• Unconventional asymmetric failure in mining roadways is primarily driven by the angle between roadway axis and maximum horizontal stress, causing uneven principal stress distribution.
• On-site measurements in the 9106 ventilation roadway revealed coal sidewall deformation of 50–80 cm and failure zone depth up to 3 m, significantly exceeding the coal pillar side.
• A novel stress analysis model was developed to quantify the combined effects of in-situ stress and mining-induced stress on roadway surrounding rock.
• True triaxial tests demonstrated that differential stress distribution exacerbates crack propagation and fracture on the coal side, providing a mechanical basis for UAF.