Stec, Krystyna (2012) Focal Mechanisms of Mine-Induced Seismic Events an Explanation of Geomechanical Processes in the Area of Longwall 6, Seam 510 In Hard Coal Mine “Bobrek-Centrum”. Archives of Mining Sciences, 57 (4). pp. 871-886. DOI: https://doi.org/10.2478/v10267-012-0057-7
Full text not available from this repository.Abstract
Abstract: Exploitation in a coal mine “Bobrek – Centrum” of the longwall 6 in seam 510 has led to the occurrence of very high seismic activity. From January 2011 to June 2012 took place almost 3500 tremors with the energy of 10^2 – 10^4 J and 95 tremors of energy more than to 10^5 J. In an attempt to identify the character of that seismicity, calculations of focal mechanism parameters were carried out, and according to them local stress field was determined. Three periods of exploitation of longwall 6 were distinguished which vary in type of focal mechanism. Tremors, which occurred in exploitation periods I and III were characterized by normal slip mechanism, occurred due to domination of vertical principal stresses s1, horizontal intermediate stresses s2 and minimal ones s3. Such stress arrangement characterizes local state of rock mass behaviour as a result of cracking and collapse of sandstone, tremor-generating strata during advancing exploitation. In exploitation period II, of non-shearing mechanism of foci occurred. That was the period of change of longwall run from the NE-SW direction to E-W direction, that is the period of so called “slanting” of exploitation front. It can be presumed that this type of tremor mechanism could have occurred due to a sudden coal bed load by superimposed roof strata, which may have led to extreme load conditions and to a dynamic disintegration of seam part. It was confirmed by geomechanical calculations, which indicated that in the region of rockburst existence on 19.07.2011, layers which were located above and under seam 510 in area of longwall no.6 were strongly deformed locally causing compression of certain parts of seam.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | seismic events, rockburst, focal mechanism, local principal stress |
| Subjects: | Methodology > Method and procesing > Source parameter estimation Methodology > Method and procesing > Technology-seismicity interaction Region > Poland > Upper Silesia Inducing technology > Underground mining |
| Project: | IS-EPOS project > USCB: Regional seismicity and ground motion associating underground coal mining EPOS-IP > USCB: Regional seismicity and ground motion associating underground coal mining IS-EPOS project > BOBREK MINE: Seismicity linked to longwall mining EPOS-IP > BOBREK MINE: Seismicity linked to longwall mining |