The existing KY 874 Bridge over the Fork of Frederick's Ditch had failed and was closed to traffic. A complete replacement of the bridge, including the superstructure and substructure, was needed. Due to poor geotechnical conditions in the area, the proposed design seeks to replace the existing bridge with a geotechnically sound structure that could be constructed using local equipment within an efficient time frame. The initial intent of the project was to use some sort of precast solution for the bridge replacement for a proposal design format. After the project began, the Geotechnical Branch determined that the soils at the site did not present good bearing pressure and that a 3 sided precast structure would not work.
HMB briefly discussed a couple of different bridge options for replacement. HMB recommended that a 4-sided reinforced concrete box culvert be developed for design. Since the span is over 20 feet the structure is considered to be a bridge. A 4-sided slab top bridge was determined to be the best design option for design consideration and convention plan development. This alternative replaced the existing structure at the same location as the existing. The roadway alignment was to be shifted 4’ to the south to minimize impacts to an existing private bridge and sheet piling wall. A 5’ wide special ditch was reconstructed along the south west side of the road between KY 874 and an agricultural field. The bridge has a paved invert and minimum 24’ perpendicular width to convey the Fork of Frederick's Ditch.
Check out this local news article about the opening of the new bridge: http://union-webstercounty.14news.com/news/news/173753-ky-874-fredericks-ditch-bridge-opens-webster-county