Mykola Stadnichuk1, Oleksandr Krukovskyi2, Serhii Kurnosov3, Serhii Makeiev4
1Department of Mine Energy Complexes, M.S. Polyakov Institute of Geotechnical Mechanics NAS of Ukraine, Dnipro, Ukraine, E-mail: krosh1983@gmail.com
2Department of Rock Mechanics, M.S. Polyakov Institute of Geotechnical Mechanics NAS of Ukraine, Dnipro, Ukraine, E-mail: igtm@ukr.net
3Department of Mineral Mining at Great Depths, M.S. Polyakov Institute of Geotechnical Mechanics NAS of Ukraine, Dnipro, Ukraine, E-mail: sakurnosov@gmail.com
4Department of Mineral Mining at Great Depths, M.S. Polyakov Institute of Geotechnical Mechanics NAS of Ukraine, Dnipro, Ukraine, E-mail: smakeev@ukr.net
Corresponding author: Serhii Makeiev, E-mail: smakeev@ukr.net
ABSTRACT. The current paper is devoted to experimental tests of working protection means in the construction of which concrete in liquid state is used. Such means of protection are most vulnerable to irreversible deformations during the period of their hardening, which coincides with the period of intensive growth of pressure on them from the side of the rock massif. Studies have shown that the pressure of fake rocks on the working protection means depends significantly on the depth of its location and the category of collapse of the roof of the coal seam. The maximum pressure is reached at the moment before the collapse of the roof, that is, at the maximum values of the length of the console of fake rocks, which hangs over the produced longwall space and rests on the working protection means. It was established that the pressure of the fake roof of the coal seam and the relative vertical deformation of the district roadway protection means increase according to the logarithmic dependence of the distance to the longwall outcrop and the time of concrete hardening. With heavy and medium roof collapse, these processes are divided into two stages: in the first stage (the length of which corresponds to the step of the roof collapse), as the longwall moves, the pressure increases intensively, at the moment of collapse it drops by 15-20%, and in the second stage again increases, but 6-8 times more slowly than in the first one, and, provided the relative vertical deformation of the protective device stabilises, passes into a stable mode. With an easily collapsed roof, the step of its collapse does not have a significant effect on the growth and stabilisation of the stress-deformed state of the protective device. The mechanism was revealed and the regularities of loading and deformation of district roadway protection means from a quick-setting mixture depending on the time of its hardening and the distance to the outcrop of longwall, taking into account the category of stability of the roof of the coal seam, were established. Implementation of recommendations for the parameters and technology of the construction of a guard-isolation wall in the conditions of the “Chervonogradska” and “Lisova” mines of the SE “Lvivvugilya” made it possible to reduce the costs of cement-mineral mixture by 27% and save the belt roadways No. 562 and No. 166 for reuse in the production as ventilation during the working out of the adjacent trench column.
Key words: means of protection of district roadways, quick-setting mixtures, concrete packaged protection wall, load intensity of protection means.
DOI: https://doi.org/10.58903/u17190833
EXPERIMENTAL TESTS OF CONCRETE MEANS OF PROTECTION FOR COAL MINES DISTRICT ROADWAYS
References
Bulat, A. F., Iljashov M. A. & Usachenko B. M. (ed.), (2004). Temporary Technological Regulations for the Protection of Development Workings of Coal Mines with Cast Strips of Hardening Materials, RIA Dnepr-VAL, Dnepropetrovsk, Ukraine.
Bulat A. .F. (2014). Advanced Technologies for Tunnel Supporting in Ukrainian Coal Mines, Visnyk of the National Academy of Sciences of Ukraine, 1, 74-79, https://doi.org/10.15407/visn2014.01.074.
Bulat A. F., Smirnov A. V., Kurnosov S. А., Vozijanov V. S., Tsikra A. A., Zaderiy V. V. & Averkin D.I.(2014). The Method of Working Protection, UA Patent 92305, Patented on 11 August 2014.
КD 12.01.01.503, (2001). Roof Control and Fastening in Longwalls on Coal Seams with Dip Angle up to 350, Kyiv, Ukraine.
Nekache, R., Boukelloul M. & Fredj M. (2015). Stability Analysis of Underground Mining and their Application on the Mine Chaabte El Hamra, Algeria. Procedia Earth and Planetary Science, 15, 237-243, https://doi.org/ 10.1016/j.proeps.2015.08.058.
NPAOP 10.0-7.08-93, (1996). Coal Mine Ventilation Design Guide, Kyiv, Ukraine.
NPAOP 10.0-1.01-10, (2010). Safety Rules in Coal Mines, Kyiv, Ukraine.
Rotkegel, M & Bock S. (2015). Impact of Plates Dimensions on Interaction of Mine Workings Support and Rock Mass, Journal of Sustainable Mining, 14 (1), 12-20, http://doi.org/10.1016/j.jsm.2015.08.003.
Stadnychuk, M. M., Kurnosov S. A., Makeiev, S.Y. Justification of the conformity of the quick-setting mmixture parameters to the conditions of using safety means for the district workings, Szkoła Eksploatacji Podziemnej 2023: Materiały Konferencyjne, Kraków, 27.02–1.03.2023, Kraków: Instytut Gospodarki Surowcami Mineralnymi i Energią Polskiej Akademii Nauk, (pp. 632-636). https://szkolaeksploatacji.pl/wp-content/uploads/2023/02/materialy_sep_2023.pdf.
Xing, Y., Kulatilake, P. & Sandbak, L. (2019). Rock Mass Stability Around Underground Excavations in a Mine. CRC Press, London, UK, https://doi.org/10.1201/ 9780429343230.
Zhang, Z., Shimada, H., Sasaoka, T. & Hamanaka A. (2017). Stability control of retained goaf-side gateroad under different eoof conditions in deep underground Y type longwall mining, Sustainability, 9(10), 1671, https://doi.org/10.3390/su9101671.
Zhao J-J, Zhang Y. (2017). Studies on rock failure of layered rocking underground mining-face and control techniques. Geomech Geophys Geo-Energy Geo-Resour, 3, 405-414, https://doi.org/10.1007/s40948-017-0068-0.