Annual Report 3 - New Mexico - Energy, Minerals and Natural ...

Installation of a
geosynthetically
confined soil
(GCS®) plug at
the Strieby Shaft
at the Lake Valley
Mine Safeguard
Project Phase IV.
The vertical culvert
provides air flow
for bat habitat in
the mine workings
below.
72
Another technique pioneered in New Mexico is the innovative new toroid tire plug closure technique for shafts,
adits and open stopes. One of the engineering challenges of abandoned mine land (AML) reclamation is the fact
the ground around a mine opening is often unstable and can cause further cave-ins, even after work to reclaim it has
been completed. Permanently sealing these troublesome openings requires a dynamic, expandable, flexible plug that
expands to fill the hole, even if a minor amount of movement continues to occur or material sloughs away from the
opening sides after the plug is in place.
Toroid tire plugs put a waste product (large-diameter spent tires from earthmoving equipment) to beneficial use.
The tires are either stacked or placed vertically adjacent to each other to plug horizontal, vertical or declined mine
openings. Although this technique was developed in British Columbia, Canada, the Lake Valley Project in New
Mexico was the first use of tire plugs in the United States. MMD has gone on to successfully use toroid tire plugs in
numerous abandoned mine openings across the state.
Photo by: James R. Smith
MMD is always looking for the next new technique to
improve reclamation, such as the recently developed
Geosynthetically Confined Soil (GCS®) concept. The GCS®
plug consists of geotextile panels placed between eight-inch
lifts of compacted granular material that are placed above a
polyurethane foam plug to provide the additional structural
strength necessary to support the fill above the shaft. This
method is currently being used at another abandoned mine
in New Mexico, the Strieby Shaft at the Lake Valley Mine
Safeguard Project.
Although New Mexico has received numerous awards for
reclamation work performed, the most important aspect is
receiving confirmation from leaders in the industry that the
reclamation work being completed in New Mexico is of the highest quality.
PUBLIC OUTREACH: The reclamation of mined lands, whether a historic abandoned mine or under
a current permitting action, often goes unnoticed in the general press and can be easily misunderstood due to the
complex nature of the work to be performed or merely by the sheer size of some of the larger projects. Many times,
concerned citizens or even mine operators are not sure what may be required of a mining operation or even what
operations are active near them. In recognition of this, MMD has expanded its outreach to the public and mine
operators.
Beginning in 2004, MMD redesigned its webpage to provide more information on abandonded mine safeguarding
projects and on current and proposed mining operations, as well as publishing an electronic newsletter, “MMD
Notes,” to inform the public and industry about events involving MMD and mining activities in the state. The
ENERGY, MINERALS AND NATURAL RESOURCES DEPARTMENT