In 1905 when the Roebling family determined that they needed to expand their steel-mill facilities, a new town was born.
Located in Florence Township, N.J., near the Delaware River and named after its founders, Roebling changed drastically since its beginnings as farmland. Considering the remote location and lack of housing required for the mill workers needed to work in the new Roebling Steel Plant, the family designed and developed the surrounding area to accommodate all of the needs, including housing, stores, banks, even a town square.
After the Roebling Steel Plant closed in 1981, the site was used for a variety of operations, including polymer reclamation operations, a storage site for insulating products and for refurbishing refrigerated trailers. Raw materials and waste products from these operations were stored or buried on several on-site locations. The abandoned buildings were filled with dust and asbestos, while the soil, rivers, creeks and groundwater in the surrounding area were contaminated with heavy metals and polycyclic aromatic hydrocarbons.
Meeting Priorities
As part of cleanup improvements, the abandoned steel railroad bridge at the Roebling Steel Plant crossing Crafts Creek needed to be converted into a roadway bridge or used as a temporary bridge that would be able to support vehicles up to 110,000 lb. The bridge would eventually be turned over to the township, so all design and construction would have to comply with the latest AASHTO specifications.
In October 2008, W.J. Castle P.E. & Associates P.C., an engineering firm located in Hainesport, N.J., was retained by WRS Infrastructure & Environment Inc. to perform an in-depth inspection of the bridge and determine the overall condition of the structure. Upon completion of the analysis, Castle determined that, with minor repairs, the original bridge substructure and steel superstructure could be utilized in the construction of the new bridge. Castle designed the new roadway bridge including the repair details.
The only defect found on the abutments that required a repair was a small void, which was fixed using standard epoxy concrete compound. In addition, an underwater spall/void was found and repaired by pumping concrete into the void from underwater using Hydro-Marine Construction Co. Inc.’s equipment and personnel.
The six 37-ft 3-in.-long steel stringers, which formerly supported the railroad, were closely spaced at the center of the concrete abutment with the fascia beams measuring approximately 8 ft 6 in. in their original configuration. However, the client required a minimum of 13-ft 6-in. clearance to accommodate the trucks that would be using the proposed bridge, therefore, the stringer spacing was expanded to approximately 13 ft 11 in. edge to edge of the fascia beams.
The original diaphragms and steel stringers were removed and the stringers cleaned prior to the repairs. Approximately 6 ft on both ends of the beams exhibited some section loss and corrosion in the webs and flanges. A 6-ft-long by 3?8-in.-thick steel bent plate was attached to both sides of the beam using high-strength bolts, reinforcing the deteriorated portions of the steel stringers.
Because of the different configuration of the beams and the deteriorated condition of the supporting steel, new diaphragms and bearing plates were required. Based upon limited maneuverability and space, a full-length bearing plate was installed on both abutments and anchored into the concrete a minimum of 6 in. deep. Also, because of the new configuration of the beams, portions of the cheekwalls were removed to accommodate the new bridge superstructure.
In lieu of traditional studs, channels were welded at 12-in. increments along the top flange of the steel stringers. When the stringers were set in their final position, the new C8x11.5 diaphragms were installed in front of both abutments. Deck pans 1½ in. thick were welded directly to the steel stringers between the spans. A ¼-in.-thick bent plate was installed along the top edges of the fascia beams as an edge for the concrete deck. An additional back plate was installed at the edge of the deck along the face of the abutment backwalls. Steel-guide-rail posts were spaced at 6 ft 3 in. and attached to the beams with a ½-in.-thick base plate and to the bridge at the ¼-in.-thick bent plate along the edge of the fascia beams.
All steel components of the bridge were covered in black shop paint with the exception of the galvanized guide rail. The 7-in.-high composite reinforced concrete deck was poured in place in less than one day.
Hydro-Marine performed all of the construction aspects of the project including all repairs, removal of the existing structure and installation of the new bridge structure. Removal of the existing structure began in November 2008. The deck was poured the first week in January 2009, and the bridge was open to traffic by Jan. 23, 2009.
The project cost a total of $170,000, including underwater inspection with repair to the abutment.
Information for this article was provided by The Castle Group, Hainesport, N.J.
