Study of the Failure Mechanism of Soft Rock Mining Roadways Based on Limit Analysis Theory

To study the deformation and failure mechanisms of soft rock mining roadways, 1506 return airway Anyang Coal Mine is taken as engineering background. Based on limit analysis theory, a model based rigid slider system constructed to assess surrounding roadway. The formulas for calculating self-weight power in velocity discontinuity line roadway, work pressure, energy dissipation rate are derived, upper objective function height obtained. characteristics fracture evolution process under different stresses analyzed by means physical similarity simulations. simulation results show that shear occurs first roadway side due stress concentration. fissures expand along bottom angle blind support area low-intensity area. cracks weaken strength angled anchor cable bolt shoulder. Under action roof status mass inside outside slip zone changes from static dynamic. This causes roof, side, floor.