Abstract
Abstract In this paper, a new way of characterizing the mining-driven complex geological deformations is presented by utilizing a continuous real-time microseismic (MS) data acquired through passive seismological monitoring. The data was processed, and the source parameters were computed encompassing over 60,000 MS events. The correlation between MS events and regional stratigraphy reveals that the Upper and Middle Xishanyao Formations substantially contributed to induced seismicity. Most of the high-energy events (>3000 J) are located between 1200 and 1400 m in the coal seams and above, indicative of formation of the macrofracture in the roof rock layers perturbing the limits required for the equilibrium state of roof structure. Taking advantage of the recorded events, a large number of induced fractures are mapped and interpreted associated lineaments and their deformation mechanism is discussed. The correlation of mapped fractures and lineaments with MS energy showed an extremely erratic and complicated pattern revealing the different levels of accumulated stress. Based on the orientation and geometry, regional lineaments were classified into two broad systems that provided guidance for determining the propagation directions of the deformation. Based on the in-depth analysis of fractures and lineaments, a new fault is identified with length>700 m and various splays oriented in different directions serving as a new tool in rock engineering. An upsurged shear stress and decreased normal stress along the fault may lead to enhanced induced seismicity. Furthermore, a total of 5 vulnerable zones are identified as an example offering insights for worldwide geohazard assessments.
Highlights
The understanding of geological complexities and rock mechanical behavior holds an imperative value for the efficient designing of engineering activities and safe exploitation of coal
The geological features triggering microseismic activity can be directly imaged by reflection seismic, whereas the microseismic events observed at Kuangou coalmine present a complex pattern of distribution suggestive of complicated subsurface geology that is not sometimes imaged by seismic reflection
This study suggests a new method for addressing complex geological deformations that resulted during the coal excavation process
Summary
The understanding of geological complexities and rock mechanical behavior holds an imperative value for the efficient designing of engineering activities and safe exploitation of coal. In industrialized countries such as China and the United States, the importance of the regional geological understanding of the mine environment has led to vast application in coalmine operations for the recognition of unstable underground geological conditions (mine hazards). This strategy has remarkably helped in reducing fatalities and injuries and economic as well as production loss [3]. The worldwide historic dynamic geological disasters reported in rock engineering include rock burst, gas outburst, collapse, landslide, subsidence, debris flow, unstable slope, and ground fissure [4, 5]. Rock burst is an abrupt violent failure of rock strata causing release of huge elastic strain energy as a direct manifestation
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