Repair of slope and embankment failures was an important component of these seven 3R projects, which rehabilitated and resurfaced a total of 70 miles of rural highway. To protect two vulnerable locations from encroachment by the Chatanika River, our design utilized 1,000 feet of riprap revetment with launching aprons. Damaged and/or undersized culverts at six creek crossings were replaced with 10- to 12 foot fish passage culverts complete with headwalls at each end, riprap protection at the inlets, and stilling basins at the outlets. At six bridges, we designed repairs for settled abutment embankments, damaged pile caps, and washed-out riprap. These simple, cost-effective erosion repairs have essentially eliminated river- and creek-related M&O efforts for the entire 70 mile corridor—even though several near-design-level flood events have occurred since these projects were constructed.
All but one of the seven projects bid for slightly less than our Engineer’s Estimate, and the other was less than 10% above. These accurate cost estimates helped the Department maximize the amount of work that could be accomplished using the available funds.
