This project featured the design of a hydraulically in-kind single span pre-cast, pre-stressed concrete plank bridge to replace the badly deteriorated two span steel bridge with foundations that were vulnerable to long term degradation scour of the bed of Braddock Run.  A review of available hydrological information and a generation of a hydraulic model was necessary to verify that the replacement structure was “hydraulically in-kind) as to generate the parameters needed for the scour assessment.

• This bridge was in a very congested location with intersections at either end of the bridge.  The footprint of the new bridge abutments had to be minimized so it was determined to found the new bridge on a caisson foundation supporting a pedestal abutment.
• To address scour issues, it was decided to place the new abutments behind the old bridge abutments and to leave the old abutments in place as a scour countermeasure.
• To avoid the disruption and expense of the drainage inlets and piping that a closed section on the bridge would require, Century developed an open bridge railing with a steel tube “hub rail” that allowed run off to drain over the sides of the bridge under the hub rail while providing the same traffic protection as a curb mounted open railing would provide.