With the massive mining of coal resources, coal mining under special conditions such as “Coal mining under buildings and railways and water-bodies” thick coal seams has became a key concern for relevant scholars. As a mining method to effectively replace “Coal mining under buildings and railroads and water-bodies” thick coal seams, paste backfilling is an important part of the coal green mining system. In this paper, by combining theoretical analysis, numerical simulation, and other means, the migration law of overlying rock in paste backfill mining of continuous mining face in thick coal seam upwards under the village was studied. FLAC3D numerical simulation software is used to analyze the upward separation of thick coal seams. Surface subsidence was simulated at each stage of paste backfill mining in the continuous mining face, and the influence of the backfill elastic modulus on the overburden subsidence, the backfill and coal stress, the range of the overlying plastic zone, and the surface deformation was simulated and analyzed. The elastic modulus of the filling body was finally determined.

During excavation in a deep tunnel, dynamic disaster is an extremely severe impact failure. The necessity of an energy-absorbing support system is analyzed for different characteristics of dynamic disaster (rockburst) failure. The energy-absorbing support system design includes a combination of early-warning, energy-absorbing bolts, and other components. This support system is designed to meet the energy requirement of a rockburst disaster based on an early warning. The energy-absorbing rockbolt uses the stepwise decoupling technique to realize the brittle-ductile transition of the structure, which is referred to as a stepwise decoupling rockbolt (SD-bolt). The ultimate force, ultimate deformation, and energy were calculated as 241 kN, 442.3 mm, and 95.89 kJ under static pull-out load. Monitored by a microseismic system, the support system was tested by moderate rockburst disaster impact on site. Considering similar rockburst disaster failure cases, this energy-absorbing support system can reduce rockburst disaster damage to a certain extent and improve overall safety during deep engineering construction.

The key to cementation backfilling in underground stopes of metal mines is quality and efficiency of backfilling. Backfilling quality is inseparable from the cementitious material as well as the tailings properties. To explore the influence of different factors on the strength of the backfilling body, the ratio of backfilling cementitious materials in the preparation process of backfilling slurry was experimentally studied to determine the economical and reasonable proportion of backfilling cementitious materials. Under the multi-factor test, it is concluded that the proportion concentration of 1:6 and 66% in the cemented specimen of medium and fine tailings meets the strength requirements of the surface layer of the backfilling body. Using the numerical simulation software FLAC^3D, the movement of rock mass under different backfillings is simulated, and the subsidence of overburden, the stress of the ore body, and the damage range of the plastic zone are analyzed. The results showed that, during the transition from full tailings cemented backfilling to medium-fine tailings paste backfilling, the vertical stress concentration area of the overlying strata shifts from the surrounding ore body to the backfilling body, the plastic zone decreases, and the complexity of failure forms gradually decreases. Finally, the transformation method from full tailings cementation backfilling to medium fine tailings paste backfilling is determined, and the medium fine tailings paste backfilling in a deep gold mine is realized.