Secondary Development and Application of Roadway‐Bearing Model Based on Residual Strength of Deep Fractured Rock

This study focuses on addressing the challenge of supporting deep crushed rock roadways in the Ping Mine. It includes a structural model, numerical calculations, field tests, and other methods to investigate the distribution range and stress behavior of both the crushed zone and plastic zone under unsupported surrounding rock conditions. The underlying cause of the original support system’s failure has been identified. The study results have shown that the roadway exhibits characteristics of a typical deep broken rock roadway, with sequential formation of a broken zone, plastic zone, and elastic zone in the surrounding rock after excavation. Stress discontinuities are directly evident in both the crushing and plastic zones, caused by differences in cohesion and friction properties between them. A modified FLAC3D model, based on the Mohr–Coulomb model, has been developed to automatically reduce cohesion and friction angle as surrounding rocks yield. The new model has been successfully applied to uniaxial compression testing and roadway support simulations, with results aligning well with actual observations and theoretical solutions. On‐site monitoring has confirmed that the adopted support scheme effectively controls behavior surrounding rocks, with no occurrence of malignant expansion or nonuniformity within these zones. Overall, the original support scheme has been optimized based on analysis of crushed zone distributions, and effective control over the behavior surrounding rocks has been achieved through the implementation of a support scheme, resulting in no occurrence of malignant expansion or nonuniformity within these zones.