In mid-February, a rockfall event occurred along a section of Interstate 70 near Glenwood Springs, Colorado. A large boulder fell onto the westbound lane, destroying the guardrail, before landing on the eastbound lane below. Subsequent rockslides left large boulders almost entirely blocking the interstate highway and endangering motorists, some coming to rest on a semi-trailer.
GeoStabilization was contracted to help the Colorado Department of Transportation (CDOT) to stabilize the hillside above. CDOT’s Geohazard Program managers determined that the mass above the roadway was still active and endangering the Interstate below with the threat of additional rock slides.“It’s very active,” said Spike Priestly, GeoStabilization International® Superintendent, told reporters at the Denver Post. “We had stuff coming down on its own last night. Everything is unstable.”
A joint team of Geostabilization and CDOT personnel sprang into action, created a stabilization plan, and mobilized GeoStabilization’s skilled Rockfall Remediation Technicians (RRTs). The RRTs, inserted above the interstate by helicopter, worked quickly to remove much of the unstable rock. This allowed the reconstruction and repairs to begin on the damaged highway structure while additional measures continued to stabilize the slope above. IDS deployed a radar monitoring system that allowed CDOT to be alerted to any destabilization of rocks, both during the stabilization operations and shortly thereafter.
With the Interstate closed, the estimated 300 travelers per hour were detoured nearly 150 miles around the canyon. Once the slope was initially scaled to remove any remaining unstable boulders, CDOT was able to progressively reopen the lanes of traffic to the traveling public. Despite snowy conditions, limited road access was restored in less than a week with lanes in both direction opening days after.
“This is one of the most extreme rockfall events, regarding structural damage, that I have seen,” Cameron Lobato, GeoStabilization’s Western Director, said. “This was truly an emergency job, and our significant presence in Western Colorado allowed us to mobilize very quickly.”
He added that the section of the interstate was one that GeoStabilization’s founders, Bob Barrett and Al Ruckman, helped to construct years ago while they were employees of CDOT. “We’re immensely proud,” noted Lobato, “that this generation of GeoStabilization employees was able to safeguard and repair a section of interstate constructed, in part, by our Founders.”
To learn more about the rockslide along Interstate 70, please see the links below.
A variation of karst sinkhole grouting is the grouting of mined coal seams and workings located below existing infrastructure that exhibit the potential to propagate to the surface and cause sinkholes and/or subsidence.