Rock layer deformation analysis and mitigation at fault-crossing mining sites in RCRM operations

When dealing with cross-fault mining operations, geological faults pose significant challenges to by unsettling the existing stress conditions, causing lopsided deformation of the surrounding rock, sudden shifts in displacement, and creating hazards such as fault slippage that really hinder the application of the application of Roof Cutting and Retaining by Mining technology. Drawing upon the 11,101 working face at Qipanjing Coal Mine as its foundation, this research brings together theoretical analysis, finite element modelling, and field verification to get to the bottom of the complex dynamics at play. Based on key stratum and voussoir beam theories, a three-stage mechanical model for fault-crossing mining was established. Drawing upon fundamental stratum mechanics and voussoir beam theory, researchers formulated a three-stage mechanical framework for mining across fault lines. This model demonstrates that advanced stress initially plummets as a result of the "fault stress barrier effect" before gradually rebounding once the working face withdraws from the immediate vicinity. Using the double-yield model to simulate caved gangue characteristics, and introducing deviatoric stress to compare three slotting heights, the study found that higher slotting heights reduce surrounding rock distortion energy and compressive deformation intensity, with 10 m achieving optimal economic efficiency (peak deviatoric stress invariant reduced by 24.8 MPa2, overlying strata displacement by 0.11 m, fault displacement by 0.04 m). A "slotting + loose blasting" scheme was proposed. On-site verification showed it cuts hydraulic support force by 15.3% and gangue bulking coefficient by 4.3%, providing technical support for RCRM application in fault-developed areas.