Specifications include, but are not limited to: The proposed replacement structure is a 26-foot span and 9-foot rise, 88-foot long, precast concrete box culvert. The box culvert shall have 1-foot tall precast headwalls and 2-foot deep toe walls at the inlet and outlet. The upstream and downstream ends of the culvert will be slope tapered at 1.75H:1V (horizontal:vertical). The box culvert invert will be embedded 3 feet into the streambed and 3 feet of special fill will be placed inside the bottom of the culvert to create a natural streambed. The box shall be placed on a 1-foot-thick leveling layer of Granular Borrow – Material for Underwater Backfill. The new box culvert will be located on a new horizontal alignment which shifts the centerline approximately 1-foot downstream. The proposed vertical alignment will raise the profile approximately 4-inches across the new bridge. Traffic will be maintained by one lane alternating one-way traffic on a temporary bridge located on the downstream side.
