Characteristics of stress distribution and failure mechanisms in roadway surrounding rock under stress path effects

The direction of principal stresses exerts a significant influence on the plastic failure patterns of roadway rock masses. This study establishes a mechanical model for roadway rock masses, derives corresponding stress functions, and reveals the deformation failure mechanisms of roadway rock masses using maximum and minimum principal deviatoric stresses as evaluation criteria. Building upon this foundation, a deviatoric stress distribution function accounting for principal stress rotation is proposed, alongside the establishment of corresponding plastic failure equations. The research findings indicate: (1) Principal stress rotation induces synchronous rotation of the internal oblique stress field within the rock mass, without altering its inherent distribution pattern or magnitude; (2) Under high oblique stress conditions, the plastic failure zone rotates synchronously with the oblique stress. Although principal stress rotation does not significantly alter the overall morphology of the plastic zone, it repositions the failure area, thereby inducing asymmetric failure of the rock mass. Taking the 31,303 return airway as an example, high-intensity mining activities subjected the surrounding rock to high oblique stress rotation. Addressing its asymmetric failure characteristics, a combined control scheme of ‘asymmetric bolted cable support + borehole pressure relief + advance shielding roof support’ was proposed, demonstrating favourable field application results.