PA Turnpike Mine Grout
Location: Irwin, PA
Owner: Pennsylvania Turnpike Commission
General Contractor: New Enterprise Stone & Lime Company
Value: $1.7 Million
Date Complete: December 2010
This project consisted of drilling over 500 injection holes totaling over 30,000-feet and on-site batching of 16,000-cubic yards of grout to stabilize an abandoned coal mine underneath the Pennsylvania Turnpike I-76 between Irwin and New Staton. The work was accomplished in two mobilizations to coincide with the traffic control plan.
The initial mobilization required set-up of an onsite batch plant that produced two primary mixes.
The first mix was a low slump, sand-cement mix having a 28-day compressive strength of 700-PSI. The second mix was a lower strength, medium visocsity, flyash-cement mixture. While traffic was routed through the inside lanes, the grout was pumped up to 2,500-feet to reach injection areas located on the outside lanes.
The second mobilization occurred after traffic was switched to the outside lanes allowing work to be completed on the inside lanes. A Lightnin® mixer was utilized due to space constraints.