Most highway projects don’t require workers to rappel down a rock face.
But the MD 135 slope stabilization work project isn’t ordinary. Since April, special teams hired by the Maryland Department of Transportation State Highway Administration (MDOT SHA) have been working to shore up the steep face of Dan’s Mountain along the two-lane highway to prevent rockslides.
MD 135 spans parts of Garrett and Allegany counties. During the project, which is expected to be completed ahead of its scheduled date of June 2022, the westbound lane is closed, and traffic is alternating on the eastbound lane.
“While we never want to disrupt the travel lanes, the greatest concern is safety,” said MDOT SHA District Engineer Anthony Crawford.
Besides the inherent danger, rockslides can result in road closures that impact communities, commuters and commercial truckers.
For example, I-70 in Glenwood Canyon, Colorado, was recently closed for a mudslide that trapped over 100 people in their cars. As a heavily traveled roadway vital to the nation’s supply chain, it added time to truck drivers’ routes, resulting in delivery delays and increased shipping costs.
This summer, a section of US 40 was closed because of a rockslide near Youghiogheny Lake. An entire hillside collapsed, bringing down trees, debris and rocks the size of cars. To ensure motorists’ safety, the Pennsylvania Department of Transportation closed a nearly ¾-mile section of the road for more than seven weeks while debris was removed, the slope stabilized, and the highway repaired. There was more than 7,000 cubic yards of debris in just one part of the roadway alone.
The MD 135 project is designed to prevent these kinds of incidents.
The work includes installing proactive slope stabilization devices, such as steel wire mesh, shotcrete, rock dowels, grading, drainage and soil nails at six separate locations along the highway.
Reaching the steep rock face was challenging because there is no access from above.
Access Limited, which works in the U.S. and other countries on custom drill rigs for steep vertical terrain, is using highly trained rope crews to install the slope stabilization devices and remove loose rocks. A trackhoe is also clearing debris and digging trenches.
“I use common sense when deciding whether I can get to a specific place or not,” said veteran trackhoe operator Dean Dayton.
Crews, supervised by MDOT SHA Project Engineer Craig Diehl, are currently finishing up work on two of the six sites.