Bridges | Depot Street over Relief Arch, Antrim, NH | 2013
This 12-foot concrete arch bridge is one of three bridges on Depot Street that pass through the floodplain of the Contoocook River. It serves as a flood relief structure when the river overflows its banks. Constructed in 1914, it is considered historically significant and is eligible for listing on the National Historic Register. Rehabilitation involved the installation of a cast-in-place concrete slab with stainless steel reinforcement. The slab spans over the arch with its haunched ends bearing on geosynthetically reinforced soil to minimize vehicular loads carried by the existing arch bridge.
New curbs were installed to protect the existing parapets from vehicular impact and limit water intrusion between the slab and parapet. Existing cracks and spalls were repaired and new flared precast concrete modular (PCM) wingwalls, colored to match the historic arch structure, were installed to allow guardrail installation. This project was funded by the Town of Antrim and the NHDOT through the Municipally Managed Bridge Aid Program.