovative approach to minimize disruption from construction operations and to ensure that this structure will be able to accommodate the surface-transportation needs of this growing region for decades to come,” says Robert Radly, senior vice president and east region director for T. Y Line International, the project’s designer. “T.Y. Lin International is very pleased to have worked with the District of Columbia Department of Transportation, Fort Myer Construction Corp., and the Federal Highway Administration on such an important local project.”
The project satisfied all of the clients’ goals, providing a structure that facilitates all types of users (railroads, trucks, cars, and pedestrians) and accommodates anticipated local and regional expansion needs during the next 50 years.
It also impressed the judges of the 2014 Design Awards competition sponsored by the Precast/Prestressed Concrete Institute, who gave it the award for Best Transportation Special Solution.
Structural Precast Elements:
– 52,626 square feet of panels for westbound bridge; 4,652 square feet of panels for eastbound bridge.
– 66 panels used in westbound bridge, 56 panels used in eastbound bridge.
– Typical panel size of 8 feet wide by 49’10” long.
– Typical panel weight of 60 kips.