About this Project
The new $36 million urban arterial is a two-mile long, two-lane roadway. FST completed final design plans and specifications for the high-profile project.The structural work of the project includes three bridges and two retaining walls.
The existing Baldwin Street and Fairmount Street bridges carry local residential roads over the PanAm RR were comprised of timber, and the structurally deficient Baldwin Street bridge was a concern. The replacement bridges are two-span haunched steel plate-girder structures that cross over the PanAm Railway tracks as well as the new Broad Street Parkway. The tight geometric constraints of the proposed roadways and the RR clearances were a controlling aspect to the bridge configuration.The Baldwin Street bridge, which replaced a Red List bridge from the New Hampshire inventory is now open to traffic.
The three spans of the new 402-ft Nashua River bridge are comprised of steel plate girders and are supported on drilled shaft foundations. The bridge also features decorative approach treatments and end posts, ornamental lighting, and sidewalk overlooks and located above the river to make this structure a gateway to Nashua’s Mill Yard.
Two Mechanically Stabilized Earth (MSE) retaining walls up to 40 feet in height are used to support Broad Street Parkway near the Nashua River. A cantilevered sidewalk and moment slab system is used on one of the walls to minimize impacts to the river, and accommodations for existing and proposed utilities at the base of the walls were addressed.
Bid alternatives for aesthetic treatments were prepared for all three bridges to allow the City of Nashua to separately evaluate and include the enhancements in the construction contracts. The alternatives include aesthetical bridge rail and fencing options as well as concrete formliner finishes.
Owner: City of Nashua
Location: Nashua, New Hampshire
Highlights: Broad Street Parkway is the largest municipally managed project in the state of New Hampshire.