Marcak, Henryk (2011) The seismic activity due to the bending on exploited seam roof. In: 22nd World Mining Congress & Expo, 11-16 SEPTEMBER 2011, Istanbul.
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Marcak_2011_THE SEISMIC ACTIVITY DUE TO THE BENDING OG EXPLOITED SEAM ROOF.pdf - Published Version Download (1MB) | Preview |
Abstract
Risk estimation of strong mining tremors in underground mines, only from seismological observations, is not satisfactory. In Poland a strong sedimentary layers appear over exploited seams and most of seismic events is located in roof layers. It seems to be important for seismic activity a bending roof layer into old workers. The plastic deformations and yield fracturing in result of bending are treated in this paper as the main source of seismic events. Dynamic temporal evolution of the rupturing process is related to the event distribution. The elastic stresses have compressed character in the layer underside, while at its overside layer is stretched. Dislocation creep in the external parts of layer may accelerate the fracture deformation. The plane of failure is formed and the seismic events are related to this surface. The seismic data presented in the paper, has been recorded and collected in the copper mines in Poland. When the fracture is developing in overside of the layer the energy of events related to this fracture is limited. The penetration of fracture up over layer border or more dangerously down into underside of layer intensively enlarge rupture surface and increases the energy of seismic events related to it. The changes of seismic surface area can be recognized from analyze of the hypocenter position and mining observations.
| Item Type: | Conference or Workshop Item (Paper) |
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| Subjects: | Region > Poland > Legnica-Glogow Copper District Inducing technology > Underground mining Methodology > Method and procesing |
| Project: | IS-EPOS project > LGCD: Regional seismicity and ground motion associating underground hard rock mining |