Bridge Replacement - Amicalola Creek & Afton Road - Dawson County, GA

Pond provided full design services for the replacement of an existing two-lane bridge in Dawson County which had been damaged due to severe erosion of the adjacent river bank. The project included demolition of the existing bridge and approach, construction of a new bridge and re-grading and paving of the approach to provide the required adjustments in the road grade to match the new bridge elevation.

The original bridge was a 160 foot long by 24 foot wide bridge consisting of pre-stressed concrete deck panels supported by bents spaced at 30 feet on center. The width of the new bridge was increased to 30 feet to provide adequate lane widths and the length was increased 20 feet, for a total length of 180 feet, to span over the eroded river bank. The bent spacing for the new bridge was increased to 60 feet on center to reduce the possibility of debris clogging the bridge substructure. The new bridge was designed for HS20-44 loading traffic loading. Due to increased span and bent spacing, AASHTO Type II pre-stressed concrete girders supporting a cast-in-place concrete deck was chosen for the new bridge superstructure. The bridge girders were supported by individual bents, consisting of five driven steel HP piles and a reinforced concrete pile cap. The exterior piles at each bent were battered to provide lateral load resistance.

Key elements of this project included:

• Design completion within a limited construction budget
• Designed and let for construction in 6 months
• Hydro study performed to ensure no flood plain encroachment