Abutment Pressure of Main Roadway Coal Pillars in Close-Distance Seam Mining Considering Stress Superposition

In close-distance coal seam mining, the stability of main roadway pillars is critically influenced by stress superposition from overlying remnant pillars. This study develops a theoretical model that integrates elastic foundation beam theory with the Boussinesq solution to evaluate the abutment pressure of the lower coal pillar under the combined effect of self-weight and additional stress transferred from the upper seam. The model accounts for three typical pillar spatial configurations—outward-staggered, inward-staggered, and vertically aligned—to capture the influence of layout patterns on stress redistribution. The proposed approach is validated through numerical simulations, and the results reveal distinct stress distribution characteristics under different pillar arrangement conditions. The findings provide a theoretical basis for optimizing stagger distances and pillar layouts to ensure long-term stability of main roadways in multi-seam mining.