Geotechnical roof classification for an underground coal mine from borehole data

It is standard and critical practice in the majority of geotechnical engineering applications to use a rock mass classification system to evaluate the condition of rock in mine planning and operations. The use of geotechnical classification schemes for rock mass characterisation in underground coal mines is well established. Several rock mass classification systems have been developed and used in civil engineering design and for underground mining operations. In the past, these rock mass classification systems were modified and used in the coal mining industry to quantify descriptive geological information for use in coal mine design and roof support selection. To facilitate geotechnical evaluations, mining companies in the Bowen Basin of central Queensland put considerable effort into obtaining geomechanical data from surface exploration boreholes and borecore. The advance or innovation in the proposed method is not in doing the characterisations, but the method of evaluating the required parameters from available borehole geophysics and geomechanical test data. Evaluating radial point-load strength from geophysical correlations is dependent on collating a large comprehensive database of actual point-load test data across the range of lithological types.