CC BY
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Lyudmila Yu. Sergeeva, Aleksei V. Berezin, Nikolai I. Gusev, Sergei G. Skublov, Aleksei E. Mel nik
Age and Metamorphic Conditions of the Granulites...
11 "
S
Ph
600
700
800
900
Temperature, °C
Fig.6. The stability field of mineral pangenesis in sample 174 (gray fill), calculated in the Theriak-Domino software package [8] for the MnNCMFATSH system at aH2O = 0.8. The regions of the minimum PT-parameters (~720 °C h 7 kbar) for the Grt + Opx + Pl + Amp association and the maximum PT-parameters (~775 °C h 7,5 kbar) for the Opx + Pl association are shown by ellipses (black fill and bold
dotted line, correspondingly). The boundaries of the amphibolite and granulite facies are shown by Oh and Liou [13]. The sidebar shows the convergence of the mineral reaction lines for the Grt + Opx + Pl + + Amp association, calculated in the TWQ program [7]
for estimating the rock's bulk composition with equilibrium mineral paragenesis is to calculate it by the actual minerals compositions ratios. The isopleths of garnet (Alm, Py, Grs) and plagioclase (An) end members, magnesia and Al content in orthopyroxene (apfu) were calculated and constructed by the actual method. Further, with a comparison of the calculated compositions and measured ones, was constructed a rather compact region (the black ellipse in Fig.6), showing the area, where minerals compositions are the closest. The obtained PT-parameters (720±10 °C. 7.0±0.2 kbar) are almost equal to the TWQ ones.
The evaluation of the early high-temperature metamorphism PT-parameters is a much more complex task since only the most basic plagioclase and orthopy-roxene with maximum alumina content can be assigned to the minerals, formed in this conditions. Using the principle of effective bulk composition [8] corresponding to the retrograde metamor-phism, garnet and amphibole were removed from the calculations. Then iso-
pleths for the anorthite component in plagioclase, and the tschermakite component and magnesia in orthopyroxene were calculated. Using the above-described method, a region corresponding to the maximum PT-parameters (dotted ellipse in Fig.6) with a temperature of 775±35 °C and a pressure of 7.5±0.7 kbar was constructed. This approximate estimate indicates that the protolith at an early stage experienced metamorphism under granulite-facies conditions. The additionally calculated area of coexistent real mineral paragenesis (gray fill in Fig.6) indicates the possibility of observed paragenesis formation in the extended in temperature, but limited in pressure interval.
Thus, the sequence of the rock metamorphic transformations can be traced: high-thermal granulite facies metamorphism (T<810 °C and subsequent sub-isobaric (about 7 kbar) cooling to 700 °C with the water activity increase and Grt-Amph paragenesis formation. corresponding to the granulite to amphibolite facies transitional phase [13].
Conclusions. The detailed study of plagio-crystalline schist from the Upper Anabar series provides new information on the age, geochemical features, and PT-conditions of the rocks formation. The plagio-crystalline schist protolith is the basic rock not containing primary magmatic zircon. The age of 1997±10 Ma, obtained by the U-Pb zircon dating corresponds to the time of granulite facies metamorphism. Sm-Nd age of 1919±13 Ma obtained from the whole rock, bulk garnet, and amphibole probes indicates the regressive amphibolite facies metamorphism. The granulite facies meta-morphism peak conditions are determined as 775±35 °C and 7.5±0.7 kbar. The regressive stage of metamorphism, which led to the Grt-Amph paragenesis formation, occurred at the temperature of about 700 °C and pressure of 7 kbar.
Acknowledgements. The authors are grateful to O.L.Galankina, E.S.Bogomolov (IPGG RAS), S.G.Simakin, E. V.Potapov (IPT RAS) and colleagues of the VSEGEI Institute for analytical studies. The study was carried out with the financial support of the Russian Foundation for Basic Research (grants 17-35-50002, 16-35-60092, 18-35-00229).
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REFERENCES
1. Avchenko O.V. Petrogenetic informative features of garnets from metamorphic rocks. M.: Nauka, 1982. 100 p (in Russian).
2. Geological Map of the USSR on a Scale 1:200000. Anabar Series. Sheets R-49-XIX, XX. Explanatory Notes. Ed. by A.A.Poturoev. Moscow, 1984. 82 p (in Russian).
3. Berezin A.V., Travin V.V., Marin Y.B., Skublov S.G., Bogomolov E.S. New U-Pb and Sm-Nd ages and PT estimates for eclogitization in the Fe-rich gabbro dyke in Gridino area (Belomorian Mobile Belt). Doklady Earth Sciences. 2012. Vol. 444. N 2, p. 760-765 (in Russian).
4. Sobolev A.V., Batanova V.G. Mantle lherzolites of the Troodos ophiolite complex, Cyprus - clinopyroxene geochemistry. Petrology. 1995. Vol. 3, N 5, p. 440-448 (in Russian).
5. Fedotova A.A., Bibikova E.V., Simakin S.G. Ion-microprobe zircon geochemistry as an indicator of mineral genesis during geochronological studies. Geochemistry International. 2008. Vol. 46. N 9, p. 912-927 (in Russian).
6. Anczkiewicz R., Thirlwall M.F. Improving precision of Sm-Nd garnet dating by H2SO4 leaching: a simple solution to the phosphate inclusion problem. Geochronology: Linking the isotopic record with petrology and textures. Journal of Geological Society London. Special Publications. 2003. Vol. 220, p. 83-91.
7. Berman R.G. Thermobarometry using multi-equilibrium calculations: a new technique, with petrological applications. Canadian Mineralogist. 1991. Vol. 29, p. 833-855.
8. De Capitani C., Petrakakis K. The computation of equilibrium assemblage diagrams with Theriak/Domino software. American Mineralogist. 2010. Vol. 95, p. 1006-1016.
9. Hinton R.W., Upton B.G.J. The chemistry of zircon: Variations within and between large crystals from syenite and alkali basalt xenoliths. Geochimica et Cosmochimica Acta. 1991. Vol. 55, p. 3287-3302.
10. Hoskin P.W.O. Trace-element composition of hydrothermal zircon and the alteration of Hadean zircon from the Jack Hills, Australia. Geochimica et Cosmochimica Acta. 2005. Vol. 69, p. 637-648.
11. Ludwig K.R. ISOPLOT/Ex - A geochronological toolkit for Microsoft Excel, Version 2.05. Berkeley Geochronology Center Special Publication. 1999. N 1a. 47 p.
12. McDonough W.F., Sun S.S. The composition of the Earth. Chemical Geology. 1995. Vol. 120, p. 223-253.
13. Oh C.W., Liou J.G. A petrogenetic grid for eclogite and related facies under high-pressure metamorphism. Island Arc. 1998. Vol. 7, p.36-51.
14. Grimes C.B., John B.E., Cheadle M.J., Mazdab F.K., Wooden J.L., Swapp S., Schwartz J.J. On the occurrence, trace element geochemistry, and crystallization history of zircon from in situ ocean lithosphere. Contributions to Mineralogy and Petrology. 2009. Vol. 158, p. 757-783.
15. Scherer E.E., Cameron K.L., Blichert-Toft J. Lu-Hf garnet geochronology: closure temperature relative to the Sm-Nd system and the effects of trace mineral inclusions. Geochimica et Cosmochimica Acta. 2000. Vol. 64, p. 3413-3432.
16. Watson E.B., Wark D.A., Thomas J. Crystallization thermometers for zircon and rutile. Contributions to Mineralogy and Petrology. 2006. Vol. 151, p. 413-433.
17. Wei C. Calculated phase relations in high-pressure metapelites in the system NKFMASH (Na2O-K2O-FeO-MgO-Al2O3-SiO2-H2O). Journal of Petrology. 2004. Vol. 45, p. 183-202.
18. Whitney D.L., Evans B.W. Abbreviations for names of rock-forming minerals. American Mineralogist. 2010. Vol. 95, p. 185-187.
Authors: Lyudmila Yu. Sergeeva, Leading Engineer, [email protected] (A.P. Karpinsky Russian Geological Research Institute, Saint-Petersburg, Russia), Aleksei V. Berezin, Candidate of Geological and Mineralogical Sciences, Research, [email protected] (Institute of Precambrian Geology and Geochronology RAS, Saint-Petersburg. Russia), Nikolai I. Gusev, Head of Eastern Siberia ores Department, [email protected] (A.P. Karpinsky Russian Geological Research Institute, Saint-Petersburg, Russia), Sergei G. Skublov, Doctor of Geological and Mineralogical Sciences, Professor, Chief Researcher, [email protected] (Institute of Precambrian Geology and Geochronology RAS, Saint-Petersburg. Russia), Aleksei E. Melnik, Candidate of Geological and Mineralogical Sciences, Junior Researcher, [email protected] (Institute of Precambrian Geology and Geochronology RAS, Saint-Petersburg. Russia).
The article was accepted for publication on 22 January, 2018.
^Evgenii T. Voronov, Vladimir N. Tyupin
Substantiation of Strength of the Filling Mass.
Mining
UDC 622.273.2 (031)
SUBSTANTIATION OF STRENGTH OF THE FILLING MASS BY TAKING
A BLAST EFFECT INTO ACCOUNT FOR THE ROOM-AND-PILLAR METHODS
Evgenii T. VORONOV1, Vladimir N. TYUPIN2
1 Transbaikal State University, Chita, Russia
2 Belgorod National Research University, Belgorod, Russia
The development of the uranium ore bodies at the ore mines of PJSC «Priargunsky Industrial Mining and Chemical Union» (PJSC «PIMCU») by room-and-pillar method as high as a pillar between the levels (60 m) without fill, as a rule, leads to the fall of the adjoining rock, to the strong contamination of the ore and to the high yield of the oversize pieces of the barren rock. A longstanding industrial and theoretical research shows that the sizes of the self-sustaining rock escarpments at the ore mines of PJSC «PIMCU» in the solid mass of trachydacites, conglomerates, sandstones, felsites are equal to 20-40 m. Moreover, the sizes of the self-sustaining rock escarpments depend to a great extent on the intensity of fracturing of the adjoining rocks. The stable size of the escarpment does not exceed 5-10 m for the rocks with the size of a jointing up to 0.05 m. Consequently, timely performance of the filling operations of the worked-out space of the chamber is important. However, the question then arises: which characteristic strength should the filling mass have?
The calculations of the characteristics of the filling mass in compliance with the reference guide «Shaft filling operations» show underestimated values of the characteristic compressive strength of the fill (1.4 MPa) for the room-and-pillar method, which leads to the increase of the ore contamination by the fill and provokes the additional costs for refilling of the volumes of the rock fall.
On the basis of the Russian experience of using of the consolidated fill for the development of the ore bodies of 15 m thickness by chamber method the strength of the fill is taken as 3-5 MPa under the resultant value of the static stresses without taking into account the character of the dynamic loading stresses induced by the sequence blasthole ring initiating in a chamber. Overestimating the characteristic strength of the filling mass results in the high consumption of the cementing materials. On the basis of the theoretical research the authors suggested the theoretical dependence of calculation of the characteristic strength of the filling material with respect to com-pressive stresses of the fill induced by the blasting operations.
The process of designing of the filling mass with the zones of diverse strength for the room-and-pillar extraction with the consolidated rock fill is proven to be economically reasonable. The bottom zone of the solid mass should have high strength (3-4 MPa), and the strength of the upper zone should be up to 2-2.5 MPa.
Key words: filling mass, room-and-pillar methods, characteristic strength, blast effect, calculation formula
How to cite this article: Voronov E.T., Tyupin V.N. Substantiation of Strength of the Filling Mass by Taking a Blast Effect into Account for the Room-and-pillar Methods. Zapiski Gornogo instituta. 2018. Vol. 229, p. 22-26. DOI: 10.25515/PMI.2018.1.22
Relevance and state of the study of the problem. A PJSC «PIMCU» is the largest and unique in Russia mining and chemical complex dealing with the extraction and processing of the uranium ores. This is an object of stable extraction of the uranium. The deposits of the Streltsovskoye orefield are characterized by the variety of the parameters of the ore bodies occurrence, the appearance of a wide range of unfavorable mining and geological factors such as faulting of the ore bodies and ore-bearing rocks, high content of radon in the ore deposits, increasing danger from rock bursts in the process of the development of the bottom levels of the deposits; besides, mining and geological conditions of the development often become more complex in the process of exploitation at uranium ore mines operating at a permanent basis; the above mentioned factors create opportunities for reduction of the performance indicators.
The basic technology which focused on the predominant use of the cost-intensive undercut-and-fill layer mining method with the consolidated fill may appear to be unprofitable in case of the development of low-grade and medium-grade ores.
The on-coming decreasing of the reserves of the uranium ore mines with high levels of iron predetermines the necessity of a possible transfer to more cost-effective and highly-productive chamber systems with the consolidated fill and mass-breaking of the ore by blasting during underground mining operations at PJSC «PIMCU» [1].
For the moment 77.5 % of the steep ore bodies have thickness up to 2.6 m and 20 % of the ore bodies have thickness up to 1.2 m at the ore mines of PJSC «Priargunsky Industrial Mining and Chemical Union» (PJSC «PIMCU»). When considering the undercut-and-fill layer mining of the ore bodies (the average content is equal to 0.12 %) by skips of 3.6 m width the contamination of the
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Journal of Mining Institute. 2018. Vol. 229. P. 22-26 • Mining
^Evgenii T. Voronov, Vladimir N. Tyupin
Substantiation of Strength of the Filling Mass.
ore sometimes leads to its transfer to the out of balance ores and the efficiency of the extraction becomes rather low. A room-and-pillar extraction of thin ore bodies allows to increase drastically the efficiency of the extraction and to reduce the primary and the secondary ore contamination in case of adequate choice and set the parameters of drilling and blasting operations as well as the strength parameters of the filling mass.
However, as the experience show, the development of the ore bodies by room-and-pillar method as high as a pillar between the levels (60 m) without fill, as a rule, leads to the fall of the adjoining rock, to the strong contamination of the ore and to the high yield of the oversize pieces of a barren rock. A longstanding industrial and theoretical research show that the sizes of self-sustaining rock escarpments at the ore mines of PJSC «PIMCU» in the solid masses of trachy-dacites, conglomerates, sandstones, felsites are equal to 20-40 m [6]. Moreover, the sizes of self-sustaining rock escarpments depend to a great extent on the intensity of fracturing of the adjoining rocks. For example, for the rocks with the size of a jointing up to 0.05 m the stable size of the escarpment does not exceed 5-10 m. Consequently, timely performance of the filling operations of the worked-out part of a chamber is important. However, the question then arises: which characteristic strength should the filling mass have?
Depending on the conditions, the static forces (gravity and tectonic) and the dynamic stresses (induced by the blasting operations) are applied to the existing static field stress of the filling mass [2]. The artificial filling mass may be under compression, tensile, shear, bending stress and strain and "work" under conditions of uniaxial, two-dimensional and three-dimensional state of stress. To determine and control the characteristic strength of the filling mass on the production site it may be transformed into the tensile strength in uniaxial compression irrespective of the stress-strain behavior of the artificial filling mass.
The qualitative value of the stresses and strains in the filing mass is determined by the value of convergence of the walls of the worked-out area under the conditions of elasto-plastic deformation of the rocks in the destressed zone owing to gravity, tectonic forces [4], stresses induced by the blasting waves and the reaction of the filing mass [4].
In accordance with the generalized theoretical and practical data from the reference guide «Shaft filling operations» [2] in the process of the undermining of the artificial rock body by chambers of the underlying sublevel, the characteristic compressive strength of the fill is determined by Ferre formula:
* z=2.5V fL)3, (i)
where ct fnsie - a characteristic tensile strength of the fill, MPa.
The tensile stresses (in megapascals) at the contour of the horizontal baring of the artificial rock body for the room-and-pillar method are calculated by the modified formula [2]
°eL = 10-5 p fhequiv (0.95 - e"012a) KKr1, (2)
where pf - a volume weight of the fill, kg/m3; hequiv - an equivalent height of the load layer, m; a - a span of the baring of a chamber; Ki - a factor of ignorance equal to 1.5; Kl - a factor of the longtime strength taking the duration of baring into account.
In case of a short duration of baring of the fill (up to 1 year) Kl = 1, in case of a long duration of baring of the fill Kl = 0.5-0.7.
The formula (2) may be used if a < 0.85hf, where hf - a height of a filling mass. The equivalent height of the load layer with respect to the layer of superimposed load of bro-ken-up rock of Hequiv height is [2]
h =p rH equiv +p fhf equiv 5 W)
P f
where pr - a volume weight of the disintegrated rock, kg/m3.
^Evgenii T. Voronov, Vladimir N. Tyupin
Substantiation of Strength of the Filling Mass.
Characteristic strength of the fill in case of undermining of the artificial rock body for chamber methods
Span of undermining, Characteristic strength, MPa
m Tensile Compressive
5 0.7 1.5
10 1.0 2.5
15 1.17 3.2
20 1.26 3.5
25 1.35 3.9
Let the characteristic strength be defined for the case of the room-and-chamber method of the extraction of the thin ore bodies. The numerical values of the parameters: a = 3.5 m, Ki = 1.5,
pf = 1.8403 kg/m3, Ki = 0.7, pr = 1.75-103 kg/m3,
hf = 60 m, Hequiv = 0 (there is no layer of disintegrated rock above the block). Then according to the formula (3) hequiv = 60 m.
If we plug the numerical values in the formula (2) and then in the formula (1) we obtain an
adequate tensile strength of the fill aflnsiie = 07 MPa; according to the formula (1) the characteristic
compressive strength of the fill a Char = 14 MPa.
The calculations of the characteristic compressive strength of the fill according to the formulas (1)-(3) in case of a room-and-pillar method proved the compliance with the basic research and practice data from the reference guide [2] in which the strength characteristics depending on the span of a chamber are reported (see table).
However, Russian and foreign experience of applying a room-and-pillar method for the extraction and specifically the extraction of the uranium ore mines [5, 9] shows that the compressive strength of the fill should be taken not less than 3-5 MPa if the thickness of the ore body is up to 10 m. According to the paper [3] the compressive strength of the filling material is taken as 7-8 MPa for the filling material of the mined-out space. Such values may probably be explained by the fact that the blast-induced vibrations and the dynamic impact of a blast are not considered in the calculations (formulas 1-3).
Overestimating the strength of the filling mass results in a high consumption of the cementing materials. Underestimating the strength of the artificial filling mass increases the contamination of the ore by the fill and provokes the additional costs for refilling of the volumes of the rock fall.
An adequate characteristic compressive strength of the filling material must take into account not only static load determined by the formulas (1)-(3) but also dynamic load induced by periodic action of the blasting operations.
The analytic analysis of the dynamic effect of the blasting operations on the filling mass. According to the analysis of the numeric calculations the characteristic strength of the fill for the room-and-pillar method is determined by the gravity and the tectonic component of stresses (the static component) and also by the effect of the blasting operations (the dynamic component).
According to technical literature [2] the numerical calculations of the static component for the conditions of the ore mines at PJSC «PIMCU» the ultimate compressive strength is equal to 1.4 MPa which is several times less than the actual strength of the fill at the uranium ore mines (3-5 MPa) [5].
The compressive strength of the fill may be determined by the following formula
C
[a comp ] = a
char dyn. comp '
(4)
where a fL
A drawing to determine compressive stresses in a filling mass during blasthole
ring initiating 1 - a sublevel drift; 2 - blastholes; 3 - filling mass
24
- a static component, a characteristic compressive strength of the fill [see formula (1)]; adyn.comp - a dynamic component, a value of compressive stress induced by the sequence short-delay blasthole ring initiating.
^Evgenii T. Voronov, Vladimir N. Tyupin
Substantiation of Strength of the Filling Mass.
According to research [7] the deformation waves from the blasthole ring initiating (see figure) are refracted at the point C and propagate along the most stressed area of the rock mass (with the minimum of losses) and after that the waves induce the compressive stresses in the fill at the point D.
The value of compressive stresses at the distance from a short-delay blasthole ring which affect the filling mass [7; 8],
*Jn Dphdfc ( pv
rO I i- v A i- v
° d„ =— I 1 -^r: II 7^7 I K]K()K,(n)K1 (N), (5)
where r - a distance from the center (lengthwise) of the boreholes (point C) to the point D; ph, df, c, p, v - detonation characteristics and physico-engineering properties of rocks; O - characteristic of deformability of a jointed rock mass; K jK]](l)K]}(n)K± (N) - factors of the proportion of the
blast energy which is induced into the enclosing rock mass, the length of the blastholes, the number of the blastholes in a ring, the number of short-delay blasthole rings relatively,
f V5
k =(■ ) ; (6)
KM) = ln2,7
lf (l f - 2p d
f -1
d
(7)
le V e
Ky (n) = ln 2,7[n - 2p(n -1)]; (8)
KL (N) = ln(1,7 N +1). (9)
A factor which depends on a number of the blastholes in a ring introduces a width of a chamber implicitly. A factor depending on a number of the blasthole rings introduces a length of a chamber implicitly.
The numerical values of the parameters in the formulas (5)-(9) for the conditions of the ore mines at PJSC «PIMCU» considering the solid masses of trachydacites: a depth of 500 m, a span of undermining is equal to 3.5 m, a diameter of the blastholes of 57 mm, explosive granulite A6 is used, a length of a charge is equal to 8 m, a distance r = 5 m. The rest of the parameters: D = 3.3-103 m/s; ph = 1.1-103 Kr/m3; df = 0.057 m; c = 4.35-103 m/s; p = 0.45; v = 0.29; E = 4.75-1010 Pa; O = 8; n = 3; N= 5; de = 0,4 m; lf = 8 m; aa = 3.5 m; W = 1.5 m.
As a result, using the formulas (6)-(9) we obtain Kj = 0.5; Ky(/) = 2.05; Ky(n) = 1.17;
K±(N) = 1.8.
Substituting the numerical values into expression (5) we obtain the value of the dynamic stresses at the bottom zone of the filling mass (see figure). According to the numerical calculations the value of odyn.compr is equal to 1.8 MPa in the very bottom zone of the filling mass at the distance of 5 m from the center lengthwise the blastoles.
In this case, according to the formula (1) the characteristic compressive strength of the bottom zone of the filling mass is [acompr] = 3.2 MPa considering the calculated value equal to ° Tar = 14 MPa. There is a correspondence with the practical data obtained during the development
of the uranium ore bodies by the room-and-pillar method [5].
However, the increasing of a distance from the center of blasting charges to the fill encourages considerably the decrease of the value of odyn.compr. The calculated values of odyn.compr and the characteristic strength of the fill depending on the distance from the central part of the blasthole rings (r) are the following:
A distance from the center of charges to the fill, m ........... 5 8 12 15
A value of compressive stresses induced by blasting, MPa......1.8 1.1 0.7 0.6
A characteristic strength of the fill, MPa.................... 3.2 2.5 2.1 2.0
^Evgenii T. Voronov, Vladimir N. Tyupin
Substantiation of Strength of the Filling Mass.
Therefore, the filling mass may have zones of diverse strength: the bottom zone must have a higher strength equal to 3.0-4.0 MPa, the rest of the upper zone must have the strength up to 2.0-2.5 MPa.
Conclusions
On the basis of theoretical and experimental research as well as the analysis of the existing numerical methods of calculations of the characteristic strength of the filling material for the room-and-pillar extraction of the thin ore bodies the conclusions may be the following:
1. The calculations of the characteristics of the filling mass in compliance with the reference guide «Shaft filling operations» [2] do not take into account the dynamic stresses induced by sequence blasthole ring initiating in a chamber and show the underestimated values of the characteristic compressive strength of the fill (1.4 MPa) for the room-and-pillar method, which leads to the increase of the ore contamination by the fill and provokes the additional costs for refilling of the volumes of the rock fall.
2. From the perspective of the Russian experience of the use of the consolidated fill for the development of the ore bodies of 10 m thickness by chambers the actual strength of the fill is taken as 3-5 MPa.
3. On the basis of theoretical studies a new theoretical dependence of the calculation of the characteristic strength of the filling material was set by the authors; this dependence includes the compressive stresses of the fill induced by the blasting operations.
4. The process of designing of a filling mass with the zones of diverse strength is proven to be economically reasonable during room-and-pillar excavation with the consolidated fill. The bottom zone of the filling mass must have a higher strength (3-4 MPa), the upper zone must have the strength up to 2-2.5 MPa.
REFERENCES
1. Voronov E.T., Shurygin S.V. The prospects of the development of the underground geotechnologies for the development of the uranium deposits with respect to the factor of radiation. Vestnik Zabaikal'skogo gosudarstvennogo universiteta. Chita, 2014. N 3, p.3-9 (in Russian).
2. Shaft filling operations. Ed. by D.M.Bronnikova, M.N.Tsygalova. Moscow: Nedra, 1980, p.400 (in Russian).
3. Mosinets V.N., Abramov O.K., Mel'nichenko V.M. Zero-waste technology of the extraction of the radioactive ores. Ed. by V.N.Mosintsa. Moscow: Energoatomizdat, 1987, p.240 (in Russian).
4. Sinkevich N.I. The assessment of the natural state of stress of the rock mass at the Abakanskoye deposit. Gornyi zhurnal. 2003. N 11, p. 30-31 (in Russian).
5. Sleptsov M.N., Azimov R.T., Mosinets V.N. The underground mining of the nonferrous and rare metals. Moscow: Nedra, 1986, p.206 (in Russian).
6. Tyupin V.N. The setting of dynamically stable dimensions of escarpments of the stressed jointed rock mass during chamber systems of development. Vestnik Zabaikal'skogo gosudarstvennogo universiteta. Chita, 2016. Vol. 22. N 6, p. 31-39 (in Russian).
7. Tyupin V.N., Mikhailovskii A.V. Blast action in a stressed jointed rock mass during mine working and railway tunneling. Vestnik Chitinskogo gosudarstvennogo universiteta. 2009. N 6 (57), p.74-78 (in Russian).
8. Tyupin V.N. A blast influence on the stressed state of the rock mass and lining during construction of the railway tunnels. Sovremennye tekhnologii. Sistemnyi analiz. Modelirovanie / IrGUPS. 2011. N 3 (31), p. 87-90 (in Russian).
9. Khomyakov V.I. A foreign experience of fill use at the ore mines. Moscow: Nedra, 1984, p. 187 (in Russian).
Authors: Evgenii T. Voronov, Doctor of Engineering Sciences, Professor, [email protected] (Transbaikal State University, Chita, Russia); Vladimir N. Tyupin, Doctor of Engineering Sciences, Professor, [email protected] (Belgorod National Research University, Belgorod, Russia).
The paper was accepted for publication on 28 April, 2017
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Journal of Mining Institute. 2018. Vol. 229. P. 22-26 • Mining
