Now the emphasis has shifted to rebuilding Route 30 in East Pittsburgh.
Golden Triangle Construction of Imperial received an immediate notice Friday to proceed with the project after the Pennsylvania Department of Transportation awarded the firm a $6.54 million emergency contract. The goal is to install a 400-foot-long, 20-foot-tall retaining wall and rebuild more than 500 feet of the highway by the end of June.
Crews have been working since April 7 to stabilize the hillside between Route 30 above and Electric Avenue below. That’s when three lanes of the highway fell about 30 feet down the hillside, provoking a landslide that damaged a house and two of the five buildings of the Electric Avenue Apartments so severely that they had to be razed.
Earlier this week, PennDOT District 11 Executive Cheryl Moon-Sirianni said consultant Gannett Fleming Inc. went out of its way to design the project with the easiest, most efficient construction methods to complete the project safely. That included checking with suppliers to make sure they could provide precast concrete panels and fabricated steel rods for the wall to meet the accelerated schedule.
“We know how important this highway is,” she said then.
The highway, which carries 25,000 to 30,000 vehicles daily, is a major artery to the Parkway East from North Versailles, East McKeesport and North Huntingdon. It is closed between the outbound East Pittsburgh exit and the Westinghouse Bridge.
PennDOT officials said they expected the contractor to begin work as early as Friday night. Golden Triangle, which submitted the lowest responsible bid out of nine contractors that wanted the work, declined to comment.
Preliminary work is expected to begin immediately but construction of the wall likely won't start for several weeks while the contractor obtains precast concrete panels and fabricated steel rods.
The project will replace a previous retaining wall that gave way during the landslide. Jason Zang, PennDOT’s acting assistant director for construction, said the collapse occurred in a 200-foot area where the bedrock is about 50 feet lower than it is under neighboring parts of the highway.
In addition, lower-quality fill used when the highway was built in the 1930s didn’t provide proper drainage, he said. Record amounts of rainfall that began in February caused the landslide, officials believe.
With the new design, crews will drill holes 4 feet in diameter and fill them with concrete to create pylons to support the wall. In addition, steel rods will be pounded horizontally into bedrock to anchor it.
When the wall is finished, crews will put in about 40,000 cubic yards of fill — 10,000 cubic yards of granular material and 30,000 cubic yards of durable rock — to allow better drainage.
The last step will be rebuilding the highway, which should take about two weeks. The contractor will lay a new subsurface and rebuild the collapsed area as well as 100 feet or more on each end of the collapse to restore the surface.
The winning bid for the project was within PennDOT’s $5 million to $7 million projection. The state will ask the Federal Transportation Administration for emergency funding to pay for that work as well as several million dollars more that it has spent on emergency housing for 31 displaced residents, hill stabilization and designing the wall and road repairs.
Ten residents will need new permanent housing but 21 should be able to return to their apartments when the wall is finished in mid-June. A house about a third of the way up the hillside on Beech Street Extension and owned by Chris Morgan was demolished Friday because slide damage made it uninhabitable.
The displaced residents have been staying with relatives or in hotels at state expense since the slide.
PennDOT and a consultant had been monitoring the section of Route 30 that eventually collapsed for several weeks because it was buckling and lanes of traffic had been reduced. It was closed completely the day before the collapse and residents were evacuated the next morning with no injuries.
Ed Blazina: eblazina@post-gazette.com, 412-263-1470 or on Twitter @EdBlazina.
First Published: April 20, 2018, 7:30 p.m.
Updated: April 20, 2018, 7:30 p.m.
