METHOD OF DETERMINING CHANGE OF STRESS STATE OF ROCK MASS IN VICINITY OF WORKING Russian patent published in 2014 - IPC E21C39/00 G01N29/14 

FIELD: mining.

SUBSTANCE: invention relates to mining and is designed to determine the change in the stress state of the rock mass. The method comprises placement in the well of the hollow cylindrical acoustic line, receiving and analysis of parameters of ultrasonic signals propagating in it by means of the acoustic emission transducers mounted on its end surfaces. Preliminarily on the acoustic line coaxially with it and at some distance from each other at least two rings of textolite are fixed, which inner diameter coincides with the diameter of the acoustic line, and the outer - with the well diameter. Deformation of the well due to the shift of the reference pressure zone, results in deformation of the respective textolite rings and, respectively, the growth of acoustic-emission activity in these discs. The difference in time of arrival to the receiving transducers of those acoustic emission signals is measured, the amplitude of which is maximum of all incoming signals, and the depth of the zone of the reference pressure and its change in time is judged by the above mentioned time difference, the known length of the acoustic line and the measured rate of propagation of ultrasound in it.

EFFECT: increase in duration of the definition of changes in the stress state of rock mass in the vicinity of working during continuous monitoring acoustic-emission measurements of movement deeper into the solid mass of the zone of reference pressure.

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