By Joseph LoBuono, P.E., Roger Haight, P.E., ENV SP, M.ASCE, Chester Werts, P.E., S.E., P.ENG., Beth DeAngelo, P.E., and Christopher LaTuso, P.E.
When the Bayonne Bridge, which connects Bayonne, New Jersey, and Staten Island, New York, needed to be moved to make way for post Panamax ships, the Port Authority of New York and New Jersey implemented a novel solution.
The Port Authority of New York and New Jersey raised the roadway of the Bayonne Bridge 64 ft within the existing arch span. MATTHEW SPOTH, WSP
Since opening in November 1931, the Bayonne Bridge, owned by the Port Authority of New York and New Jersey (Port Authority), has served as an important connection for motorists traveling between Staten Island, New York, and Bayonne, New Jersey. But the connection it accommodates underneath its span has served an equally important purpose, providing ample clearance for vessels traveling through the Kill Van Kull waterway to the Port of New York and New Jersey.
Port Newark-Elizabeth Marine Terminal, in New Jersey, and Howland Hook Terminal, on Staten Island, are part of the largest container port network on the U.S.'s Eastern seaboard and the third largest in the Western Hemisphere. The port represents 30 percent of the commerce in the region, with more than $200 billion in cargo passing through each year. But the emergence of enormous post-Panamax cargo ships—and the 2016 expansion of the Panama Canal to accommodate these giant vessels, which has been a game changer in the movement of global goods—threatened the viability of the port as well as the future of the Bayonne Bridge. The limitations of the bridge risked causing a navigational bottleneck that would diminish access to the New York and New Jersey ports. A significant amount of shipping business would be lost to other East Coast ports of call, and in some instances, large container ships might have simply avoided trips to the Eastern seaboard altogether.
A space of 215 ft provides the necessary air draft clearance for the new generation of container ships carrying up to 18,500 TEUs (20 ft equivalent units, the standard measurement for shipping containers) to enter the ports. With the Bayonne Bridge topping out at a height of 151 ft, container ships were limited to those carrying 5,000—6,000 TEUs. The Port Authority faced the possibility that its historic bridge could be demolished and replaced to accommodate the larger ships. Fortunately, another solution emerged that was not only less disruptive to commuters and shippers but also preserved the historic bridge and those critical shipping lanes.
The original Bayonne Bridge opened in November 1931, and for 46 years it held the title of the largest steel arch bridge in the world, with a span of 1,675 ft. PORT OF AUTHORITY OF NEW YORK AND NEW JERSEY
The original bridge was designed in the late 1920s by Othmar Ammann, who would later serve as chief engineer of the Port Authority, with Cass Gilbert serving as architect. When Ammann designed the bridge, the shipping channel required a span of approximately 1,600 ft. Because of this, an arch truss bridge proved to be more cost-effective than a suspension bridge, so Ammann designed a steel arch truss with a suspended roadway floor system. For the approach structures, he chose twin steel edge girders that supported a floor beam, stringer, and concrete slab system. American Bridge Company was selected to build the bridge. One of the challenges for the construction of the bridge's main span was that it needed temporary shoring towers installed near the navigation channel, which today would most likely not be permitted because the Kill Van Kull needs to remain open for shipping.
When the bridge opened, it was the largest steel arch bridge in the world—a title it retained for 46 years. Even today, its 1,675 ft span across the Kill Van Kull ranks as one of the largest in the world for its class, accommodating 3.5 million vehicles every year. The significance of the Bayonne Bridge led to its designation as an ASCE historic civil engineering landmark in 1985.
The Bayonne Bridge Navigational Clearance Project, a $1.68-billion undertaking, began with a feasibility study that addressed and documented 41 options that were evaluated for technical feasibility, constructability, environmental impact, schedule, and cost to determine how best to accommodate larger container ships.
Two options that were given serious consideration—and ultimately rejected—were constructing a tunnel to replace the bridge and jacking up the existing bridge by 64 ft. However, tunnel construction would have required a lengthy environmental study that would have delayed construction, and it would have eliminated a national landmark. While jacking up the arch span would have preserved the historic bridge, it would have required an extended shutdown of vehicular traffic and disrupted navigational traffic, both of which were unacceptable economically. Other options that were considered and eventually rejected because of cost or operational difficulty included construction of a new bridge on a new alignment, building a lock and dam, and converting the existing bridge into a lift bridge over the suspended section.
Concrete segments for the approaches were built off-site to help alleviate the impact of construction on the surrounding communities. COURTESY OF HDR
After much consideration, the Port Authority chose to raise the roadway 64 ft within the existing arch span and build new approaches, while preserving navigational and vehicular traffic. The chosen option met the Port Authority's project objectives of preserving a historic landmark structure while maintaining economic viability throughout construction. However, such a complex project—raising the height of an existing bridge roadbed without removing the steel arch truss and keeping navigational and vehicular traffic flowing—had never been attempted before.
One concern when selecting the best solution was the proximity of the new construction to existing homes, businesses, schools, and houses of worship, with some of these structures being within 30 ft of the approach structure footprints. The reconstructed bridge maintains the existing alignment and right-of-way to avoid disturbing existing neighborhoods and the taking of land.
Segmental concrete construction was the chosen method for the approaches (essentially building them using concrete segments that were precast off-site) to help mitigate the impact of construction on the surrounding communities. The segments were transported on local streets from storage at Ports America in Bayonne. Half the segments were driven across the existing arch main span during construction. The size of the segments was dictated by the weight that could be transported across the existing structure.
Besides 215 ft of air draft at the centerline of the bridge, the Port Authority specified additional requirements that included:
- a 12 ft wide shared-use path for pedestrians and bicyclists
- lane-width expansion to 12 ft
- a median barrier and shoulders
- 100 years of serviceability
- improved entrance and exit ramp connections
- accommodations for future lightrail transit
The bridge is unique in that the steel arch span had sufficient strength to support two roadways at one time—the existing roadway, which was kept open for use, as well as the new roadway that was constructed 64 ft above it. This was possible because Ammann's design envisioned rail traffic, and the strength required for a rail system was built into the structure. However, rail service was never instituted, so the designers of the raised bridge used that reserve strength to support the two roadways simultaneously, thereby maintaining existing traffic during construction.
New steel edge girders and floor beams were hung 64 ft above the existing roadway in the main arch span with new suspenders. MATTHEW SPOTH, WSP
Design began in 2011 and called for the rehabilitation and strengthening of the arch, construction of a new suspended roadway and new approach roadways, and demolition of the original suspended roadway.
Construction began in 2013. Traffic on the bridge was reduced from two lanes in each direction to one lane in each direction, and traffic was moved to one side of the existing roadway, allowing the remaining two lanes to be used as a work zone. The lanes of the existing bridge were 10 ft wide. During construction, the two lanes that remained open were increased to a width of 11 ft and were separated by a painted median of 3 ft. Because of carefully planned staged construction, the bridge remained open to traffic during peak hours, with lane closures limited to off-peak hours, weekends, and overnight. The navigational channel remained open throughout construction.
New single-column piers and pier caps for the higher approach structures extended up through the existing closed roadway lanes. Half the new roadway superstructure, composed of hollow concrete box girders, was erected from these single piers using an erection gantry and balanced cantilever construction. More than 4,000 tons of steel plates were used to strengthen the main arch span to accommodate higher wind loads and allow for future light-rail as well as help support the arch when it would be temporarily carrying two roadways.
As specified by the New York City-based design joint venture (DJV) team of WSP USA and HDR, chosen by the Port Authority, new steel edge girders and floor beams were hung 64 ft above the existing roadway in the main arch span with new suspenders in the following sequence:
- Transfer girders were used to support one existing floor beam at a time at the edges.
- The force was transferred from the existing suspenders to the transfer girders, thereby enabling the contractor to remove the existing suspenders.
- The new floor beam and edge girders for one panel were erected above the existing floor beam and were connected to the lower arch chord with new suspenders.
- Temporary suspenders were then connected from the new floor beam to the existing floor beam below.
- The load in the transfer girders was shifted back to the temporary and new suspenders. The transfer girders were then advanced to the next existing floor beam in stepwise fashion to complete the support framing for the new roadway.
- As each new panel of floor beams was erected, the lateral bracing and stringers for that panel were erected as well.
- After the steelwork for the new floor system was erected, half the new deck slab was constructed using lightweight concrete.
Meanwhile, taller columns were added to the steel arch at the end bays, new roadway portals in the arch were opened and framed with new steel to support the higher roadway, and additional plating was installed to strengthen the arch span. At this point in the project the steel arch was temporarily pulling double duty: instead of supporting one roadway, the arch was supporting the weight of two roadways along with heavy construction equipment, with the new lightweight concrete roadway deck reinforced with stainless steel rebar and the steel arch truss permanently strengthened for the construction load case.
The new deck of the Bayonne Bridge is composed of hollow concrete box girders that were erected from single piers using an erection gantry and balanced cantilever construction. COURTESY OF HDR
Finger joints and expansion bearings were used at the intersection of the new roadway with the lower chord of the arch truss to accommodate the expansion and contraction of the span because of temperature changes. Wider and taller arch abutment towers, which accommodate the transition from the segmental concrete approaches to the steel arch structure, were also built around the existing abutment towers at the ends of the arch span.
For the approaches, stainless-steel rebar was used in the roadway deck of the superstructure's precast box girder segments to maintain a 100-year design life. For the arch, slow deterioration of the deck would most likely lead to corrosion damage to the supporting structural steel; therefore, steel repair would most likely have been required at the time of deck replacement. The use of stainless rebar on the arch span roadway was consistent with the mandate to ensure 100 years of serviceability with limited need for extensive repair.
The pedestrian/bicycle path, with a utility gallery underneath, was installed on the east side of the bridge. This gallery is used for electrical and electronics conduit runs as well as water for the fire-suppression standpipe system. However, some of the conduits and pipes could not fit within the confines of the east utility gallery on the main span, so space had to be made for utility service on the west side. The west side access catwalk is an extension of the top deck slab and is supported on the fascia edge girder. A portion of its 5 ft 5 in. width now supports utilities while maintaining its functionality as an access catwalk.
The number of conduits and pipes resulted in a significant design load on the bridge. Therefore, all conduits and services supported by the east and west utility galleries converge at electrical rooms just under the roadway at the arch abutment towers. From there they are directed inside the concrete box approach girders from which they continue to the approach abutments.
FIGURE COURTESY OF HDR
The surface of the shared-use path is a concrete-filled grid deck supported on transverse steel beams, which are attached to the new floor beams on one side and to a propped strut from the base of the floor beam on the other side. On the approach structures, the shared-use path is accommodated by a widening of the top slab of the northbound box girder. For the arch structure, it is cantilevered off the new floor beams.
An earlier design envisioned installing the foundations for both pier columns at each pier location early in the project and constructing the lower portion of the piers for both northbound and southbound construction up to the intermediate horizontal strut using cast-in-place construction and precast segmental pier construction beyond that. However, during the early stages of construction, the Port Authority, the DJV, and the construction joint venture (CJV) of Skanska Koch and Kiewit, headquartered in Queens, New York, decided to construct separate footings and piers for the northbound and southbound approach roadways using all-segmental construction. The proposal anticipated a higher efficiency due to using one method of construction, precast throughout.
In addition to redesigning the pier columns, the design team added a temporary vertical pipe support to stabilize the temporary construction phase when half of each two-column pier was completed. This bracing system eliminated the need to construct half the southbound roadway substructure, which would otherwise have been used to brace the northbound roadway substructure. This ultimately took the installation of the second set of foundations off the critical path for achieving the new, higher navigational clearance and opened the northbound roadway to vehicular traffic with one lane in each direction (the project's first milestone). Eliminating the southbound approach roadway foundations from that milestone reduced the construction risks associated with geotechnical uncertainties for achieving the new, higher navigational clearance as soon as possible.
Arch Elevation. FIGURE COURTESY OF HDR
To further expedite the schedule, the design team developed a precast-concrete-clad, horizontal, midheight strut for the tall piers that replaced the function of a cast-in-place strut, which would have required extensive falsework to support the weight of the wet concrete. A steel truss was designed to support the concrete cladding. The completed two-column approach piers were designed to complement the curved arches of the original piers, and the transverse arched bracing struts in the taller pier columns recall the elevation profile of the original approach roadways.
Project design and construction were carried out to minimize environmental impact to the waterway. This allowed for an expedited environmental review of the project. One improvement with the new bridge is that all roadway surface water is collected; solids are allowed to settle before being introduced into New York stormwater collection systems, or they are detained before being permitted to flow into the Kill Van Kull outfall on the New Jersey side.
Avoiding right-of-way issues at the approaches of the bridge was critical in keeping construction on schedule. By keeping the proposed construction within the existing right-of-way, no property takings were required. Property takings would have triggered an environmental impact statement and added at least four years to the project's duration, which would have been incompatible with the stated goal of being ready as soon as possible for the next generation of container vessels.
By avoiding this setback, the Port Authority was able to prepare an environmental assessment to obtain the bridge permit for construction. The environmental assessment was produced in nine months and confirmed that the project's design would not create any permanent impact to the adjacent neighborhoods.
The new two-lane roadway, which will eventually be the northbound span, was completed in February 2017. Construction has begun on the southbound span. FIGURE COURTESY OF HDR
Once the two-lane roadway was completed in February 2017, traffic was routed to it. Attention then shifted to the demolition of the lower suspended roadway over the navigation channel, which would finally allow post-Panamax ships to pass through the Kill Van Kull. By June 2017, demolition of the old roadway was done.
Once the navigational clearance channel was completed and the old roadway demolished, the next step was to demolish the old approach structures. The second set of pier columns was erected for the second concrete box girder roadway. All Bayonne Bridge traffic currently uses the roadway that will eventually become the northbound span (still one lane in each direction), while construction continues on the second roadway that will accommodate southbound traffic.
On September 7, 2017, for the first time, a post-Panamax container ship, T. Roosevelt, loaded with 14,400 TEUs, entered the Kill Van Kull at slack high tide and passed under the Bayonne Bridge with approximately 30 ft of spare headroom, making its way to the Port Newark- Elizabeth Marine Terminal. It was an amazing moment not only because of the impressive size of the ship but also because this improvement to the bridge will have a profound impact on the region's economy. The bridge is also the Port Authority's fi rst open-road, electronic-only toll facility, using a toll gantry on the Staten Island side of the bridge.
Current work on the bridge approaches includes construction of new posttensioned precast concrete piers and parallel segmental approach box girder spans adjacent to the inservice traffic lanes. Completion of the Bayonne Bridge Navigational Clearance Project is targeted for mid-2019.
While the design scope was clearly delineated among the DJV fi rms and 18 subconsultants, they all worked on various aspects of the steel arch truss span and the segmental concrete approaches. WSP performed the majority of the design for the foundations and substructure piers as well as much of the civil work. HDR was mainly responsible for the design of the approach superstructure and staging. Electri-cal and electronic work were performed by both firms and their subconsultants.
With a clearance of 215 ft, post-Panamax ships can now pass under the Bayonne Bridge. FROM WSP USA BY REHEMA TRIMIEW
ProjectWise, project collaboration software by Exton, Pennsylvania-based Bentley Systems, was used as the platform for sharing design documents and files. Submittals during the construction phase were made using Trimble's e-Builder (based in Sunnyvale, California) construction program management software that was tailored to the project. Technical production for the DJV was directed by HDR through the engineers of record, Joseph LoBuono, P.E., lead designer for the DJV, and Paul Nietzschmann, P.E., formerly of WSP.
The need for immense coordination between the DJV and the CJV on such a large project could have proved insurmountable without careful planning and continuous communication. Key parties in the two joint ventures implemented partnering sessions to ensure everyone was attuned to one another's needs and to keep construction on schedule.
The project received the American Council of Engineering Companies' 2018 Grand Conceptor Award in April. The project was selected by a panel of nearly 30 judges (from a group of 160 finalists) as 2017's most outstanding engineering accomplishment. The complexity, scale, and economic importance of this project—and the ability to save a landmark structure and outfit it for a renewed purpose- have been lauded by industry peers.
The economic benefit to the region, and the entire East Coast, of raising the roadway cannot be overstated. It ensures that these ports will continue to thrive as larger ships become the standard mode of shipping.
Joseph LoBuono, P.E., is vice president and HDR's national technical director for major bridges. He was the lead designer for the design joint venture (DJV). Roger Haight, P.E., ENV SP, M.ASCE, is vice president and long-span bridge group leader for WSP USA in New York City. He served as the construction project manager for the project. Chester Werts, P.E., S.E., P.Eng., is a professional associate and senior bridge engineer for HDR. He served as the superstructure design lead for the project. Beth DeAngelo, P.E., is vice president and New York deputy area manager for WSP. She served as WSP's project director for the DJV. Christopher LaTuso, P.E., is vice president and New York/New Jersey transportation program manager for HDR. He served as HDR's project principal for the DJV.
Owner Port Authority of New York and New Jersey, New York City
Designer HDR/WSP USA, a joint venture, New York City
Engineers of record Joseph LoBuono, P.E., Newark, New Jersey, and Paul Nietzschmann, P.E., New York City
Construction joint venture (general contractor) Skanska Koch and Kiewit, Queens, New York
Precast concrete Bayshore Concrete Products, Cape Charles, Virginia
Steel fabricator Cimolai, Porcia, Italy
Posttensioning supplier Schwager Davis, San Jose, California
Electrical consultant Arora Engineers, Philadelphia
Mechanical/plumbing consultant HDR and WSP, New York City
© ASCE, Civil Engineering, November, 2018