Construction Management and Construction Inspection
A68/NB-391 Bridge Replacement
THE PROJECT
The original NB-391 bridge was over 50 years old and deteriorating, and, with a width that limited shoulder areas, would not be able to accommodate the Commission’s future plans for the corridor. This design-build project involved the replacement of the NB-391 Bridge carrying turnpike traffic over SR 4018 (Main Street) and Trout Run on the Northeast Extension in Lehigh County.
Erdman Anthony was selected to provide design phase support, construction management, and construction inspection services.
FEATURES/SOLUTIONS
The existing three-span steel-girder/floor-beam structure was replaced with two three-span steel-plate girder bridges.
Roadway improvements included partial milling and full-depth reconstruction, widening to the ultimate six-lane width, significant earthwork, and a steel-pile retaining wall.
The project also included the installation of rain gardens, vegetated swales, and subsurface infiltration beds.
IMPACTS
The wider bridges increased total travel lanes from four to six with wider shoulders.
During stage 1, traffic was maintained on the existing bridge/alignment as the outside earthwork and the outside half of the structures were completed. The four lanes of traffic were then moved to the new outside structures. The old bridge was demolished in the middle, and the inside stage was constructed.
Throughout construction, the project team communicated regularly with residents of nearby Washington Township in the interest of their safety.
The project was substantially complete six weeks ahead of schedule.