Estimation of Rock In-situ Stress by Acoustic and Electromagnetic Emission

Estimation of Rock In-situ Stress by Acoustic and Electromagnetic Emission

Peer-reviewed article not indexed in WoS or Scopus

The Kaiser Effect in acoustic emission is often used fpr an estimation of the stress to which rocks have been subjected. However, there are case in ehich the Kaiser Effect is not clear, since the noises due to contact and/or the stick slip between the pre-induced fracture surfaces are measured during loading processes. In such cases, estimationof previous stress uis difficult by the conventional method which is based on acoutic emission activity observed under loading process. In the test for the Kaiser Effect on rocks, therefore, the noises must be eliminated from the acoustic emission generated from newly created cracks during the second loading process. Such techniques as analysis of the difference between the acoustic emission activity observed in the fiorst and second reolading and the analysis of the change in sthe slope of the acoustic emission amplitude distribution have been proposed. In this paper we present a new method by which the maximum previous stress in rocks can be directly estimated without any post signal analysis. In the new method, simultaneous measurement of acoustic and electromagnetic emission during loading test of rock sample is employed.

The Kaiser Effect in acoustic emission is often used fpr an estimation of the stress to which rocks have been subjected. However, there are case in ehich the Kaiser Effect is not clear, since the noises due to contact and/or the stick slip between the pre-induced fracture surfaces are measured during loading processes. In such cases, estimationof previous stress uis difficult by the conventional method which is based on acoutic emission activity observed under loading process. In the test for the Kaiser Effect on rocks, therefore, the noises must be eliminated from the acoustic emission generated from newly created cracks during the second loading process. Such techniques as analysis of the difference between the acoustic emission activity observed in the fiorst and second reolading and the analysis of the change in sthe slope of the acoustic emission amplitude distribution have been proposed. In this paper we present a new method by which the maximum previous stress in rocks can be directly estimated without any post signal analysis. In the new method, simultaneous measurement of acoustic and electromagnetic emission during loading test of rock sample is employed.

Kaiser Effect, rock stress, electromagnetic emission

Kaiser Effect, rock stress, electromagnetic emission

MORI, Y.; SEDLÁK, P.; ŠIKULA, J.

19.09.2006

1022-6680

Advanced Materials Research

2

13-14

Swiss Confederation

357

6

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