Work continues in Western Pennsylvania to replace the Beaver River Bridge, a project that first began in early 2023. Pittsburgh-based Fay, S&B USA Construction began work on a modernization of the span, which carries traffic on PA Turnpike/Interstate 76.

The $294 million building contract is the largest single-project cost in the history of the Pennsylvania Turnpike Commission (PTC).

The current steel deck truss bridge is one of the oldest original structures on the PA Turnpike and spans a wide and steep river valley. During the project's planning stages more than a decade ago, the PTC required a solution that would enable traffic to continue flowing with minimal detours throughout construction.

Located in Beaver County, near North Sewickley Township, Fay is replacing the 72-year-old steel deck bridge with two parallel cast-in-place segmental bridges. Each new structure is designed to be 70 ft. wide in each direction and is going up immediately north of the existing, single 60-ft.-wide road bridge.

With cast-in-place segmental construction, the concrete superstructure is built directly on the substructure in short segments using form travelers to mold each segment. Once each segment is completed, the form is disassembled and reattached to the end of the new segment to build the next section, Fay explained on its website's project page.

Segmental bridges also offer a variety of benefits, including a reduction of the footprint required to construct piers, superstructures that can easily travel over natural hazards and landmarks and a flexible bridge radius.

In addition, Fay is widening the adjacent highway to carry motorists and commercial trucks across not only the Beaver River, but CSX and Norfolk Southern railroad lines operating on both riverbanks.

The total project area covers approximately 260 acres, Roads & Bridges reported Oct. 20, where Fay will construct five total bridges, install precast culvert extensions, reconfigure an interchange to a half cloverleaf/half-diamond ramp system and widen 2 mi. of roadway.

Its estimated completion is December 2027, according to Fay.

Upon the project's completion, the existing four-lane bridge will be upgraded to include six 12-ft. travel lanes (three eastbound and three westbound), along with 12-ft. shoulders and 10-ft. medians in each direction.

To accommodate the new six-lane design, four early-action bridges, including two overhead Norfolk Southern railroad bridges, were replaced prior to the mainline Pa. Turnpike reconstruction. To date all early projects have been completed, the PTC noted.

The two new Pa. Turnpike/I-76 bridges will each be five-span structures measuring 1,645 ft. in length and supported by four piers, according to information from the contractor. In addition to the bridges' three 12-ft. travel lanes, and on- and off-ramps with shoulders will be included for emergency pullovers.

Heavyweight Concrete Forms Key to Segmental Bridge Building

The new Beaver River Bridge structures will be 200 ft. above the river — 20 ft. higher than the existing bridge system. Cast-in-place segmental construction was decided upon largely due to their height as well as the terrain and structures underneath each bridge, according to Fay.

Segmental bridges are rarely built in Pennsylvania, but the contractor's parent company, Shikun & Binui Ltd., constructs them in Israel, where the firm is based. Due to its familiarity with the techniques used, Fay requested experienced engineers from Shikun & Binui to aid them during the Pennsylvania project.

The project's bridge abutments were completed simultaneously, while all other work on the structures will start with the westbound structure and end with the eastbound structure.

Last February, work on the bridge reached a significant milestone when the form travelers were installed, marking the official start of the segmental portion of construction.

Fay is building the segmental bridges using a balanced cantilever construction process. Starting on pier tables, the company's crews will use one of its four active form travelers to cast 22 concrete segments (each 15. ft. long) per pier before joining them together in a closure pour. A total of 176 segments will be cast to construct both bridges.

After they are assembled on the ground, each of the company's quartet of form travelers weigh approximately 300,000 lbs. and are then lifted into place by heavy-duty industrial cranes.

"It takes about two weeks to cast one segment," Jason Komar, a project engineer with Fay, told Roads & Bridges. "We're working on four segments at any given time."

Once a segment has been poured, the form traveler is launched using mechanical rollers and hydraulic jacks.

Now that Fay has finished the first two cantilevers, the form travelers will be transferred to two other piers on the westbound bridge.

While most segments will have the same width and length, the height of each varies, which can be adjusted by raising the bottom platform up using high-stress post-tension rods.

Engineers Use TBM to Dig New Stream Culvert

Other highlights of the construction work at the Beaver River Bridge site include:

• A new single-span, 150-ft.-long bridge over nearby Pa. Highway 18, and an 80-ft.-long precast culvert extension.

• A reconfiguration of the I-76/Pa. 18 interchange to a half-cloverleaf/half-diamond ramp system, with traffic lights added at the ramps on Pa. 18.

• A total of 1.8 million cu. yds. of Class 1 excavation was done to prepare the entire site.

• Approximately 9 million lbs. of reinforcing steel will be used on the project.

• The use of about 1.66 million linear ft. of steel strand (roughly the driving distance from Pittsburgh to Philadelphia via the PA Turnpike).

• Approximately 47,000 cu. yds. of concrete.

In addition, Fay built a culvert for a new stream under the PA Turnpike. Along with a subcontractor, the company used a tunnel boring machine (TBM) to excavate a 250 ft.-long tunnel for the waterway's drainage. The tunnel was built 40 ft. under the interstate's live westbound traffic.

The TBM drilled through solid rock ahead of a railed conveyor system that followed it to collect and remove debris. The operation ran continuously day and night, Faye noted, which allowed the installation of 72-in. reinforced concrete pipe (RCP) to form the culvert.

When it is completed, the new westbound Beaver River Bridge will open to traffic first while the old bridge will continue to serve motorists heading east. Later, after both new mainline bridges have been completed, the project will conclude with final roadway activities and the demolition of all the old bridges, according to Fay.