Modern Mining September 2019

using Geobrugg’s mesh. Mesh panels can be connected with a T3 connection clip that Geobrugg supplies. The T3 clip has a wire diameter of 4 mm and a tensile strength of 1 770 N/m 2 , equiva- lent to the mesh itself. The coating on the mesh makes use of Geobrugg’s Ultracoating® or Supercoating® cor- rosion protection formulation. This coating is a 95 % Zn and 5 % Al compound.

Above: QUAROX ® rolled cable net drape at an open-pit operation.

Left: Round spikeplate grabs the mesh in six positions ensuring optimal load transfer.

The mesh is very light relative to its strength due to the high-tensile wire, making mechanical installation easy and safe. The mesh is characterised by high mechanical resistance, high energy absorption capability and long life. Geobrugg systems The company’s systems are specifically developed to resist dynamic loading and to allow for larger deformations. Geobrugg’s support system can absorb higher energies as all the company’s prod- ucts are made of high-tensile steel. As such, the resulting material strength of the Geobrugg mesh is around three times stronger than the mild steel vari- ety. Other qualities of the high-tensile steel product include the fact that the mesh is lighter than other mild steel products. The MINAX® 80/3 mesh weighs in the order of 1,45 kg/m 2 .

Geobrugg’s high-tensile steel mesh and systems go through a rigorous testing and certification pro- cess. Geobrugg’s mesh, in conjunction with leading yielding rock bolts, is a ground support system of choice in conditions where rock bursts are likely to occur. The company’s MINAX mesh can be used as an alternative to time-consuming mesh and lacing practice. Using the 4 mm mesh, the need for shot- creting can be eliminated. Geobrugg mesh also has a higher resistance to corrosion than mild steel products. Full-scale dynamic tests Rockburst damage is a risk in underground excava- tions due to seismicity and the blasting processes.

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September 2019  MODERN MINING  43