Scope of Work

Cianbro is constructing the replacement of the Humpback Bridge over Boundary Channel, including the addition of an acceleration lane to alleviate traffic backups on existing ramps and the 14th Street Bridge in Washington, DC.

Project Details
Cianbro is:

• Removing the existing bridge
• Installing temporary cofferdams
• Installing 72 inch and 36 inch drilled shafts
• Installing pre-cast, post-tensioned concrete arch beams
• Constructing a pre-cast concrete arch tunnel
• Installing the substructure concrete and superstructure (high performance concrete) 
• Removing and reusing the existing granite cladding and stone veneer
• Installing storm drain structures and piping systems
• Placing lightweight, aggregate sub-base, which is part of the new pavement structure and surface with superpave asphalt concrete

Unique Challenge
The project, located in a major metropolitan area, requires all four lanes of existing traffic to be maintained at all times.  As a result, construction is being performed in five phases in order to successfully complete the project.