Work is under way on the $141 million “Route 52 Causeway, Contract A1, Bridge Replacement, Reconstruction and Resurfacing” project in Ocean City and Somers Point, N.J., in Atlantic and Cape May counties.
Plans for the 1.5-mi. (2.4 km) project call for reconstruction of Route 52, including construction of four new bridge spans, roadway construction including elimination of a round-about, and area improvements such as pedestrian walkways, fishing piers, and a new tourism facility, according to Chris Carter, senior project engineer of George Harms Construction Co. Inc., the project’s Farmingdale, N.J.-based general contractor.
“Route 52,” Carter explained, “links together Ocean City and Somers Point and extends over a series of barrier islands. The causeway is one of the few major highways, which feeds the ocean front beaches and bay front communities, which are favorite vacation spots.”
The existing Route 52 causeway includes two center low-level bridges, which span Elbow Channel and Rainbow Channel and two bascule bridges, which span Ship Channel and Beach Thorofare, which also is part of the Intracoastal Waterway.
Contract A1 includes replacement of the two center low-level bridges, construction of elevated on-grade roadway, and temporary ramps leading to and from the new center bridge spans. The existing center spans are outdated with four narrow 10-ft. (3 m) lanes — two northbound and two southbound lanes that are rapidly deteriorating.
The new bridge surfaces will be approximately 16 ft. (5 m) above the existing bridge surfaces, increasing the vertical clearance above the waterways to approximately11 ft. (3.4 m). The new elevated on-grade roadway is supported by precast concrete retaining walls, which is a system of interlocking concrete panels, complete with an architectural finish.
Contract A1 is divided into basically two stages. Stage 1 includes construction of the new northbound structures and temporary ramps. Once completed, traffic will be switched from the existing bridges to the two new completed spans.
In Stage 2, the existing structures will be demolished to clear the way for the adjacent southbound structure. Once shifted, the new northbound bridges will temporarily carry all four lanes of traffic, which will later be re-routed again in the following contracts.
In its final configuration, the northbound structure will include two 12-ft. (3.7 m) lanes and wide shoulders and the southbound structure also will include two 12-ft. lanes, wide shoulders, and a 10-ft. (3 m) wide pedestrian walkway, complete with several fishing “bumpouts.”
The project’s geotechnical aspects include pile-supported foundations, driven into dense sands. The precast piles are first jetted in place utilizing a series of Conmaco jet pumps, then driven to required capacity and tip elevations. Equipment for the driving operation includes Pileco D-160 and D-138 open-end diesel hammers.
The new elevated roadway is being constructed adjacent to the existing alignment in soft, unstable soils.
“To overcome the instability, the new embankment is supported on Vibro Concrete Shafts (VCSs) that are cast-in-place utilizing our Bauer BG-40 track-mounted drill rig. The machine is specially outfitted with a Vibro shaft head to plunge approximately 70 feet below existing grade. The shafts are tightly spaced and layout is tightly controlled with GPS survey instrumentation mounted to the machine,” Carter explained.
In other areas, embankment was designed with a surcharge embankment to consolidate the unstable subgrade. Lengthy “consolidation periods” were required to achieve the proper consolidation. This was a scheduling challenge to properly plan construction activities around the surcharged areas.
The new bridge substructures are pile supported on 30- and 24-in. (76 and 61 cm) square prestressed concrete piles, cast-in-place footings, columns and pier caps. The superstructure framing consists of 93.5-in. (237 cm) deep prestressed concrete girders, concrete deck panels, topped with cast-in-place concrete deck and parapets. Due to the harsh saltwater environment, the precast and cast-in-place elements are being cast using High Performance Concrete.
According to Carter, project challenges included the fabrication of the precast concrete piles, girders and deck panels. These structural elements are being fabricated by Baysore Concrete Products of Cape Charles, Va. Delivery of the product was by ocean-going barges that have been specifically designed and outfitted to carry and support the cargo.
Sea and weather conditions play a critical role in the departure of the barges. The 35- to 40-hour trip may easily be postponed for days due to adverse weather conditions, which can severely impact the progress of the project, he said.
The concrete piles and girders themselves are major challenges. Unloading and erecting these massive elements require the right equipment, rigging and preplanning. The girder weights are in excess of 180 kips (a kip is an abbreviation of 1,000 lbs.) and extend to approximately 138 ft. (42 m) in length. Weather factors such as windy conditions, which is the norm for any ocean and bayfront community, could easily halt or cancel scheduled crane operations, said Carter.
In addition to crane work, the wind also plays havoc with the water operations. Due to the close proximity of the ocean, the project area is highly affected by low and high tide. The tide variations are not always easily predicted based on the wind direction and speed. High and low tides can vary significantly, which can cause problems mobilizing water borne equipment throughout the project.
Traffic control and project access is a critical component that is consistently reviewed and implemented daily for the safety of the construction personnel and traveling public. There are minimal allowable lane closures by the owner during the peak construction season due to the heavy volume of tourism. Mobilization of equipment and materials around the project must be carefully planned. Materials are strategically staged around the project to optimize access.
“Prior to construction and during construction, we coordinate with the local police authorities to assist with traffic control and traffic safety. We have met with the Chamber of Commerce and municipality officials in both Somers Point and Ocean City in a cooperative effort to make them aware of the projects’s schedule and operations,” Carter said.
“We try to be friendly neighbors and minimize the impacts to local residents and commuters as much as possible. In addition, the project’s owner, the New Jersey Department of Transportation [NJDOT], has included traffic monitoring devices that are linked to traffic cameras mounted at various locations. ’Real time’ traffic reports are displayed on the electronic message boards warning the traveling public of any delays,” he explained.
With the exception of a few barges (material and transport barges), all equipment utilized for the project is owned by the general contractor. The technically advanced on-site fleet includes several cranes such as: a barge-mounted Manitowoc 4100 ringer crane, one Manitowoc 4100, two Manitowoc 2250s, two Manitowoc 777s, two Link-Belt 218s, two Grove and one Link-Belt rubber-tired cranes.
Earthmoving equipment includes several excavators, front-end loaders, and dozers from various manufacturers including: Caterpillar, Komatsu and John Deere.
There are multiple off-highway articulated dumps by Caterpillar and Komatsu. Two Putzmeister concrete pumps and Bidwell deck finishing machines support concrete operations while pile driving operations and sheeting involve Pileco open-ended diesel hammers and ICE vibratory hammers.
Flexi-float modular barges have been designed and pinned together as crane barges that are mobilized throughout the site with four twin screw custom-built push boats.
In addition to George Harms Construction, the development team includes: Michael Baker Jr. Inc. of Princeton, designer; DMJM Harris Inc. of Iselin, inspection consultant; and NJDOT of Trenton, owner.
Carter said the project is on a very aggressive schedule with a new northbound structured (Stage 1 completion) required in 22 months. The project began in June 2006 and final completion is scheduled for March 2010. CEG