NYCDDC Porpoise Bridge
AI provided NYCDDC with pre scoping services for the rehabilitation/replacement of the Porpoise Bridge, which carries Perimeter Road over Flushing River in Flushing Meadows–Corona Park, Queens, NY. Originally constructed in 1937 and rehabilitated in 1984, the bridge consists of 14 cast-in-place, reinforced concrete, rigid frames supported on reinforced concrete piers founded on a pile foundation. The structure is approximately 37 feet wide out-to-out and 370 feet in length with a bituminous concrete wearing surface.
A floodwater control structure is located under the north side of the bridge, which allows high tide and floodwaters to discharge into a tidal basin. The flood control structure consists of upper and lower tide gates with stoplog slots and a trash rack system. There are power-operated gates on the south side, which are used to control the water surface elevations.
The existing substructure consists of concrete piers, which are support on a raft foundation on piles. The rehabilitation of the structure will consist of complete superstructure replacement along with the replacement of the existing piers. The existing raft foundation will remain. The new superstructure will be widened to accommodate two 14’6” shared laws, resulting in a curb-to-curb width of 29’0”. A 7’0”-wide sidewalk will be constructed along the south side. The existing floodgates will be replaced.
AI was tasked with quantifying structural, geometric, hydraulic, safety, and functional deficiencies and developing targeted alternatives for bridge rehabilitation or replacement to rehabilitate the structure to good operating condition meeting NYCDDC's objectives. For this project, AI provided structural/bridge, civil, and traffic/transportation engineering; architectural services; electrical/lighting; survey; geotechnical engineering; environmental/hazmat; landscape architectural; tree consulting; and archeological services.
- Pre-scoping services
- Bridge design
- Quantifying structural, geometric, hydraulic, safety and functional deficiencies