Project Type: Structural and Seismic Design
Route 70 Over Manasquan River
Monmouth and Ocean Counties
Route 70 Bridge over the Manasquan River Bridge is considered a gateway to both Monmouth and Ocean Counties and serves vehicular, pedestrian and marine traffic. Constructed in 1936, the existing bridge is 625 feet long with a single leaf bascule span over a navigation channel. Due to the bridge's deteriorated condition and functional obsolescence, the NJDOT asked Arora and Associates, P.C. to design a replacement structure.
Arora performed an alternatives analysis and a vessel height survey to determine the best alignment for Route 70, height of the structure and the optimum structural solution for this site. Based on Arora's study, the roadway alignment was revised to minimize right-of-way impacts, the bridge height was set to provide a 25-foot vertical underclearance for marine traffic and the navigation channel opening was shifted and widened to 75 feet. The bridge will carry a 12-foot median, two 12-foot lanes and one 10-foot shoulder in each direction. Sidewalks and parapets are included on each side of the bridge resulting in an overall bridge width of 95 feet.
The twin eastbound and westbound structures will each be 724 feet long and consist of two three-span continuous superstructure units. The superstructure utilizes 8,000 psi AASHTO Bulb Tee Girders spaced at eight feet on center. Architecturally treated pier columns and caps will be constructed utilizing precast concrete components connected through post-tensioning. Pier foundations consisting of 24-inch concrete filled pipe piles will be constructed at the waterline within precast concrete cofferdam shells providing both driving templates for the concrete-filled pipe piles and architecturally treated formwork for the footings.
During September 2004, the bridge was designated as the September 11 Memorial Bridge in remembrance of the 170 people from Monmouth and Ocean Counties who died in the 911 terrorist attacks. The project scope was enhanced to include architectural treatments to the piers and parapets, monuments, signage, plantings and a Public Access Platform. The project also involves the widening and reconstruction of Route 70, a bridge fender system, noise walls, retaining walls, bulkheads, traffic signals, ramps, stormwater management water quality retention basins and manufactured treatment devices, highway lighting, ITS improvements and utility relocations. A project website was developed as part of Arora's Community Outreach Program Project. The project should be completed over a year ahead of schedule and at a cost of $52 million.