Specifications include, but are not limited to: The purpose of this Geotechnical Design Report is to present subsurface information and make geotechnical design and construction recommendations for the replacement of an existing large culvert (#46619) consisting of an approximately 72-foot long, 60-inch diameter corrugated metal pipe (CMP) on Route 157 in Mattawamkeag. The existing culvert is in poor condition. The culvert is located approximately 0.37 of a mile north of Jordan Mills Road as shown in the attached Location Map. Route 157 is a Highway Corridor Priority 3 road. The proposed replacement structure will be a 98-inch span by 75-inch rise by 100-foot long pipe arch culvert on a skew of approximately 19.5 degrees to the roadway centerline. The invert of the proposed culvert is approximately 13 feet below the existing road grade at the roadway centerline. The roadway embankment slopes at the proposed culvert inlet and outlet shall be no steeper than 2H:1V to protect against erosion.
