The rock fracture experiment with a drive control: A spatial aspect

The statistical analysis of the space-time distributions of acoustical signals emitted from the compressed samples of Westerly granite is presented. The samples were uniaxially loaded in two regimes, one of which included a feedback loop controlled by the current acoustical emission (AE) activity. The distribution of distances between newly-appeared hypocenters follows the power law with the exponent that does not depend on the mode of loading. In both regimes, a transient period of the decorrelated accumulation of damaged sites was revealed between the initial and focal stages of the fracture process. The Hurst analysis indicates a more pronounced trend to planar organization of final damage structure in the case of AE-controlled loading.