Study on Optimization of Roadway Layout for Self-Formed Roadways Without Coal Pillars Based on the Mining Influence Mechanism in Close-Distance Coal Seams

This study investigates the roadway layout optimization of self-formed roadways without coal pillars (SFRCP) in close-distance coal seams. By integrating theoretical analysis, numerical simulation, and field application, the mining influence mechanism in close-distance coal seams was revealed, an optimal design scheme for the roadway layout was proposed, and its effectiveness was validated. First, based on the structural characteristics of the stope in close-distance coal seams, a mechanical model for mining stress transmission was established to elucidate the distribution of floor stress induced by the upper stope. Subsequently, the deformation and failure mechanisms of the surrounding rock for SFRCP were analyzed, identifying the key factors influencing roof deformation and coal rib failure depth. These findings formed the basis for proposing an optimal design scheme of roadway layout. Numerical simulations further compared the mine pressure evolution under different layouts, confirming the rationality of the proposed scheme. Finally, field engineering application based on the optimal roadway layout was conducted. Monitoring results confirmed that the surrounding rock deformation met the required safety standards, and the gob-side entry retaining performance was satisfactory. This research provides valuable insights for safe and efficient mining in close-distance coal seams. • The mining influence mechanism in close-distance coal seams was revealed. • The optimal design scheme for the roadway layout of SFRCP was proposed. • The evolution law of mine pressure under different layouts was analyzed.