Geotechnical monitoring instruments, such as extensometers, are frequently used in underground mines as a way to perform ongoing convergence monitoring.
But what about areas where it is not feasible to install these devices, or where convergence monitoring needs to be done prior to the installation of instruments, e.g. during the development of a new mine or the expansion of an existing underground mine?
There are also cases in which an extra layer of monitoring is called for to supplement the data derived from installed instruments, e.g. high-risk or high-traffic areas.
In both of these cases, 3D laser scanners provide a useful solution. The 3D point cloud data they produce can be used to rapidly and accurately determine if convergence is occurring. By performing two scans of the same area and then comparing the results, risky situations can be quickly spotted and appropriate action taken.
It must be noted that a big part of the success and usefulness of this practice lies in the speed with which scanning can be performed and how soon after, and how often, subsequent scans can be performed.
In some cases, static scanners have been used for convergence monitoring, but they are limited by the time it takes to set up a scan, then disassemble, move and re-assemble scanning rigs (often these include a tripod and related hardware).
Fortunately, a better option is available: mobile convergence monitoring. This is achieved by using a mobile 3D laser scanner, e.g. the uGPS Rapid Mapper™.
This rugged, simple-to-use, low-maintenance 3D mine scanner is purpose-built for underground mining and can rapidly generate accurate 3D point cloud data for mobile convergence monitoring purposes.
This scanner can simply be attached to an existing vehicle and driven through the mine, creating and gathering data as it goes, making frequent scans possible and lowering overall scanning time.