Hardesty & Hanover was the Engineer of Record for the new Flagler Memorial Bridge working with general contractor, PCL Constructors, Inc. The scope of the design-build project required replacement of the entire bridge off line with construction parallel to the existing bridge in order to maintain traffic for this busy causeway to Palm Beach.
The original Flagler Memorial Bridge was constructed in 1927 and is a 1,100-foot double leaf rolling lift span twin bridge that crossed over the 90 foot ICWW, connecting West Palm Beach and Palm Beach. Steel rolled beam approach spans flank each side of the draw span and carries two lanes of traffic in each direction with narrow sidewalks. The current bridge is functionally obsolete due to severe corrosion to structural members and the bridge width geometry does not allow safe passage for motorists, bicyclists and pedestrians.
The new design provides a rolling lift span over the widened 125-foot channel and prestressed concrete approach spans of 150 feet. The bridge superstructure has haunched girders to provide a continuous arch look. The lift span roadway deck utilized an exodermic concrete deck to minimize the dead load of the structure on the existing pivot pier. The operation of the lift span is a rack and pinion drive with variable frequency drive motor control and relay logic.
Community involvement requested that the new bridge commemorate their famous historic resident, Henry Flagler, and provide a traditional aesthetic appearance. The RFP had strict design requirements in regard to environmental mitigation, appearance and maintainability.