Pittsburgh Landslide Leads to Months-Long Construction Fix
A contractor will be selected this week
About 13 days after a landslide collapsed a large roadway near Pittsburgh, Pennsylvania Dept. of Transportation officials selected Golden Triangle Construction to speed repairs on a 500-ft-long plus section along State Route 30.
On April 20, the Imperial Pa.-based contractor beat out eight other contractors for the reported $6.54 million project, according to media reports. Work is expected to be completed in June.
Contractors removed debris from the site and performed drilling tests starting on April 7, when a landslide caused the roadway to collapse. The roadway’s permanent fix includes replacing a collapsed retaining wall.
The Pennsylvania Dept. of Transportation spokesman Steve Cowan says the permanent fix will involve buttressing the base of the hill with a new retaining wall, backfilling material behind the wall and rebuilding the roadway. “The landslide remediation project itself is not unfamiliar work for engineers and contractors in this area,” Cowan says, “but the sheer size of the landslide and high-profile nature of the area make this unique.”
Harrisburg-based Gannet Fleming designed the new retaining wall for the site. The 20-ft tall by 400-ft long wall is about the same height as the old wall, but more than twice the length, PennDOT District 11 district executive Cheryl Moon-Sirianni said during an April 17 news conference.
The new roadway will be anchored in bedrock to prevent future slides, Moon-Sirianni said.
Geotechnical drilling showed that in the section of the road that collapsed, bedrock was up to 60-ft below the surface of the roadway.
Allison Park Contracting, based in Gibsonia, Pa., established benching and is pushed debris down the slope. The contractor has hauled 102 loads of debris from the site. Murrysville, Pa.-based Armstrong Drilling was also on site on April 17 to drill test holes.
PennDOT officials first noticed issues with the road before it collapsed, but they thought it was a drainage problem. On April 7, a large concrete retaining wall built downhill from the roadway began to fail. The wall, which was supporting the affected stretch of the road, collapsed on the morning of April 7, causing the landslide.
“The protection of the remaining properties adjacent to the landslide is ongoing,” Cowan says.
The landslide displaced 31 residents. About 30,000 motorists travel this stretch of PA State Route 30 daily, according to PennDOT. Located in the East Pittsburgh/North Braddock areas—municipalities close to, but not a part of, the city of Pittsburgh—the road connects Pittsburgh to many of its East suburbs and to Greensburg and points east.
No injuries or car vehicle accidents were caused by the collapsed roadway, and no one fell in the collapsed area or wrecked because of it. Many local residents were displaced by the incident. Two apartment buildings in an apartment complex, and one residential house were demolished as part of the start of the fix of the road. The structures were about 150 ft. from the road and had to be removed for safety reasons and to repair the road.
This story was updated with new information on April 30.