Geobrugg has recently installed nails, mesh and spike plates as part of a slope stabilisation system at Alrosa’s Aykhal diamond operation in Mirninskiy Ulus, Russia.
Aykhal is in the permafrost region of Russia, a fact that comes with hazards – for two to three months of the year, rockfalls can occur as a result of melting permafrost. This makes it difficult and, potentially, dangerous for the trucks and operators that come in and out of the underground mine portal and navigate around the former open-pit mine site.
Some conventional wire mesh was widely used at the operation, until now, to safeguard the portal, according to Geobrugg. “As this mesh did not provide enough safety and has to be changed every two-to-three years, Alrosa decided to test Geobrugg state-of-the-art technology,” the company said.
For the protection solution, Geobrugg’s TITAN 40/16 nails with TECCO® G65/3 mesh and P33/50 spike plates were employed. In total, an area of 1,400 m² of mainly fractured dolomite with an unstable layer from 1.1-1.5 m was stabilised, according to Geobrugg. The installation on a 70-85º slope took one month and a Geobrugg Supercoating® was employed for corrosion protection, the company said.
Geobrugg said: “One of the challenges was the delivery of material and drilling machinery to the site: In winter time, you may use the ice road which runs along the river Lena. In the summer, material has to be delivered by ship, which takes one-and-a-half months from the European part of Russia to this site.”
Installation had to be carried out during the short period when temperatures were above freezing – mid-May to mid-September – Geobrugg said.