Spectral characteristics of microseismic emission of coal rock masses of Donbass

Abstract

Introduction: the matter of characteristic spectra of the microseismic emission recorded in the result of monitoring studies in the settlement of Obiedinenny (city of Makeyevka, Donetsk People's Republic), which is located above the Kalinovskaya-Vostochnaya mine, is examined in this article. The results of the analysis of microseismic emission amplitude-frequency characteristics are considered and an assessment of their potential use for predicting the structure of the upper partition of geologic cross-section is made.

The research methodology included: the analysis of microseismic emission amplitude-frequency characteristics. The assessment of rock density distribution by depth was made based on the assumption that the fundamental Rayleigh wave mode amplitude and frequency depend on the rock stratification depth and its density.

 Results and discussion: in the result of the research, it has been established that microseismic emission amplitude distribution by depth differs depending on the microseismic emission components used and on the time of day. It has been established that the spectral characteristics of microseismic emission near a large upthrust associated with significant rock-fracture zones differ markedly from those recorded at undisturbed areas. An assumption has been made that due to stress redistribution in the course of mining operations, an upthrust zone turns into an area of microseismic events reinvigoration related to cracks formation and propagation. Spectral ratios of averaged nighttime and daytime spectra over a long period of time have been obtained. A difference between the spectral ratio structure in the upthrust influence zone and the spectral ratio structures in tectonic no-disturbance zones has been established.

Conclusion: therefore, the research results demonstrated that under the conditions of heavily industrialized built-up areas, the approach basing on the fundamental Rayleigh wave mode amplitude and frequency dependance on the rock stratification depth and density requires being subjected to methodological revision. Analysis of microseismic emission spectral characteristics can be used for detecting rock mass fracture areas associated with tectonic disturbance influence zones.