Bayonne Bridge Project Gets a Lift

Bayonne Bridge Project Gets a Lift

Gantry crane footing bear directly on the reinforced soil.
Reinforced Earth Product in Field
Bayonne, NJ
Port Authority
Skanska Koch Inc. Kiewit Infrastructure Co. (JV), DBA Skanska Kiewit JV
Ferreira Construction Co.
Faddis Concrete Products

Reinforced Earth® mechanically stabilized earth (MSE) retaining structures have long been known for their ability to support bridge abutments. Now, working with an innovative design-build contractor, The Reinforced Earth Company (RECo) is designing and supplying Reinforced Earth structures that also support bridge building.

The Bayonne Bridge, a historic 1,671 ft. long span crossing the Kill Van Kull and connecting Bayonne, NJ and Staten Island, NY. It was the world's longest steel arch bridge when completed in 1931, and it remains the 4th longest to this day. The story of the Bayonne Bridge raising is driven by a maritime infrastructure story, because the Kill Van Kull is a primary shipping channel for access to major New York area port facilities. The Panama Canal Expansion project, to be completed in 2016, will allow passage of longer and wider ships carrying more than twice as much cargo, but those stacked containers will not fit beneath the bridge's 151 ft. navigational clearance (originally set to meet the needs of the U.S. Navy). So the Port Authority of New York and New Jersey is raising the bridge's roadway (though not the arch itself) by 64 ft., necessitating a matching raising of the approach roadway on each end of the bridge. The new approaches, partially on retained fill and partially on viaduct, are being constructed of – and the viaducts are literally being launched from – Reinforced Earth walls.

The new approach roadways must climb the extra 64 ft. to reach the raised bridge. Wall heights vary by location, but as much as 30 ft. of that climb is accomplished on permanent Reinforced Earth retained fills. For these walls, the Port Authority selected rectangular (5 ft. x 10 ft.) panels along with a smooth steel form finish (Fig. 1). The project is being constructed in 2 phases to maintain traffic flow: first northbound (NY to NJ) with all traffic using the old roadway, then southbound while all traffic uses the newly-constructed northbound lanes, then opening all lanes, with project completion in mid-2017. Reinforced Earth walls with temporary TerraTrel® (Fig. 2) support the half-wide Phase 1 roadway, with Phase 2 construction later butting up to and burying the temporary wall. Since the temporary facing is wire mesh, it will behave just like the rest of the embankment and not result in a hard spot in the center of the finished roadway.

The biggest design challenge arrived when the contractor, Skanska Koch Inc. Kiewit Infrastructure Co. (JV), DBA Skanska Kiewit JV, wanted to place the foundations for the viaduct erection gantry crane on the reinforced backfill of the permanent and temporary Reinforced Earth walls. RECo's experienced structural engineers and designers applied the Skanska Kiewit JV-supplied loads at the prescribed locations to determine the extra quantities of soil reinforcement (reinforcing strips) needed to safely support the gantry. Both reinforcement pullout and reinforcement tensile load requirements increased dramatically due to the gantry crane; instead of the rule-of-thumb 70%-of-height reinforcing strip length for a "normal" wall of similar size, strip lengths ranged from 120% to almost 150% of height. This reinforcement supports the gantry crane as it cantilevers off the abutment end of the Reinforced Earth wall (Figs. 1 and 2) to erect the precast segmental viaduct. After the first segment is set atop the first pier, additional segments are erected by the balanced cantilever method and post-tensioned in place.

Installation of the Phase 1 walls (both permanent and temporary) began in New Jersey in April, 2014, and in New York in late May, with all Phase 1 walls completed during August. These walls were on the project critical path since their completion was required to mobilize and assemble the gantry crane. The numerous Skanska Kiewit JV-driven design changes, required to accommodate the crane, complicated RECo's design and manufacturing process.  Getting the right materials to the job at the right time is always a RECo priority and was consistently achieved on this project with the cooperation and flexibility of the facing panel precaster, Faddis Concrete Products of Kutztown, PA.

The wall erection subcontractor, Ferreira Construction Co., used No. 57 stone for the Reinforced Earth backfill, which enabled the wall erection crews to work faster, in virtually all weather, and with little risk of either poor compaction or out-of-spec moisture content. This was especially helpful in congested areas such as corners at the abutments (Fig. 3), where the large diameter pipe piles required skewed reinforcing strips and more careful, methodical backfill placement and compaction.

An unexpected utility problem on the New Jersey side threatened to derail the project schedule.  Construction would have to stop to avoid placing the load of 20 ft. of new fill on an old brick sewer, thought to have been abandoned but, in fact, found still to be in use. To prevent stopping this critical path wall, RECo proposed a temporary solution to keep fill off the old sewer until it could be relocated. TerraTrel was used to create a "blockout" in the permanent fill so the remainder of the wall could be built (Fig. 4). The bottom panel of the temporarily-withheld column of panels was used as a spacer to define the positions of adjacent panels and, except for this roughly 10 ft. x 20 ft. column of fill, wall construction continued normally. Once the sewer relocation was complete, panels, reinforcing strips and backfill were easily placed to fill the blockout.

Launching a segmental precast concrete viaduct gantry crane, accommodating significant design changes while being on the critical path, creating special details, and doing it all while maintaining traffic on a major New York area highway is simply business as usual for The Reinforced Earth Company. From concept to design to construction, RECo's professionals and products make life easier for owners, engineers and contractors.