Innovative Approach to Monitoring Coal Pillar Deformation and Roof Movement Using 3D Laser Technology

摘要

Monitoring of pillar and roadway deformations is one of the most important issues in geotechnical engineering and mining practice. The use of 3D laser technology is ideal to monitor strata displacements in underground excavations enabling complex spatial data capture of the entire space around monitored pillars including all roof and rib deformation which occurs during the pillar excavation. This method based on repeated scans, can monitor the excavation surface movement ranging from a few mm to more than 600 mm. The 3D laser scanner was used to monitor the coal mine roadways and pillar stability in room and pillar panel trial in the Ostrava-Karvina coal basin (OKD Mines, Czech Republic). The 3D data analysis indicated rib movement that ranged from 250 mm to more than 600 mm, a large floor heave that was regularly brushed and practically no roof movement of very strong roof strata overlaying the whole panel area. All scanned results compared well to the results from the extensometry and other measuring instruments. The results further indicated that the mined roadway cross sectional area decreased between approximately 15-25 % during the first 7 months of monitoring and stabilized at 5 % after another 7 months. Further monitoring is planned to identify any long term creep in the room and pillar panel.