Sun, Z, Wu, KT, Kruger, SE, Levesque, D, Gagnon, D, Quenneville, Y, Lacroix, R & Royer, R 2019, 'A new paradigm in ground support monitoring through ultrasonic monitoring of clusters of rockbolts', in J Hadjigeorgiou & M Hudyma (eds), Proceedings of the Ninth International Symposium on Ground Support in Mining and Underground Construction
, Australian Centre for Geomechanics, Perth, pp. 75-84.
In most of today’s underground mines, ground support monitoring is mainly conducted through using microseismic sensors, LiDAR, extensometers, cameras, or visual inspection. These monitoring tools are complementary in nature. Due to high costs associated with purchase, installation, maintenance and utilisation, they are usually deployed or used at sparsely selected critical locations, some of them on a noncontinuous basis. This means that some important pieces of information on ground support conditions may be missing either location-wise or time-wise.
In the last four years, the Energy, Mining and Environment Research Centre of the National Research Council Canada (NRC), in collaboration with CanmetMINING of Natural Resources Canada (NRCan), has developed next generation ultrasound rockbolt sensors (RBSTM) for monitoring load change and deformation experienced by rockbolts. Intrinsically low costing and installation onto exposed end of rockbolts using production bolters, the technology is meant to be deployed on a large number of rockbolts whereby the instrumented rockbolts become a network of ground condition sensors to provide on-demand 3D mapping of ground stress change and deformation all over excavated zones. Field trial data collected in a production mine has demonstrated that monitoring a cluster of rockbolts can provide much more meaningful and reliable information about ground condition when compared with information provided by a single instrumented rockbolt. Therefore, monitoring clusters of rockbolts is recommended as being an effective practice for ground support monitoring.
Keywords: rockbolt sensor, RBS, rockbolt inspection, rockbolt monitoring, rebar bolt monitoring, bolt elongation monitoring, bolt load monitoring, ultrasound, ground support mapping