Geomechanical Modelling of the Underground Mining Fastening System’s Parameters for the Kimberlites Deposits Conditions

Considered features of the geological structure of kimberlite deposits of Sierra Leone. In connection with the increase in the depth of the workings, reinforced fastening of the underground part becomes relevant. For a better characterization of the rock mass and design of the support, computer modeling of the upper part of the underground working was performed. The planning of the support system, the choice of materials, the use of anchorage depends on the assessment of the quality index “Q” and the classification of geomechanics for the rock massif was made on the basis of available information about the joints of rocks and their nature. The calculation of fastening with optimization of the thickness of fiber sprayed concrete in accordance with the possible volumes of rock fallout is presented. Recommended support system using modern polymer materials that have a number of economic and technological advantages and can be used in the conditions of kimberlite deposits. Comparative modeling of fastening of the upper part of the underground working using different materials is presented.