Forecasting Catastrophic Rupture in Brittle Rocks Using Precursory AE Time Series

Abstract An evidently precursory acoustic emission (AE) time series, characterized by a time‐reversed Omori law, is registered prior to the unconfined catastrophic rupture of brittle sandstone. This provides insights into the physical process controlling catastrophic rupture and underlies the failure forecast. The onset of acceleration of damage is first identified based on the acousto‐optical characteristics. The precursory time series of rise time (RT) rate is used to forecast pseudo‐prospectively the catastrophic rupture in the framework of the time‐reversed Omori law. Investigations on multiple unconfirmed failure cases on the laboratory scale show that forecasts become more precise and less biased as the precursory AE time series proceeds toward rupture. In contrast to retrospective forecast, pseudo‐prospective forecast obtains a higher quality. Moreover, the use of amplitude as a precursor benefits the increase of warning time, and the flaw‐to‐flaw interaction introduces a strong disturbance on the forecast.