Whole-Area Pressure Relief Characteristics of Roof-Cutting and Pressure-Relief Technologies in a Mining Field

As an effective measure for optimizing stope stress, roof cutting and pressure relief has been widely implemented in underground mining. Diverging from previous studies focusing on roof-cutting techniques, this research aims to elucidate the whole-area stress-relief characteristics induced by roof-cutting and pressure-relief technology and the collapse behavior of goaf. A mining model was constructed using FLAC3D numerical simulation software to investigate the effects of roof cutting on surrounding rock movement and pressure-relief characteristics before and after mining. The results show that before mining, roof cutting reduces the maximum stress on the roadway roof by approximately 54%, the average stress by 33%, and the average coal stress beside the roadway by 20%. After mining, the maximum stress on the goaf roof on the roof-cutting side is reduced by 12%. No significant pressure-relief difference is observed along the strike direction. Vertically, the roof’s maximum stress decreases by 11%, the maximum coal stress beside the roadway is reduced by approximately 18%, and the average roof stress decreases by about 50%. The caving range of the goaf expands by 16 m along the dip direction, and the pressure-relief range increases by 26 m. Roof cutting produces a significant pressure-relief effect and enlarges the effective caving area within the goaf. This study elucidates the pressure-relief and caving characteristics under roof-cutting mining, providing a theoretical foundation for roadway support design and goaf flow field analysis.