Full-space collaborative support technology for reconstructing multi-bearing structures in crushed soft rock roadways under strong dynamic pressure

This is the authors' abstract. We don't add key points for this paper.

To address the challenges posed by complex regional stress and the maintenance of surrounding rock in soft rock roadways subjected to strong dynamic pressure crushing during excavation, this study focuses on the 1570 track stone gate of Daniuchang Coal Mine in Guizhou Province as the engineering context. A comprehensive research approach was employed, utilizing numerical simulations, theoretical analyses, and on-site industrial tests. Through on-site investigations and data monitoring, we analyzed the large deformation of the surrounding rock at Shimen on the 1570 track and the failure characteristics of the supporting components. The poor self-stability of the surrounding rock was investigated using water immersion tests (combined with XRD analysis) and loose ring tests. Numerical simulations were conducted to elucidate the stress distribution patterns during the excavation of the 1570 track stone gate, revealing its deformation and failure mechanisms. We specifically proposed a full-space collaborative support technology for the reconstructed multi-bearing structure. The ultimate bearing stress of the most critical section of the concrete steel arch frame was derived through theoretical analysis, confirming that the constrained steel pipe filling structure could effectively limit the significant structural movements induced by mining activities. The stress distribution and deformation control effects of the surrounding rock in the reconstructed multi-bearing structure were analyzed through numerical simulations, clarifying the control principles underlying the full-space cooperative support technology. By constructing a three-layer high-strength load-bearing structure, we integrated the shallow and deep surrounding rocks into a cohesive high-strength anchor solid load-bearing system. This approach harnesses the surrounding rock′s inherent load-bearing capacity and enhances the overall anti-deformation capability of the surrounding rock, thereby establishing a full-space three-dimensional support system that ensures roadway stability. Subsequent industrial tests conducted underground demonstrated that the full-space collaborative support technology for multi-bearing structures significantly mitigates deformation in roadways facing strong dynamic pressure crushing and soft surrounding rock. Compared to the original support system, the convergence of the top and bottom slabs of the roadway, as well as the two sides, was reduced by 91.67% and 88.33%, respectively. Additionally, this approach led to savings in roadway maintenance costs, providing an effective solution for managing surrounding rock in soft rock roadways subjected to strong dynamic pressure crushing.