Laboratory study of the fracturing of rock samples under the long-term controlled deformation and loading

The proposed research project is aimed at studying the process of rock fracturing in a regime of controlled speed of deformation and a regime of controlled stress during long-term sample loading. The project's starting point consists in a knowledge concerning stress-strain properties of rocks from the ultradeep Kola borehole, plus experience from a study of the process of rock fracturing by means of the statistical methods analyzing sequences of ultrasonic emission. Envisaged research into rock fracturing will proceed from determination of the mechanism of microcracks. Experiments will last from tens of hours up to first hundreds of hours from the onset of loading until final failure. A comparison of the fracturing of analogues of mantle-derived rocks with those in the upper crust may yield new findings on the impact of paleostress on the rock material's ability to accumulate and release energy during brittle fracturing. In methodological terms, the study of rock deformation will