ArticleName |
Stress state estimation in coal bed under random conditions in contact zone with enclosing rocks based on inverse problem solution |
ArticleAuthorData |
Institute of Integrated Mineral Development – IPKON, Russian Academy of Sciences, Moscow, Russia:
A. L. Karchevsky, Leading Researcher, Doctor of Physico-Mathematical Sciences L. A. Nazarova, Leading Researcher, Doctor of Physico-Mathematical Sciences, lanazarova@ngs.ru V. N. Zakharov, Director, Corresponding Member of the Russian Academy of Sciences L. A. Nazarov, Leading Researcher, Doctor of Physico-Mathematical Sciences |
Abstract |
Seismic monitoring is an integral element of a hard mineral mining technology. The seismic data interpretation is possible with various approaches (statistical, deterministic, integrated) and is aimed to obtain information on geomechanical conditions of rocks. This article suggests the method to recover stress field in coal and rock mass based on inverse problem solution. Within a two-dimensional linearly elastic model of coal bed deformation under mining, the authors formulate and prove resolvability of an inverse problem on the conditions in horizontal contact zones based on the data on distribution of normal octahedral stress s(х): • using acoustic probing or tomography, the velocity V(x) is determined in the middle section of a coal bed; • based on the lab test data on rocks in the bed under mining, the empirical relation V = F(s) is obtained. Using the results, the input data s(х) = F^{–1}(V(x)) are calculated for the inverse problem to determine the boundary conditions and, thus, to recover the stress–strain state in the coal bed. The mechanism of initiation and development of an outburst has been proposed and theoretically validated: the presence of areas with low cohesion in the contact zones between coal bed and enclosing rock mass conditions formation and expansion of horizontal tensile stress zones at the coal bed edges in the course of heading, which induces the risk of splitting-off of coal due to its low tensile strength. The study has been supported by the Russian Science Foundation, Project No. 16-17-00029. |
References |
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