Research on roof damage and high-strength reinforcement in deep large-section mining roadways

To address the challenge of controlling roof stability in large-section longwall mining roadways of deep mines, this paper establishes a roof mechanical model, derives a calculation method for the bearing capacity of bolted support systems, designs a novel high-strength grouted anchor bolt, and proposes a synergistic control strategy of “single-stage support with deep anchoring and shallow grouting.” The results indicate that roof stability is primarily governed by two key factors: the rock tensile strength (internal factor) and the support strength (external factor). The bearing capacity of the bolt support system increases with enhanced rock mechanical parameters but significantly weakens as bolt spacing increases. The newly developed high-strength grouted bolt, based on the aforementioned mechanism, combines high pre-tensioning anchoring with grouting reinforcement. Field tests demonstrated that it reduced surrounding rock deformation to 42.2% of the original support scheme, significantly enhancing overall roof stability.