IM 2019 August 19 | Page 67

SLOPE STABILITY MONITORING mining companies around the world to disclose detailed information on their tailings dams facilities. David Noon, GroundProbe COO told IM: "GroundProbe is proud to have been brought in to help to monitor tailings dams at several highly- publicised sites in Brazil which experienced significant tailings failures in recent years, including the Samarco Mineração SA tragedy that occurred in 2015. Despite not being on-site before or during the collapses, GroundProbe systems were brought in to monitor the continued stability of the dams moving forward for maximum safety. GroundProbe radars and lasers are now also monitoring a number of tailings dams in a precautionary capacity, as sites commonly do for their open cut slopes." Some dams were deemed high risk with assumed instability, so monitoring regimes were put in place to monitor the movement and predict if and when a failure was likely to occur. Other sites have deployed monitoring systems because of a hypothetical risk to the dam. "The hypothetical risk or consequence classification doesn’t take into account the actual stability of the dam, but rather the risk should the dam collapse. Dams are classified according to: the potential loss of life; environmental, cultural and social impacts; and infrastructure and economic losses." Each tailings dam is unique and so is the consequence of failure should the dam collapse. The size and volume of the dam, the type of material it holds, its method of construction and consequence classification, as well as the site’s geography and climate, should all be considered when determining the level of monitoring required. "GroundProbe believes the level of risk control required and the site’s specific monitoring needs should correspondingly determine the monitoring solution required. GroundProbe provided one such solution to Samarco Mineração SA who purchased two safety-critical, mobile radar systems (SSR-XT) and three long-range, fixed-deployment radar systems (SSR-SARx) to monitor their Santarém and Germano dams, following their dam collapse in 2015." Whether post-failure or as a precautionary measure, GroundProbe is deploying both radar and laser technologies to the dams, and sites are commonly also employing its Geotechnical Support Services (GSS) remote or local monitoring services. “The GSS team are able to provide customers with dedicated 24-hour remote monitoring solution for mine sites anywhere around the globe. The remote monitoring team, all fully-qualified Geotechnical Engineers with extensive radar knowledge and experience, operate 24/7 from a central, remotely-located office. Providing real-time support, the team monitor live radar data and respond to alarms and movement, remaining in close phone and online contact with site-based staff." GSS can be used to provide additional training as well as customised report generation. The reports include detailed data analysis and interpretation of data, and can be produced as often as required. GroundProbe also provides hardware and software training on-site upon deployment and further supports our users through a 24/7 support desk and an online database of training manuals accessible for all its customers. Noon says the company has deployed monitoring solutions to tailings dams across the globe, including Brazil, Australia, Chile and South Africa. Maptek helps ensure safe operations at Broadmeadow BHP Coal's Broadmeadow Mine is one of only a few punch longwall mines in Australia. This method makes use of abandoned open cut mine strips and drives gateroads directly into the seam at the base of the highwall, with no requirement for main entries. The longwall is then retreated towards the open cut and recovered just short of the highwall, leaving a safe barrier pillar. Broadmeadow has mined 11 longwall panels by this method, from two adjacent open cut strips. Significant highwall movement was related to the effect of subsidence when longwalls approach their final position close to RIEGL VZ-2000i for TOPOGRAPHY AND MINING high-accuracy h hig ig gh acc gh-acc RIEGL VZ-2000i scan data Long Range, Very High Speed 3D Laser Scanning System » RIEGL LiDAR Waveform Technology for high accurate data (5 mm) » rapid data capture with up to 1.2 million measurements/sec » extensive coverage with up to 2500 m range » smart operation by remote scanner control and onboard software apps » outstanding efficiency through automatic onboard registration capabilities, customizable workflows, and connectivity via LAN, Wi-Fi, 3G/4G » for topography and mining: surface modeling, toe & crest line extraction, change detection, cut & fill volume calculation, and slope gradient angle control VISIT US AT September 17-19, 2019 | Stuttgart RIEGL booth I1.024, hall 1 Stay connected with RIEGL www.riegl.com RIEGL LMS GmbH, Austria | RIEGL USA Inc. | RIEGL Japan Ltd. | RIEGL China Ltd. | RIEGL Australia Pty Ltd. AUGUST 2019 | International Mining 63