Analysis of mechanical properties and failure modes of single-fracture water-bearing sandstone under different dynamic disturbances

Abstract

In the intricate geological milieu of deep mining areas, the interplay of water and fractures profoundly diminishes the stability of the surrounding rock, rendering it more susceptible to disturbances engendered by mining operations. This process triggers cumulative damage and initiates dynamic hazard failures, thereby compromising the stability of mine tunnels. The present study investigates the mechanical properties, energy dissipation, and evolution of failure modes of water-bearing single-fractured sandstone under dynamic disturbances of different amplitudes. The results indicate that: (1) Increased water content significantly reduces the compressive strength of sandstone, heightening its sensitivity to disturbances. (2) Across increasing disturbance amplitudes (1–5 MPa), sandstone exhibits significantly higher dissipation energy density and accelerated damage accumulation. While its failure mode transitions from tensile to mixed shear-tensile failure. These results provide fundamental insights into instability mechanisms and dynamic hazard control strategies for deep water-rich soft rock mines.