Stability assessment of adjacent rock mass in the development of coalbed outlets

The problems of stability assessment of the quarry’s southern side during the development of the coal seam D6 are considered. To assess the stability of the quarry’s southern side in the development of coalbed outlets, modern research methods are applied: study of the geological structure and analysis of the adjacent rock mass state, the creation of an observation station and the production of observations, calculation of stability of adjacent rock mass of the quarry’s south side and the research results analysis. Quarry’s south side consists of clayey sediments up to 5 m, then siltstones and mudstones up to 1020 m and a coal seam with a capacity of up to 5 m. The substantiation of the calculated strength characteristics of rocks composing the slopes of the quarry ledges, which determine the stress state of the slopes arising under the influence of internal and external forces, is done. Instrumental observations of the laid station and the survey of cracks on the quarry’s side allowed to determine the contours of the deformation zone and the landslide prism size. A geomechanical model of adjacent rock mass was created and the stability assessment was carried out for the geological section along the line of the maximum development depth. After additional loading on the quarry’s southern side slopes, the safety factor of stability is nу = 1.69-173, which means active phase termination of quarry’s side deformation and sustainable condition.