MINAX® 80/3 surface support mesh
A high-tensile (≥ 1,770 N/mm²) steel wire mesh as an alternative to welded mesh and chain-link underground: light, with knotted edges and little overlap; laid over the bolt pattern by hand or mechanically with MESHA, using G-PLATE plates and T3 clips.
What it does
In an underground drift, surface support stops the rock between the bolts from breaking off and falling. MINAX 80/3 is a high-tensile steel wire mesh developed as an alternative to the welded mesh and chain-link used for this job: it does the same job with less weight and less overlap, and is laid by hand or by machine. The product is Geobrugg AG's; rock bolting and shotcrete work are done by our own crews.
Data
| Property | MINAX 80/3 (manufacturer's product information) |
|---|---|
| Wire | High-tensile steel, at least 1,770 N/mm²; according to the manufacturer three times the tensile strength of mild steel welded mesh and chain-link wire |
| Structure | Diamond-mesh chain link; easy to carry and stack |
| Edge | Knotted ends; overlap on the rock surface is minimized, no exposed cutting wire |
| Size | Roll size produced to suit the bolt spacing and the advance length |
| Connection | G-PLATE: a plate gripping the mesh at six points for load transfer from bolt to mesh; T3 clip: rolls are joined without tools, with full load transfer |
| Coating | Hot-dip galvanized, ULTRACOATING, SUPERCOATING, stainless steel or PET-coated wire; chosen for the conditions in the mine |
Numerical load capacity and roll sizes are taken from the manufacturer's current product document and written in the quotation; the difference between 80/3 and 80/4 is the wire diameter and the resulting static and dynamic capacity.
Where it is chosen
- In fall-of-ground conditions, when a lighter mesh with less overlap is wanted instead of welded mesh.
- In drifts where weight determines the load per worker in manual installation.
- In mechanical installation: with the MESHA handler from a jumbo or bolting rig, without personnel going under unsupported roof.
- If rockburst or heavy dynamic loading is expected, the manufacturer recommends MINAX 80/4.
Installation and acceptance
The roll is laid over the bolt pattern, tightened to the bolts with G-PLATE, and the neighbouring roll is joined with T3 clips; shotcrete is applied over the mesh if needed. At acceptance, plate tightness, overlap and number of clips, and the seating of the mesh on the surface are checked. For underground work as a whole, the mining and tunnelling page.
Source: Geobrugg AG, "Specific solutions for the mining industry" brochure and MINAX product information.