Investigation of Stability of Roof Rocks Treatment Workings of Placer Deposits Solur
The paper considers evaluation of the stability of the roof rocks treatment workings in underground mining of placer deposits. The authors show the geological characteristics of diamond deposits Solur, describe the properties of the rock mass overlying, underlying rocks and productive formation. It was investigated the preliminary assessment of the roof stability by Z. Bieniawski (RMR - Rock Mass Rating) and D. Lobshir methods (MRMR - Mining Rock Mass Rating). The paper brings the calculations for determination of stability of roof rocks treatment workings of diamonds placer deposits Solur by D. Lobshir’s rating classification, which has been widely used to date in matters the roof stability of the rock mass. The results of calculations performed for conditions of overburden rock, bedding rock and producing formation of diamond deposit Solur. The summary table shows the calculation results of the rating conditions for MRMR productive formation and enclosing rocks of the deposit. According to the results of the rock mass rating calculation by D. Lobshir’s geomechanical classification for conditions of diamond placer Solur there were defined the stability class of roof rock and development system with the establishment of stope ore passage.