For the first 11 miles of construction of the Southern Beltway, the concept has been pretty much the same: knock down hills, fill in valleys and create a flat surface for the new 13-mile toll road on the Allegheny-Washington County border.
The last section is different. This time, Walsh Construction II simply will knock down a 105-foot-high hill beside Interstate 79, then dig down about 35 feet underneath it to to create a valley for the new highway. New bridges will carry the interstate above it.
But there’s really nothing simple about it.
“It’s got unique challenges,” Josh Farley, assistant manager on this section of the project for Pennsylvania Turnpike consultant CDR Maguire, said after a tour Thursday of the site between the National Cemetery of the Alleghenies and and the County Line Road Bridge.
“It’s not as difficult to go under a highway as you think. We’re going to ram the traffic over here while we build a bridge over there. Then we’re going to ram the traffic over there while we build a bridge over here.
“But it’s still complicated.”
New landscape
Walsh crews just started work on the interchange this spring and already the changes in the area a short distance north of the National Cemetery are obvious:
• Traffic on the northbound side of the interstate has been shifted to the right, using what ordinarily is the berm.
• The median is under construction so it can handle part of the southbound traffic later this year, clearing the way for bridge construction on the southbound lanes.
• Along the southbound side of the interstate, a well-coordinated team of excavators and dump trucks already has taken the first 30 feet off the top of the hill adjacent to County Line Road, dumping most of it a few hundred yards away to fill the center of a looping ramp that will carry traffic from the southbound interstate onto the new highway.
“We’re just scratching the surface,” Mr. Farley said as he watched the excavation work. “All of that has to come down.”
Among the excavators, another truck is drilling holes to place blasting charges in the hillside to break rock formations into smaller pieces. Through Thursday, the contractor had set off charges four times, causing short traffic delays on the interstate.
“It isn’t anything dramatic or real exciting,” Mr. Farley said. “It’s just heaving it a little bit to make the pieces a little smaller.”
The trucks are dumping most of the material from the hill onto the nearby plain about the size of eight football fields side by side.
First section done
Building three bridges, an overpass, an interchange and moving five million cubic yards of earth have been completed in the first of six major road construction contracts. That section, four miles from Route 22 to Quicksilver Road, had its final inspection Friday.
Steve Hrvoich, the turnpike’s construction engineering manager, said Independence Excavating would have some final punch list items to finish after the inspection. The company, which had a $90.85 million contract, likely will be removing equipment from the site through the end of July.
But Mr. Hrvoich stressed that Independence’s exit doesn’t mean any part of the highway will open soon. The project is designed for all of it to open at once in 2021, and there are still major items remaining such as painting lines and installing road signs before the section is complete.
Other sections are coming along as well but there have been some situations and delays to deal with, especially in the 3.2-mile section between the Panhandle Trail and Cecil Reissing Road in Cecil and North Fayette. Work and record rainfall in that area near McDonald caused chronic flooding problems in 2017 and 2018.
Contractor Joseph B. Fay, which had a $90.85 million contract, received an additional $1.33 million last year to deal with more abandoned oil wells discovered on the site and more soil stabilization work. Last month, the turnpike commission approved another $1.48 million to cover additional soil stabilization work attributed to the rainfall last year, boosting the company’s contract to $98.76 million.
The company also is expected to receive a six-month extension to December to finish its work. The project was delayed after crews discovered and had to remove about 135,000 cubic yards of colluvium in an area where crews were supposed to install one of the piers for a bridge across Route 980.
Mr. Hrvoich described colluvium as the soft remnants of a landslide thousands of years ago that is unsuitable for construction. Test borings indicated a small amount but crews found substantially more.
Since the highway isn’t scheduled to open until 2021, any delays in those early sections are of little consequence.
Tight Schedule
That’s not the case for the interchange with I-79, which is on a tight schedule to open the project on time, said Mr. Farley.
After a dry beginning to spring allowed crews to get ahead of schedule, rainy spells in May and June have been troublesome, causing the contractor to do no work for one four-day stretch.
“They’re not as far along as they want, but they’re still on schedule,” Mr. Farley said.
Handling the traffic on the interstate and coordinating the work of Walsh with contractors on adjacent parts of the project, along with communicating with the Pennsylvania Department of Transportation and officials from neighboring communities have been the most daunting aspects of this project, Mr. Farley said. Overall there are 4,000 pages of plans for the interchange.
Right now, the contractor wants to finish the new bridge on the southbound lanes during the current construction season so crews can prepare to move all traffic to that side and repeat the process on the northbound side beginning next spring. But several pieces have to fall into place.
For example, another contractor’s work on relocating Morgan Road, which ordinarily provides primary access to the National Cemetery, has to be completed for work to begin on the northbound side. That’s because work on the northbound side will close County Line Road, which is being used temporarily to get to the cemetery.
During the northbound work, the County Line Road Bridge over the interstate will be permanently removed and the road will end in a cul-de-sac along the southbound lanes.
“There are a lot of players involved here,” Mr. Farley said. “It’s cliche, but coordination and communication are always No. 1.
“It’s all designed to fit together like a jigsaw puzzle, but the pieces have to fall in place in the right order.”
Ed Blazina: eblazina@post-gazette.com, 412-263-1470 or on Twitter @EdBlazina.
First Published: June 30, 2019, 4:53 a.m.
