Seen here is the I-79 Bridge pier footer concrete placement.
The Pennsylvania Turnpike Commission is currently heading up an interchange project in Allegheny and Washington counties.
PA Turnpike 576, Section 55C2-1 is a project that extends from approximately 1 mi. west of I-79 in Allegheny County through an interchange connecting PA Turnpike 576 with I-79 and ends at Morganza Road just north of Cecil-Henderson Road in Washington County.
The construction of the interchange includes the partial reconstruction of I-79 from the Southpointe Road Interchange to Alpine Road. The project also includes 2 mi. of PA Turnpike 576 mainline construction, 3 mi. of I-79 reconstruction, seven interchange ramps, four bridges, two bridge widenings and two new intersections with PA Turnpike 576 ramps and Morganza Road.
When complete, there will be three southbound I-79 lanes from Alpine Road to the Southpointe Interchange and there will be a free-flow interchange between I-79 and PA Turnpike 576. (which is the I-79/Toll576 interchange).
The contract was awarded in February 2019, with notice to proceed given on Feb. 4, 2019. The completion date is set for June 24, 2022. Northbound to westbound and eastbound to southbound movements of traffic will be in place in the fall of 2021.
The prime contractor is Walsh Construction, with Chuck Zugell serving as project manager. Steve Hrvoich is the PA Turnpike construction engineer manager overseeing the entire project.
The full dollar amount of the project is $174.3 million.
Work includes the following:
- approximately 1.5 mi. of new mainline toll road 576,
- approximately 6 mi. of new interchange ramps,
- the widening of approximately 3 mi. of I-79,
- a full interchange between the new 576 and I-79,
- four new bridges and two bridge widenings,
- nearly 7 million cu. yds. of earthwork,
- 10 traffic control phases on I-79, and
- the excavation of new 576 under existing I-79.
"There are various challenges associated with a project of this scale," said Renee Vid Colborn, public information manager/west of the PA Turnpike Commission. "One of the primary ones is performing complex and large-scale construction with a four-lane interstate highway running through the middle of the job site. The interstate separates the project into three primary work areas, west of 79, east of 79 and 79 itself. We have roughly three million cubic yards of earth that need to go from the east side to the west side while keeping traffic flowing. That is part of the reason that 576 will go under I-79, so that Cat 777 haul trucks can go under the highway hauling 100 tons of dirt and rock per load from one side of the job to the other."
Another challenge noted by Colburn is the proximity to the National Cemetery of the Alleghenies.
"This is an important landmark in this area and it is treated with the utmost respect as they bury up to 10 soldiers here daily," she said. "Making sure that they have continuous access and that information is provided to them on a regular basis is critical for family members coming to visit loved ones' memorials as well as funeral processionals to be able to navigate the area as smoothly as possible."
Necessary earthwork presents another challenge.
"To excavate to the depths that we are involves extensive removal of bedrock and that requires blasting" Colburn said. "Blasting is something that is fairly routine in this area, but it does require close coordination with neighbors as well as existing roadways and emergency services. There will be up to 60 blasts that will require temporary traffic slowdowns on I-79 to perform the blast and verify the road is clear prior to allowing traffic back through the work zone. This has already been done about 20 times to date without any complications."
Colburn noted that this project is the final section out of six major contracts that make up a 13-mi. stretch of brand new Turnpike roadway. It is also the section with the most complex interchange, so about 11 mi. of brand new road will be complete and waiting for this section to be completed in order to open to traffic.
"It requires coordination with PennDOT Districts 11 and 12 because the county line runs right through the middle of the project," Colburn said. "It involves widening of the existing interstate while constructing the new roadway and digging under the existing active interstate by shifting traffic and building new bridges."
Colburn reported that there are more than 70 subcontractors, fabricators and suppliers for the project, but Walsh is self-performing the vast majority of the major work. Wampum is performing blasting, Alvarez will be doing bridge girder erection, North Suburban is doing all erosion and sediment control work, Power Contracting is doing ITS work and Stone and Co. is supplying all concrete including an onsite batch plant.
Major equipment includes:
- eight Cat 777 trucks,
- 20 Cat 745 articulated trucks,
- a Cat 6015 excavator,
- Cat 374, 349 and 335 excavators,
- Cat D6, 8 and 9 dozers,
- Grove 300-, 400- and 550-ton cranes,
- a Liebherr 250-ton crane,
- a Link-Belt 218 crane, and
- GOMACO 6300 and 2600 pavers.
Colburn reported that the project involves 7 million cu. yds. of earth, 7 million lbs. of structural steel girders, 3 million lbs. of reinforcing, 1,000 linear ft. of pre-stressed concrete beams, 20,000 cu. yds. structural concrete, 350,000 sq. yds. concrete paving, 9 mi. of drainage pipe and 28 mi. of pavement base drain. CEG