Asymmetric Deformation and Stability Control of the Roof Plate of a Return Mining Roadway Through a Normal Fault

Fault structures near underground coal mine return roadways frequently influence the deformation of surrounding rock, thereby constraining roadway stability. However, when the roof deformation is not clear in the case of a roadway through a normal fault, it will directly affect the establishment of a reasonable control program for the roof. Based on elastic-plasticity theory, this paper proposes a method for calculating the maximum deformation position of the roof plate in a roadway through a normal fault. This method accurately determines the maximum deformation position while considering the variation in widths between the upper and lower roof plates. Numerical simulations revealed the dual characteristics of asymmetric deformation in the roof plate and the asymmetric morphology of the plastic zone during the mining period. Furthermore, it delineated the significant impact of the width of the roof plate of the lower disc on roof deformation. A statistical analysis was conducted on the standard deviation (S) and coefficient of variation (CV) of both the theoretical and numerical simulation results, as well as the error rate between them. The analysis responded well to the reliability of the study results. The proposed reinforcement support program effectively guided the stability control of the roof plate in the roadway through the normal fault at the site. The research findings provide valuable insights for predicting and controlling roof deformation in roadways and tunnels under similar engineering conditions.