Acoustic Emission in Loaded Sandstone Specimens as a Precursor of Sudden Failure

摘要

An attempt is presented to describe the time distribution of acoustic emission in sandstone specimens subjected to incremental uniaxial compression. It was found that after the ultimate long-term compressive strength is reached, a sequence of impulses occurs which resembles a series of earthquake foreshocks. The obtained empirical function describing the time distribution of AE spacing time intervals enabled to propose a modification of Gu's interpretation method not demanding the preliminary classification of fore- and after-shock categories.