Mine Void Grouting Helps Save District 12 Infrastructure

​The heart of Pennsylvania's coal production, the Pittsburgh coal seam underlies a majority of District 12. Over the years, a significant amount of this coal has been extensively mined, leaving large, open voids in its place. As these voids begin to collapse and the ground above sinks, the infrastructure in District 12 sinks along with it. Old unmarked mines under the roadway can create large voids and cause numerous problems for construction projects. This mining can create many different roadway hazards, including sinkholes and large dips, as well as cracking and degradation of pavement structures.

To combat these collapses, the district practices mine treatments in construction projects as necessary. During planning for new construction projects, when a mine void is encountered, a grouting plan is often set in motion. This method includes drilling holes down into the void and taking video footage to determine its extent. A grout mixture is then placed in the drilled holes to fill the void and prevent any future collapse. These mine void treatment practices are a key component in keeping the district's roadways stable and keeping the drivers of our state safe.