Short-wall roadway backfill method for sustainable mining

It is crucial to control surface subsidence and utilize solid wastes for sustainable mining. This paper proposes a short-wall roadway backfill mining method with advantages in avoiding surface subsidence and utilizing solid wastes. A mechanical model is developed to predict roof fractures based on tensile stress. The impact of mining parameters-such as mining height, working face length, and backfill mechanical properties-on roof stress distribution is examined. Further, a case study in a Chinese coal mine is carried out to determine the preliminary mining parameters using the analytical model. Numerical simulations then explore stress and deformation characteristics, followed by monitoring rock strata stability under the proposed mining conditions. Results show the backfill's elastic modulus is the primary factor affecting the tensile stress of the basic roof beam. With the elastic modulus increasing from 0.45 to 0.5 GPa, the maximum tensile stress reduces by 2.38 MPa. A suitable backfill materials mixture for the coal mine is further determined. Numerical simulations show that the main load-bearing structure shifts from the coal body to the backfill body, with surface subsidence remaining within acceptable limits for building safety. Field application and monitoring prove that roof movement and surface subsidence are well controlled by using the developed method.