Document Type
Conference Paper
Publication Date
2-2016
Abstract
Although the room and pillar mining method is world-known and widely used, in terms of the Czech coal mines located in the Upper Silesian Coal Basin it is still in the testing phase. Unfavourable mining, geotechnical conditions at large depths and the ban by Czech mining authorities prevented this method from being used on rock bolt reinforcement without other roof support. Typically, large amounts of unexploited coal reserves are left in the shaft protective pillars. This coal can be mined if strata subsidence is minimised. Due to its low subsidence characteristics the room and pillar mining method without pillar extraction has been trialled at the CSM Coal Mine at the end of 2014. During the pillar development phase complex geotechnical monitoring was undertaken including the frequent scanning of pillar movement using 3D laser scanning technology. The laser scanner enabled complex capture of the entire space around the monitored pillars during the period of pillar formation and afterwards. The time-lapse scanning method measured changes in the mine roadway surface profiles including pillar displacements, roof movements, floor heave and other dynamic phenomena. The time-lapse scanning indicated variable pillar rib movement ranging from a few cm to a maximum of 50 cm with an average of approximately 25 to 30 cm. The scans indicated that the bottom of the seam displaced more than the top of the rib side due to large floor heave. The weak floor consisting of siltstone and coal beds experienced large floor heave however, due to floor brushing no reliable floor displacements are available. In contrast to the large movements in the rib and the floor, the strong roof strata did not show any significant movements. The purpose of this work is to highlight the importance of terrestrial laser scanning as an essential engineering design tool to evaluate the displacements and deformations of mine excavations at large depths. The 3D scanning results gave relevant information about displacements and deformations that occurred at the tested site and thereby helped to improve safety underground.
Publication Details
Radovan Kukutsch,Vlastimil Kajzar, Petr Waclawik and Jan Nemcik, Use of 3D Laser Scanner Technology to Monitor Coal Pillar Deformation, in Naj Aziz and Bob Kininmonth (eds.), Proceedings of the 16th Coal Operators' Conference, Mining Engineering, University of Wollongong, 10-12 February 2016, 99-107.