Completed October, 2010
Location: Farmington, NH
Owner: Town of Farmington, NH
Engineer: Jacobs Engineering
This project involved replacing an existing cast in place jack arch bridge with a new precast bridge. The project allowed for the closure of the road entirely during construction. During the construction large boulders (the size of cars) were discovered within the excavation for the new, larger bridge. The Project included the bridge approaches and replacement of a reinforced concrete pipe within the eastern bridge approach. In addition to the originally contracted work there was additional roadway improvements added to the project to correct cracking and pavement deformation outside of the original scope of the work.
This bridge had been on the State of New Hampshire Red List due to structural deficiencies. Through the NH DOT State Bridge Aid program the project was 80% funded by the NH DOT. The project location on the Cocheco River (a NH DES Designated River) required particularly close attention to limiting soil laden water entering the river system.
Issue: With a large headwater (Waldron Mill Pond) upstream from the dam, dewatering was difficult. Solution: Installation of a “burrito” of crushed stone within non-woven fabric under the cast in place footings.