Dynamic Deformation and Failure Characteristics of Deep Underground Coal Measures Sandstone: The Influence of Accumulated Damage

Understanding accumulated damage effects is essential when undertaking deep underground rock engineering, as complex in situ environments and intense engineering disturbances realistically affect the physical mechanical properties of rocks. Accumulated mainly causes extension micro-cracks sprouting specific defects rocks, altering microstructural parameters. In this investigation, loading unloading tests were used to simulate states coal measures sandstone. The factor was formed by combining P-wave energy variables. effect on bearing capacity deformation behavior sandstone particularly pronounced after experiencing impact loading. experimental results demonstrate that can depict initial state well subsequent dynamic progressive damage. There a mutually governing between strain rate. contrast, significantly extends range rates, which fed back into uniaxial compressive strength negative correlation fracture damage, strongly agrees with sandstone’s mechanism. combination loads be assess long-term safety engineering.