Failure analysis of water-bearing sandstone using acoustic emission and energy dissipation

We performed uniaxial compression tests on sandstone with variable water contents (dry, natural, and fully saturated) and monitored deformation and failure in real-time using acoustic emission (AE) techniques. We propose sandstone damage variables on the basis of accumulative AE energy and dissipated energy theory. The results provide a useful framework for evaluating rock failure and structural design of rock engineering to improve service life. The peak strength of sandstone in the natural and saturated state is 18.75% and 51.70% lower than that in the dry state, respectively. The stress-time results show a gradual change of the sandstone deformation mode from brittle to ductile with increasing water content. The AE data are closely related to crack compression and formation and the propagation and evolution of new fractures, which reflect the sandstone's internal damage. Increasing water content also shows a clear influence on accumulate AE energy but does not affect the strong increase prior to damage. The damage variables can accurately reveal the evolution of rock damage during compression.