As Engineer of Record, RK&K worked alongside the Delaware Department of Transportation (DelDOT), from development through construction engineering, to complete the Senator Margaret Rose Henry Bridge.
Named after Senator Margaret Rose Henry, the first African American woman elected to the Delaware State Senate, the new 470-foot multimodal bridge above the Christina River includes two 12-foot travel lanes and a separated 14-foot-wide bicycle/pedestrian path with more than 1.5 miles of new and improved roads, sidewalks, parking, and drainage.
Through specialized structural and geotechnical design and innovative engineering techniques, many of which were used for the first time in Delaware, the bridge ushered in a new era for the state’s Riverfront and opened the door to additional redevelopment and growth.
RK&K’s work began by advancing the project through the NEPA process, including enterprise architecture documentation; location and needs studies; evaluation of social, economic, and environmental impacts; field investigations; public workshops and individual stakeholder meetings; traffic analyses; alternatives analysis; environmental resource documentation; and cultural coordination. RK&K worked closely with the United States Coast Guard to identify issues related to the horizontal and vertical navigational clearances for existing and future boating needs. The team led the creative effort to document all stakeholder navigation concerns to develop the transportation needs for the crossing. Enhancements and new roadway connections were designed to alleviate traffic congestion and improve mobility and circulation for the Riverfront community by providing direct access to US 13 and I-495. As the project proceeded through DelDOT’s plan development process, the team developed final design and right-of-way plans, utility coordination, traffic control plans, and traffic signal and lighting design.
Through all this, the project team consistently considered the project’s most important goals: maintaining and enhancing outdoor amenities and incorporating pedestrian and bicycle facilities on the new bridge, direct and ADA connections to the East Coast Greenway, and 1.75 miles of shared-use path throughout the project limits. This project also involved public open space enhancements, pedestrian lighting and streetscaping, and a creative extension of the existing west bank Riverwalk through the bridge embankment via an underpass structure.
The team also met the project goals of a low-profile bridge, maintenance of river navigation, and incorporation of sea-level rise. The team successfully tackled these challenges by creating a structural design that incorporated potential sea-level rise and a roadway design that raised the profiles above the 10-year storm elevation, improving resilience and safety in the area.
A 30-foot-wide cast-in-place underpass supported on driven precast concrete piles was constructed, allowing the existing Riverwalk to continue through the bridge approach. The backfill between the abutment and the underpass is low-density, controlled low-strength material, which significantly reduces lateral pressure on the foundations.