March, 2024 Luncheon

Speaker: David Ragan, P.E. and Nathan Wiggins, P.E.

Date: Thursday, March 21, 2024

Topic:  Perquimans River S Bridge Replacement

Presentation: Video

Summary: Stretching over the Perquimans River as it drains into the Albemarle Sound in northeastern North Carolina, a historic bridge connected the towns of Hertford and Winfall. Built in 1929, the previous structure carried a 0.6 mile long causeway of US17/NC37 on poor compressible soils including a 650 feet long bridge structure with a 161 feet Warren Truss Swing Span. Continued settlement of the causeway, flooding during severe weather, and deterioration of the structurally deficient Swing Span necessitated the replacement of the entire structure.

To replace the structure, NCDOT has embarked on its first movable bridge replacement through Design-Build procurement. McLean Contracting teamed with RK&K and Hardesty & Hanover to replace the existing structure with a new pile-supported bridge including 27 concrete approach spans and a new Steel Swing Span over the existing navigation channels for an overall length of 2700 feet. The approach spans consist of precast deck panel forms with a cast-in-place concrete deck pour, Florida I-beams, 30in. prestressed concrete piles and integral abutments. The Steel Swing Span consist of a stringer-floorbeam floor system with a lightweight concrete deck, and a Warren Truss.

Technical design requirements included strict adherence to durability requirements for concrete approach spans and concrete substructure, enhanced aesthetics of Swing Span and Control house, protection to turtle species, a new formulation for metallizing the Swing span structural steel, minimizing long-term machinery and electrical costs, and capabilities for remote operation of the bridge.