PITTSBURGH, PA (October 8, 2020) After a year of complicated work by several agencies and utilities to address a sinkhole and other damages, 10th Street in Downtown Pittsburgh is finally reopening today.
Pittsburgh Public Safety officials responded to the sinkhole on October 28, 2019, which was so large (60 by 35 by 18 feet deep) that it swallowed the rear of a Port Authority bus. The driver of the bus and its riders were safe, but Public Safety’s next concern was the stability and safety of steam lines, water and sewage lines, and communications infrastructure perched below the street’s unsupported, cantilevered slabs of concrete. With the assistance of Allegheny Crane Rental and DiPasquale Engineering, officials ultimately brought a crane to the scene to carefully remove the bus while not further disrupting the infrastructure below.
Plans were to reopen the street within weeks. However utility companies found there was indeed damage to infrastructure beneath 10th Street and they began months of work to fix the damages, work that was further complicated by the COVID-19 pandemic starting in March of this year.
The City’s response was overseen by Chief Operations Officer Kinsey Casey and included work by Public Safety, Public Works, and Mobility and Infrastructure. Responding utilities and companies included Duquesne Light, Peoples Gas, Comcast, Verizon, Port Authority, Pittsburgh-Allegheny County Thermal (PACT), and the Pittsburgh Water and Sewer Authority. Officials from the adjacent Westin Pittsburgh hotel were also helpful throughout the work.
Restoration costs were shared 50/50 between the City and PWSA.
“This has been an incredibly challenging year for our city, nation and planet, and the 10th street sinkhole represented everything 2020 has been about — danger, disruption and frustration, but ultimately solutions, due to a lot of hard work by people working together. I can’t thank our partners, and especially our Downtown residents and businesses, enough for their patience and understanding,” Mayor William Peduto said.
Duquesne Light made improvements to the street grid without any outages to customers, and replaced terra cotta conduit run between 3 manholes with new PVC ducts encased in reinforced concrete.
Peoples Gas conducted a complete safety check and performed corrosion protection work on their existing steel pipeline.
Comcast technicians replaced conduit at the site and protect their fiber, which was secured during street restoration. Verizon secured and repaired their lines as well.
Some of the most complicated work was performed by PACT and PWSA.
PACT pumped and removed water and soil materials from steam tunnels and cleaned and sanitized them; removed stray concrete damage; repaired several piping supports and concrete anchors damaged during the incident; reinsulated sections of the main steam line that sustained water damage or needed to be removed to make concrete and support repairs; and made sure the steam line below to was ready for this fall and winter.
PWSA cleared approximately 2,500 tons of debris from the 48-inch sewer running down 10th street to the Allegheny River outfall point, utilizing a vactor machine sitting on a river barge and a diver to remove debris from the river bed.
A PWSA contractor then took the lead on removing all debris from the sinkhole, giving space for other utilities to repair damaged infrastructure. As part of the rebuilding process, PWSA also installed a new bulkhead to the sewer manhole that was damaged when the street collapsed. After all repairs were complete, they filled the hole with stone, replaced bricks, and poured new concrete to reopen the street to car and pedestrian traffic.
At the end of the project, crews completed the following:
- Added approximately 746 tons of stone backfill to the sinkhole
- Replaced 2,097 square feet of bricks
- Poured approximately 395 tons of concrete
- Logged over 1,100 hours of work to complete the project
