Culvert Repair in Corbin, Kentucky

The Challenge

Route 3606 encountered pavement subsidence above two culverts about 0.25 miles apart.

In Corbin, Kentucky, on 3606 between KY 6 and Radio Tower Rd, District 11 engineers encountered pavement subsidence above two culverts about 0.25 miles apart. These dips and the problems associated with the weak surrounding soils presented both rideability and safety issues for motorists. To preserve commuter traffic flow, engineers needed a solution to salvage their weak subbase soils, so they decided to call Groundworks.

Groundworks arrived on location, and after some research, it was confirmed that settlement was not the result of faults in the culvert pipes but weak fill soils around them. Dynamic Cone Penetrometer (DCP) testing evaluated the depth of treatment. Low blow counts were encountered mostly to -4′ and as deep as -8’ in some locations. Polyurethane injections was proposed for the project as a quick and effective way to stabilize the underlying soils.

Key Facts

The Solution

Polyurethane injections was selected as a quick and effective way to stabilize the underlying soils.

For the Corbin project, polyurethane injections was the perfect solution to repair the culverts and taper out the dips. Groundworks crews performed the process, injecting polyurethane injections in a grid pattern over the dip areas. During repairs, one lane was left open while the procedure was completed in the other. Virtually no damage was done to the pavement by using only ¾” holes to complete the operation.

The Impact

Groundworks stabilized the soils and even out the dips in the culverts.

Groundworks was able to stabilize the soils and even out the dips in the culverts. KYTC District 11 engineers were pleased with the results. Compared to full depth replacement and repeated mill and overlay, repair time was significantly reduced by leaving the subbase soils and the pavement in place. The road remained open during the whole process; work was completed in one lane while traffic flowed in the other. Groundworks was able to eliminate rideability issues without halting traffic flow while providing long-term repairs that ensured the safety of motorists and the crew.