US 26: West Humbug Creek Bridge
OBEC designed and provided construction management and inspection for a new bridge on the heavily travelled Highway 26 over Humbug Creek. The existing bridge was founded on erodible mudstone that was being actively scoured by the creek. While the alignment and new structure would remain largely unchanged, the construction had to accommodate the near-constant traffic on this connection between the Oregon coast and the Willamette Valley.
To reduce impacts to traffic, the project was constructed using accelerated bridge construction (ABC). ABC was accommodated by stage constructing the piling and precast pile caps under weekday lane closures. Following completion of each foundation stage, the contractor implemented a five-day, single-lane closure for bridge removal and construction. This was repeated for each stage, minimizing traffic impacts.