Bridges | Bean Rd over Baboosic Brook, Merrimack, NH | 2016

Bean Road over Baboosic Brook was a 21-foot span, corrugated metal pipe (CMP) arch that was severely deteriorated and on the NHDOT Municipal Redlist. On September 2, 2015, during a routine inspection, the NHDOT closed the bridge to all traffic due to its extremely poor condition. The project design was fast tracked due to inconvenience of traffic detour and school bus rerouting. The new replacement structure is a 67-foot span steel beam superstructure with integral abutments consisting of cast-in place concrete pile caps supported on steel H-piles.

The new bridge width is 30 feet curb-to-curb and features an exposed concrete deck reinforced with stainless steel rebar. Ancillary to the project was the replacement of an existing 12-inch diameter water main that was located immediately below the existing CMP and streambed. The new 12- inch water main was permanently relocated upstream of the new bridge and beneath the existing brook channel by utilizing horizontal directional drilling. The bridge replacement project was funded by the Town of Merrimack and the NHDOT Municipally-Managed Bridge Aid Program and was completed in August 2016.