Indian River Bridge

This new bridge carries the SR1 Coastal Highway across the Indian River Inlet in Delaware. The roadway includes four lanes of traffic with shoulders, a 12 ft (3.6 m) sidewalk and a sand bypass system. The bridge is divided into a 1,750-ft (533-m)-long cable-stayed span unit and 850-ft (259-m)-long approach spans. The cable-stayed main span is 950-ft (289-m)-long, providing a minimum horizontal clearance of 900 ft (274 m) for the Inlet. The required vertical clearance over the 200-ft (61-m)-wide navigation channel is 45 ft (14 m) with a maximum grade of 4% for the roadway profile.

The superstructure components include edge girders, floor beams, and a concrete slab. It is supported by two vertical planes of stay cables anchored in the edge girders. The stay cables are anchored in two vertical reinforced concrete pylons with steel beams connecting two opposite stay anchorages to resist tensions across the pylon section. The floor beams and edge girders are post-tensioned. Also, the top slab is post-tensioned longitudinally in the vicinity of the transition piers and the center portion of the main span.

The foundations for the main span unit consist of 36 in x 36 in (914 mm x 914 mm) prestressed piles. The cable-stayed spans are built on falsework over land and in cantilever with a traveling form for the portion of the main span located over water.

Owner: State of Delaware Department of Transportation
Design-Build Contractor: Skanska USA
Prime Consultants: DMJM Harris / AECOM
Bridge Design Consultant: International Bridge Technologies, Inc.