Investigation of subsidence process angular parameters during secondary underworking in the conditions of Western Donbas
О. Masyk1, О. Kuchin1, О. Belichenko1
1 Dnipro University of Technology, Dnipro, Ukraine
Coll.res.pap.nat.min.univ. 2020, 61:27-36
https://doi.org/10.33271/crpnmu/61.027
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ABSTRACT
Purpose. Investigation of high-thickened sediments influence on the angles of draw during secondary underworking.
The methodology consists in the analysis and mathematical processing of the results of mine surveying instrumental observations of the Earth's surface subsidence in various mining and geological underworkingconditions. The paper generalizes the results of experimental data analysis during primary and secondary underworking.
Findings. The paper investigates the values of the angles of draw obtained from the data of instrumental measurements at observation stations in the Western Donbas. The dependence of their values in different sections of subsidence profile is analyzed, and at this basis it is established that the values of the angles of draw in sections above set-up entry and above gateroads are different. On the basis of comparison of angular parameters obtained by experimental studies and their predicted values the significant difference is established. It is determined that the separate usage of angular parameters in sediments and bed rock with current values of draw angles is not reasonable for the Western Donbas conditions. Using the current standard predicting values of angles of draw in sediments, their values in bed rock exceeds 90°, which is contrary to the existing ideas of the subsidence process.
The originality. It is established for the first time that the value of the angle of draw depends on the direction of a longwall advance under the conditions of secondary underworking The new values of draw angles for the underworking of Western Donbas strata are obtained – this allows for more accurate determination of the influence area boundaries of the Earth's surface and increase in the accuracy of subsidence prediction.
Practicalimplications. The research results allow for adjustment of the angles of draw determination method for the conditions of secondary underworking in the Western Donbas, and of the Earth's surface subsidence prediction.
Keywords: angles of draw, maximum values, sediments, bed rock, subsidence profile, the Earth's surface, Western Donbas.
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