Convergence MonitoringA network of instrumented cable bolts (or standalone instruments) deployed throughout the mine, especially in vulnerable or high-risk areas, is a common strategy for monitoring convergence and overall deformation in underground mines. These instruments provide very accurate, detailed data about the status of rock masses, soil deposits, roofs and walls of tunnels, rooms and stopes, shafts and other geological features and parts of an underground mine, and they are especially useful when integrated as part of an overall network made up of a variety of types of geotechnical monitoring instruments.

The use of mobile mine scanners, like the uGPS Rapid Mapper™ 3D laser scanner, is becoming more and more common in modern mines to perform a variety of scanning tasks, some of which are also focused on monitoring. This potentially begs the question – will mobile 3D laser scanners replace geotechnical instrumentation as a primary source of monitoring data?

We believe not– both methods of monitoring have their place in underground mining and approach the task of convergence monitoring (and other types of monitoring) from different angles.

Instrumented cable bolts, contractometers, extensometers and other types of geotechnical instruments that are mounted directly into walls, roofs, shafts etc. of mines provide in-depth information about movements in the area immediately around them, i.e. the type of monitoring each instrument performs is very localized and concentrated on what happens behind the face and surface.

The data from a multitude of instruments is then pieced together to form an overall picture of the status of the mine. Mobile 3D mine scanners provide more of an overall view of mine tunnels, shafts, rooms, stopes, working faces, etc.  The data they produce is also above the surface (i.e. they don’t penetrate into the surrounding rock mass and soil deposits like installed instruments), and they pick up and provide data on times that instruments would not usually monitor, e.g. floors and the position and status of equipment.

Essentially, 3D mobile mine scanners like the rugged, accurate, easy-to-use uGPS Rapid Mapper™, are capable of gathering valuable convergence monitoring data, which complements the information gathered by geotechnical instruments, making the mine even more safe and productive.