Ravindu Goonawardene
Geology and Geotechnical Superintendent, Anglo American – Grosvenor Mine
Chris Crosby
Surveying Superintendent, Anglo American – Grosvenor Mine
The risk of fatalities due to roof and rib failures is still prevalent in underground coal mines which highlights the fundamental importance of monitoring roof and ribs in underground roadways. Monitoring strata deformation and convergence in underground roadways is a key metric for measuring instability of excavations. Visual inspections, telltales, extensometers and instrumented bolts are some of the methods used to quantify strata deformation.
The significant limitations of the current methods only provide a point-measurement along the roadway. Using laser technology allows the mine to scan and measure large regions of roof and ribs across continuous regions with millimetre accuracy.
The Maptek SR3 laser scanner has been used as a control during the rib optimisation trial at Grosvenor. This technology provides a baseline scan and subsequent scans to ascertain the extent of deformation throughout the active development mining areas. Thus, allowing geotechnical engineers to assess the adequacy of the trialled support system. Moreover, this technology allows geotechnical engineers to better analyse geological anomalies (fault orientations, dips, throw), bolting tolerances and excavation dimensions in an effective manner.
