1909 Table 7 - How the solutions map to risks Geotechnical risk Key solutions Roof / wall falls Mesh + bolts + shotcrete (optional) Rockburst Dynamic support (high-tensile resistance mesh and bolts) and seismic monitoring Progressive failure Conservative design and monitoring Post-blast instability Rapid support Uncontrolled exposure Mechanisation & remote operation To effectively manage the risk associated with geotechnics (Table 7), you need to take systems approach and not rely on a single means of control. Long-term improvements begin with good upfront design to avoid instability and are then reinforced properly, fit for purpose ground support that is installed using methods to ensure both quality and reliability. These steps diminish the variability of high-risk areas and increase safety for workers. Continuous monitoring of terrain behaviour creates further integrity in this system and can allow early identification of changes, so that action can be taken before rock mass conditions decline. Increasing system reliability is based upon each discipline having specific responsibilities that are established through rules, exclusion zones, competency requirements, and a regular enforcement of those rules and that these rules are not subject to production pressures. When combined these components create a resilient operating system. This resilient operating system assumes failure can occur, limits worker exposure, and proactively manages geotechnical risk rather than waiting to react to an event once it has occurred. 7. INNOVATIVE FLEXIBLE SOLUTION The use of a high-tensile strength steel wire mesh (³ 1770 MPa), bolted to the surface of the ground (roof and walls) and installed in a mechanised mode, is a proven effective solution to guarantee the ground support (in front dynamic and static load combinations). Figure 2 and Table 8 show the properties of this mesh, and later the mechanised installation method to set it in place, is described (Figure 3). Figure 2 – High-tensile strength wire mesh, dimensions diagram (Geobrugg, 2026) Table 8 – Technical info high-tensile strength mesh, static and dynamic loads (Geobrugg, 2026) Property G80/3.0 G80/4.0 G80/4.6 diagonals x . y [mm] 102 . 177 (±3%) 102 . 177 (±3%) 102 . 173 (±5%) circle inside the rhombus [mm] 80 (±3%) 80 (±3%) 80 (±5%) spiral angle [º] 49º 49º 49º mesh height htot [mm] 12.5 (±1.5) 15.0 (±1.5) 17.0 (±1.0) mesh clearance hi [mm] 6.5 (±1.5) 7.0 (±1.5) 8.0 (±1.0) meshes longitudinal nl [pcs/m] 5.6 5.6 5.8 meshes transversal nq [pcs/m] 9.8 9.8 9.8 tensile strength zi [kN/m] 110 190 300 wire diameter d [mm] 3.0 4.0 4.6 wire quality fy [MPa] ³ 1770 ³ 1770 ³ 1770 wire test resistance [kN] 12.5 22.2 29.4 wire coating Zn95Al5 [g/m2] ³ 150 ³ 150 ³ 150
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