The coal mining under the goaf of close-up room mining coal pillars is prone to chain instability and damage of the overlying coal pillars, aquifer damage, surface subsidence, soil erosion, vegetation withering, and other problems. In this paper, theoretical analysis was conducted on the stability of the remaining coal pillars in room mining, and numerical simulations were used to study the influence characteristics of the plastic zone, strain energy, and stress field of the overlying coal pillars during the mining of the lower close coal seam. The stability of the coal pillars under the influence of mining was analyzed with the safety factor. The proposed technologies of cemented paste backfilling on the ground and backfilling the goaf of the lower coal seam are applied, the influence of different water-cement ratios, aeolian sand, and cement content on the mechanical properties of backfilling materials was studied through experiments, and the stability of overlying coal pillars with different dimensions of the backfilling pier columns under certain ratio conditions was studied using numerical simulation method. The research results indicate that when the dimensions of the backfilling pier columns are 40 m x 40 m and the compressive strength is 3.12 MPa, the stability of the overlying coal pillar can be effectively controlled, achieving safe mining under the remaining coal pillar. The research results can provide new ideas for the mining of coal resources and environmental protection under the remaining coal pillar of room mining.

来源平台：APPLIED GEOPHYSICS