Mining Causes Rock Movements
LKAB monitors and makes forecasts regarding how mining operations will affect not only rock movements down in the mine but also the surface.
Land deformations are monitored by means of measuring plinths and GPS technology. Kiruna has erected 333 survey plinths in Kiruna and 226 in Malmberget. Their readings are compared to the deformation conditions established by the Swedish Environmental Court of Appeal and are reported quarterly to the authorities concerned.
LKAB also performs underground monitoring of how mining affects bedrock. LKAB has installed the world’s biggest microseismic facilities in Kiruna and Malmberget to measure rock movements. The system in Kiruna currently comprises 133 geophones, and there are 140 in Malmberget.
Every major event is analyzed and the surrounding areas are assessed and inspected by rock engineers who document the events in special reports. The information is disseminated both internally and externally via such media as this website. The measurements and analyses are later used in making forecasts about rock stability, and to issue recommendations about rock reinforcement measures.
Rock reinforcement has high priority and is an important underground safety aspect. LKAB collaborates with LTU and Boliden in a Vinnova-financed rock reinforcement project to increase understanding of dynamically loaded reinforcements and weak rock reinforcements. LKAB is also participating with e.g. Boliden, Vale Inco and Barrick in a collaborative project concerning rock reinforcement in mines led by Rock Tech Centre (RTC).