Corrosion considerations in the capacity of welded wire mesh

Ground control in underground mines employs rock reinforcement and surface support to maintain the integrity of excavations for their anticipated working life.The performance of a ground support system,however,is more complex and relies on effective load distribution between reinforcement and surface support elements.Typically,failure of the ground support system is along its weakest link,often the surface support.Consequently,the degradation of any ground support element over time will compromise the structural integrity of the ground support system.Degradation of ground support can be due to multiple factors.This paper focuses on the role of corrosion in the long-term performance of mesh.It presents a comprehensive methodology for quantifying the impact of degradation on bolted welded wire mesh over time.This is an important aspect,as the mesh is often the first element that fails in a ground support system.This paper combines information from extensive field and laboratory studies on mesh corrosion with calibrated numerical models to capture the long-term performance of different bolting patterns under a range of corrosion environments.A series of three-dimensional(3D)distinct element models(DEM)were constructed to quantify the impact of different corrosion rate scenarios on the loading capacity,displacement,and failure mechanisms of bolted welded wire mesh in diamond and square bolting patterns.This work can contribute to the management of long-term hazards associated with corrosion of mesh in corrosive environments under non-seismic mining conditions.