Calculation of the Stress State of the Coal-bearing Massif Containing In-seam Workings and Tectonic Violation


N.V. Cherdantsev, Dr. Sci. (Eng.), Chief Research Associate, nvch2014@yandex.ru FITs UUKh SO RAN, Kemerovo, Russia

Annotation:

The model of geomechanical state of the coal-bearing massif containing mine workings done near the tectonic violation in the form of the narrow slit filled with an elastic material with the specified stiffness characteristics for compression and displacement is presented in the article. The model is built on the basis of the main positions of the mechanics of the deformable solid body with the use of the boundary element method and assumes that the massif is in the flat deformed state and is loaded with an equi-component stress field. At the same time, it is considered that the characteristics of the seam strength are lower than those of the host rock massif, but higher than the strength characteristics on their contact. The characteristics of the conventional seam stresses are represented by the Prandtl diagram with a horizontal section of the limiting deformation. The epures of the bearing pressure were built in the marginal part of the bed in the presence of the tectonic violation in the massif in the form of: the rock layer with low strength characteristics (the first type), discontinuous (disjunctive) violation (the second type). The violation intersects the workings at an angle of 30° to the horizon and passes through the center of gravity of its cross section. It is shown that disjunctive fault has the most significant effect on the parameters of the bearing pressure in the marginal part of the bed, increasing their values in comparison with the massif, in which there is no violation. In this case, the effect of unloading some elastic part of the bed occurs leading to decrease in vertical stresses as compared to the stresses in the undisturbed massif.

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DOI: 10.24000/0409-2961-2018-6-7-12
Year: 2018
Issue num: June
Keywords : coal-bearing massif in-seam workings extremely-intense state narrow slit tectonic violation boundary element method
Authors:
  • Cherdantsev N.V.
    Cherdantsev N.V.
    Dr. Sci. (Eng.), Chief Research Associate, nvch2014@yandex.ru Federal Research Centre of Coal and Coal Chemistry of SO RAN, Kemerovo, Russia