Borough Road Bridge Replacement

Bristol/Hill, New Hampshire

The 38-ft closed spandrel concrete arch bridge carrying Borough Road over the Smith River had been placed on NHDOT’s Municipal Redlist due to structural deficiencies. DuBois & King performed a detailed inspection of the bridge and prepared recommendations. The recommendation report included options for replacing or rehabilitating the bridge, constructing a new bridge approximately one-half mile upstream, and abandoning the bridge completely. DuBois & King determined that repairs were not feasible, relocating or abandoning the bridge was not practical, and recommended replacement of the existing structure.

DuBois & King recommended replacing the bridge with a concrete deck and steel stringer superstructure supported by cast-in-place concrete abutments founded directly on ledge. The new bridge was located just downstream of the existing bridge to improve sight distances at the intersection of Borough Road and Smith River Road and so the existing bridge could be used to maintain traffic on Borough Road throughout construction.

D&K’s services for the project included bridge inspection, permitting, preparation of an engineering study, right-of-way plans, topographic field survey, utility coordination, preliminary design, final design, public meetings, bid phase services, geotechnical investigations (using a subconsultant), construction administration, and construction observation.