To protect two vulnerable locations from encroachment by the Chatanika River, RESPEC developed a design that used 1,000 feet of riprap revetment with launching aprons as part of seven resurfacing, restoration, and rehabilitation (3R) projects. The objective of these 3R projects was to rehabilitate and resurface 70 miles of the Steese Highway near Fairbanks, Alaska. Repairing the slope and embankment failures was an important component of these projects. Damaged and/or undersized culverts at six creek crossings were replaced with 10- to 12-foot, fish-passage culverts with headwalls at each end, riprap protection at the inlets, and stilling basins at the outlets. Repairs to settled abutment embankments, damaged pile caps, and washed-out riprap revetments were designed for six bridges. These simple, cost-effective erosion repairs have eliminated river- and creek-related maintenance and operations (M&O) efforts for the entire 70-mile corridor, despite several, near-design-level flood events having occurred since project completion.
Six of the seven project bids were slightly lower than the engineer’s estimate, and one project was within 10 percent above the estimated cost. The accuracy of these cost estimates helped the Alaska Department of Transportation & Public Facilities maximize the amount of work that could be completed with the available funds.