Maintaining the structural integrity and “health” of all the tunnels in your underground mine is essential if you want to protect the lives and safety of your mine workers and keep your mine operating at full capacity.
By their very nature, the majority of mine tunnels are constructed from solid, inelastic materials, and they are surrounded by rock masses and soil deposits that generally also behave in an inelastic manner. However, introduce the right factors, e.g. water build-up, rock masses that start to shift or slide, or seismic activity (natural or induced by human activity like blasting), and the geological features surrounding tunnels can suddenly start to behave in an elastic manner – with often unpredictable movement and flexing resulting. The stresses caused by this behavior can lead to tunnel damage, including full or partial collapse. This, of course, endangers the lives and safety of miners working underground, and even if nobody is hurt, production will be interrupted while the mess is cleared up, and tunnels repaired or rebuilt, etc.
Prevention is better than cure– the best way to reduce the risk of tunnel damage in your mine is regular and ongoing monitoring, and specifically convergence monitoring because this is one of the key indicators that all is not well behind the tunnel walls. Geotechnical monitoring instruments placed in the tunnel walls and roof are one of the key monitoring strategies employed in many mines, and they do indeed yield valuable data, but it also makes sense to adopt a multi-technique approach – gathering data from more than one source to confirm and add to the information available.
To this end, the uGPS Rapid Mapper™ is a very powerful tool in any underground mine, as it can quickly and efficiently create dense, accurate 3D point cloud data while on the move attached to a mine vehicle that is already moving around the tunnels.
This form of integrated convergence monitoring makes it easy to corroborate the information coming from instruments or gather initial data where no instrumentation is present, giving engineers the tools and data they need to spot excessive convergence in time and take appropriate action.