#KDOTTUESDAY: Mine grouting continues on K-7 modernization project

An agitator truck is ready to pump grout through the hoses to the stinger. The grout mix can be pumped directly into the top of the truck at the concrete plant on the project.

The long pipe on the track hoe boom,

called a stinger, pumps grout through

previously drilled holes to fill the 

underground voids and form a 

barrier wall.

Today's #KDOTTUESDAY takes us to southeast Kansas.

Long-abandoned underground mine voids that were part of the Weir-Pittsburg coal bed are being filled as part of the K-7 widening and modernization project in Cherokee County. Crews have been working steadily to pump concrete grout into holes drilled five feet apart along a four-mile section of the project.

 The grouting will create a barrier wall to support the new highway alignment to the west of the centerline.  According to Regional Geologist Denny Martin, the completed barrier wall will convert the mine voids into room-like spaces. These small underground rooms will then be filled with more grouting material.

The entire project includes 11 miles of K-7 from U.S. 160 at Columbus north to U.S. 400 at Cherokee. The roadway is being widened to 44 feet, with 12-foot driving lanes and 10-foot shoulders. The first phases of work started in 2016. 

The mine grouting is part of the final phase of highway reconstruction, from U.S. 160 north to K-102. Koss Construction of Topeka is the primary contractor.