Jersey Fresh: Conti Mends Aging Raritan River Span

Mon March 02, 2009 - Northeast Edition
Mary Reed




The current rehabilitation of the Garden State Parkway’s Alfred E. Driscoll Bridge across the Raritan River in New Jersey has its foundation in a cooperative operation involving the New Jersey Turnpike Authority (NJTA) and the Garden State Parkway (GPS).

Their agreement calls for construction of a new seven-lane bridge (completed two years ago parallel to the existing span) and rehabilitation of the original Driscoll Bridge.

The latter structure carries six lanes of the NJ Turnpike in each direction and the New Jersey Turnpike Authority estimates approximately 240,000 vehicles use it daily. About a quarter of these vehicles access the Turnpike from the bridge. According to the New Jersey governor’s office, studies have shown that Interchange 11 on the turnpike is the most common destination for drivers who cross the Driscoll Bridge.

Opened in the 1950s, the aging bridge has developed structural deficiency and functional obsolescence plus severe deck deterioration. Such was the state of the structure that holes have opened in the deck and concrete chunks fallen from it, while a number of load bearing members have become over-stressed to a significant degree. In addition, lane widths are narrow and vary from 10 to 11 ft. There are no shoulders and the configuration of the bridge’s approaches form an hourglass shape, increasing congestion.

The prime contractor for the rehabilitation of the Driscoll Bridge is Conti Enterprises Inc., a member of the Conti Group, headquartered in South Plainfield, N.J.

Begun in November 2006 with an estimated date of completion of May 2009, the approximately $100-million contract is funded by the New Jersey Turnpike Authority.

Rehabilitation will be carried out in several stages. There are two structures spanning the Raritan River, approximately 4,400 ft. (1,341 m) in length, which must be performed sequentially. Both bridges require similar treatment, in that Conti had to remove the existing concrete deck, rebuild the pedestals, jack the existing bridge to remove the existing bearings, repair the steel, then pour a new concrete deck. The northbound outer bridge was completed three weeks ahead of schedule in April 2008. The northbound inner bridge is scheduled to be completed in May 2009.

“About 70 percent of the job has been completed, and we are continuing deck removal and replacement,” Jay Price, executive vice president, business development, of the Conti Group said in early August. “We have approximately 150 craft and 15 office staff working on the job, plus subcontractors.”

The equipment fleet to complete the bridge deck demolition includes a Komatsu PC300 excavator with a slab crab bucket and a Komatsu PW170 excavator as well as a Komatsu WA420 wheel loader and Caterpillar 428 C and 430 D backhoes. The Bidwell 4840 concrete finishing machine and the Schwing 47-meter concrete pump from Pauline’s Concrete Pumping of Lakeville, Pa., with backup from a Conti-owned 38-meter Putzmeister concrete pump were used to pour more than 17,000 cu. yds. (12,997 cu m) of concrete supplied by American Redi-Mix Concrete Co. Inc. of South Plainfield, N.J., to place the deck.

Additionally, Conti purchased a Nelson Stud Welding 6000 machine to shoot dowels. This equipment is supported by a Terex RT 35 crane, an American crane, forklifts, compressors, light towers, man lifts, concrete saws, flatbed trailers, barges and a scow.

One piece of equipment on site was manufactured by Conti Enterprises Inc., because a gantry crane was needed to minimize the need for marine equipment.

“We designed and manufactured the crane with the help of an engineer,” Price said. “The crane is used to raise and lower our catch system, a platform used to catch debris and also to serve as a working platform for employees. This catch system also was designed and fabricated in-house, again with the help of an engineer.”

Subcontractors on the job include Cornell and Co. Inc. of Woodbury, N.J., which is handling steel work including girder jacking for bridge bearing replacement, bolster replacement, diaphragm replacement and new inspection catwalk installation. Their material, with the exception of the bridge bearings, was supplied by Lehigh Fab and Precast, a Conti Company, in Whitehall, Pa. J. & B. Welding Inc., headquartered in Coopersburg, Pa., is installing stay-in-place deck forms and sheer studs while Coastal Steel Construction of N.J., based in Princeton, N.J., is installing rebar, which will ultimately total more than 5 million lbs. (2,267,961 kg), supplied by JM Ahle Inc. of South River, N.J.

When the project is completed next spring the reconfiguration will result in the original two spans carrying eight lanes of northbound traffic while the new bridge will provide seven in the other direction. There will be shoulders on both structures. These new arrangements will increase the volume of traffic the crossing point can handle to approximately 300,000 vehicles a day.

Conti Enterprises Inc. is descended from a company founded in 1906 by the great-grandfather of current CEO Kurt Conti. With offices in Massachusetts, New Jersey, New York, Pennsylvania and Virginia, it offers clients civil and heavy construction services including design/build, construction management, infrastructure development, and general contracting as well as demolition and remediation projects.

Current projects include reconstruction of the Trenton-Morrisville bridge on Route 1, an $87 million project for the Delaware River Joint Toll Bridge Commission, construction of a new bridge for the New York State Department of Transportation (NYSDOT) in Chappaqua, N.Y. ($18 million), reconstruction of the Whitestone Bridge ($192 million) for MTA Bridges and Tunnels (Triborough Bridge and Tunnel Authority) as well as the rehabilitation of three rail bridges for N.J. Transit at Broad Street station in Newark, N.J., part of an overall $56 million station rehabilitation program.

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