Failure mechanism of anchorage bearing structure in deep roadway under superposition of dynamic and static loads

Abstract

To investigate the mechanical response of anchorage bearing structures in deep roadways under dynamic loading, a physical simulation test was conducted to analyze the evolution of the strain field under combined static and dynamic loads. A mechanical load-transfer model of the anchorage structure was established, and the key factors controlling instability under dynamic loading were identified. Results show significant stress relief in the roof and floor after excavation. During mining-induced stress loading, localized high-strain zones develop with a peak value of 12,000 με. Blasting disturbance leads to extensive stress release and vertical tensile cracks on the sidewall. Stress waves attenuate most when propagating from soft rock into hard rock. Increasing the pre-tightening force improves stability, shifts the peak tangential stress outward, and deepens the failure zone. Burial depth positively influences the bearing state but has limited effect on the failure location. Higher dynamic load intensity nonlinearly increases rock stress, raising the risk of large-scale dynamic failure. Field practice confirms that optimized anchor cables provide uniform stress distribution, ensuring safe mining operations.