Rock mass deformation modeling using the non-Archimedean analysis

The non-Archimedean space is a multi-scale one. The paper shows that this face is applicable to developing mathematical models of rocks exhibiting a hierarchy of structural levels. A closed model, considering anisotropy and weakening of a rock mass, is constructed. The equations in terms of displacements and the resultant internal force vector are derived. The authors have obtained the numerical solution to the problem on deformation of a rock mass around extended galleries, and showed how the areas of weakening and residual strength evolve. The energy flow lines are plotted. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 1, pp. 3–16, January–February, 2008.     

Turboblasting explosive charges. III: Profile of the detonation reaction path

The detonation of individual solid explosives of C_aH_bO_cN_d type is described by introducing the concept of a nonthermal potential as the sum of several types of energy—chemical energy, elastic compression, the electron state of the molecules, and the kinetic energy of the flux. Graphs of the variation in the nonthermal potential and the internal energy of the substance, the kinetic energy of the flux, and the pressure in the head region of the detonation wave right up to the Chapman-Jouguet plane are plotted. The relations between the various types of works performed at the shock front are calculated. Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk. Translated from Fiziko-Tekhnichskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 60–71, March–April, 1999.     

Test stand for pneumatic hammers

The impact energy damping stand is designed to test pneumatic hammers. The choice of material to be a damping material is reasoned. Deformation is established for the damping material under an impact impulse effect. The calculation method is proposed to evaluate the basic damper parameters for the stand. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 58–65, November–December, 2007.     

Undulant rock pressure distribution along a longwall face

The paper presents measurement data on pressures in legs of a powered support in a longwall. The authors show that the rock pressure distribution along the longwall face is undulating and, based on the geomechanical calculation, find the relationship between the energy density of the rock mass and support. Based on the case study of a longwall before a rockburst, it is shown that the seam energy density decrease can initiate the rockburst. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 38–45, March–April, 2009.     

Identification of stresses in rocks on the basis of changes in density of infrared radiation flux

The efficiency of infrared radiometry as a source of information on changes in the stress state of rocks is substantiated experimentally. The experiments were conducted under conditions of pulse actions. An analysis of synchronized records of the mechanical state of the specimen and the corresponding variations in the intensity of heat flux from its surface shows the reliability of recording and evaluating “jumps” in stresses on the basis of radiometric data. The Gersevanov Scientific-Research Institute of Foundations and Underground Structures, Moscow. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 48–53, November–December, 1999.     

Energy analysis of open-pit coal mining

Conclusions 1. The use of energy criteria to establish the mine boundaries corresponds to the role of coal-mining enterprises as subsystems within the energy-production system. The criteria here proposed reflect the level of technology not only within coal mining but also within the power industry and in transportation. It is important that the parameters included in the criteria have a physical basis reflecting the energy needs of the technologies employed and hence may be more reliably measured than can economic parameters. However, this is not an adequate basis for the absolute adoption of an energy approach rather than an economic approach. 2. The criteria proposed for determining the mine boundaries are based on the energy parameters both of the technologies employed and of the coal deposit, which allows the geological and other mine conditions, the processes of coal extraction and enrichment, and also transportation and energy production to be combined within a single system. This permits more reliable prediction of the determining factors, since they are based on physical parameters, which is not true of economic factors. The importance of this is evident in that, with rare exceptions, the mine boundaries may be established in the long term: 20–50 years or more. 3. There is one disadvantage in using energy analysis to solve problems associated with coal extraction: it is not traditional (although this approach — known as the exergetic approach — is widely used in other fields). However, since it is of growing importance to make rational use of nonrenewable energy resources, this disadvantage may be turned into an advantage. Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 5, pp. 78–89, September–October, 1997.     

Flow of a friable medium with possible unlimited slip over the localization surfaces

Conclusions 1. In the general case, steady loading conditions of a friable medium result in a deformation process that is either steady or near-periodic. 2. The pattern of localization lines depends on the contour of the deformed region. At small compression, the lines resemble logarithmic spirals. With increase in compression, they become closed and resemble Cassinian ovals. Families of Cassinian ovals are encountered in the most diverse branches of mechanics and physics (in phase portraits of different physical pictures, patterns of equipotential and electrostatic lines, etc.). In the present work, this family, in all its diversity, including Bernoulli lemniscates, is obtained in experiments with friable material. This agreement cannot be random and evidently indicates the appearance of some general law. 3. Steady slip lines, at which slip continues for as long as is desired, are obtained. This result may be used to investigate the properties of various geological materials in conditions of unlimited shear. Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 37–42, May–June, 1997. The present work was supported by the Russian Fund for Fundamental Research (Grant No. 94-05-16428).     

Experimental simulation of spiral slip lines on granular materials

The experimental results of modeling geomedium around a mine working are reported. Two families of spiral slip lines are reproduced on a granular material. One or two families of log spiral slip lines arise around a cylindrical foreign body simulating a supported mine working. It is shown that shears on the lines of different families develop irregularly. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 3–9, March–April, 2009.     

Impact loading of a hard rock via plastic substance in a drill hole

Using experimental data as the base, the calculation scheme is developed for estimating the impact energy required for crack generation as against sizes of a drill hole, parameters of a tool, and properties of a rock and a plastic substance applied. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 79–86, November–December, 2006.     

Concept of a rock-breaking working element of an underground kimberlite ore mining machine

The paper presents a review of the roadheaders’ working element designs suitable to be equipped with shearing disks capable of kimberlite ore disintegration with admissible energy consumption and considerably reduced wear of a working element. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 98–105, November–December, 2006.     

Study of cryogenic disintegration of gold-quartz ores to intensify the heap leaching of gold

It is shown how the airy and nival conditions of cryogenic eolation affect the structural changes and weakening of gold-qnartz sulfide ores under cyclic exposure to frost-penetration and thaw. It is revealed that leaching of ores after cryogenic eolation in the nival conditions and additional pretreatment is more intensive, by 25%, than leaching of ores that were not prepared by cryogenic eolation. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 1, pp. 102–110, January–February, 2006.     

Increase in efficiency of the trenchless underground construction methods by using the compressed air transfer

The possibility to increase the trenchless service lines laying efficiency by removing continuously broken rock by an air flow is considered. The procedure is proposed for calculating the main parameters of the compressed air transfer. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 5, pp. 52–61, September–October, 2007.     

Wave spectra in oscillatory systems

Conclusions Analysis of dynamic models of the block structure of rock and oscillatory systems in aeroelastic conditions indicates that, in the presence of no less than two degrees of freedom, they are all characterized by the applicability of a soliton-like oscillatory model. In investigating an oscillatory model of the support at the side of a mine working in the form of a freely suspended plate, the presence of a line spectrum of oscillations with a soliton-like pendulum transfer of the energy between spectral modes over time is established. The interaction of the oscillating plate with air at the resonant frequency of the elastic waves sharply localizes the oscillatory energy in soliton-like pendulum conditions. The existence of a piston mechanism for the plate's interaction with the air is confirmed. The range of existence of canonical coordination of frequencies in the spectra of oscillatory systems is extended from block structures to the aeroelastic region, with the same modulus {ie208-1}, i=0, ±1, ±2, …. Financial support for this work was provided by the Russian Fund for Fundamental Research (project 96-05-66052). Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 18–27, May–June, 1998.     

Predicting the burst hazard of coal seams from physical indices

Conclusions A method is proposed for predicting bursts in coal seams by means of an index which for the first time takes comprehensive account of the seam stress and the energy of the gas which can take part in the burst, these values being determined in the light of the physical and mechanical properties of the coals themselves. The author shows how it is possible to determine quantitatively the burst probabilities for various mining and geological conditions. Skochinskii Mining Institute, Moscow. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 23–26, March–April, 1968.     

Electric-discharge cutting of rocks

The test data are reported on rock cutting by the electric discharge with movable and stationary electrodes. The specific crushing energy is determined, the electrode system design is optimized, and the high-voltage impulse parameters selected for highly efficient fracture. The study results make the grounds to develop an electric-discharge cutter for rocks and concrete. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 70–77, March-April, 2008.     

Promising Pneumatic Punchers for Borehole Drilling

The state of borehole drilling by downhole pneumatic punchers and their potential use in open and underground mining as well as in exploration for reliable samplign are analyzed. Performance specification is presented for the new-generation pneumatic punchers equipped with a pin tool, effectively operating at a compressed-air pressure of 0.5...0.7 MPa, and with an additional extended exhaust from the power stroke chamber during working cycle. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 74–78, March–April, 2005.     

Combined hole-making in soil by impact devices with an annular working organ

The physical scaled model is developed, the air-distribution system of the impact drive of the model is equipped with an elastic valve in the air supply system, and the drive provides step-by-step control of the impact pulse frequency under conditions of a single impact with a constant energy. The experimental relationships are established for the variations of the soil drifter movement velocity in the course of the tunnel advance within the studied range of the operating frequency of its impact drive and the feeding of a power traction organ. The relations between consolidated and excavated soil portions are determined for different technological modes of the tunnel advance. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 87–97, November–December, 2006.     

Substantiation of the sequence for opencast mining of a series of flat and inclined strata using the mined-out space for internal dumps

The possibilities of using the mined-out space of opencasts for placing the overburden in internal dumps are studied. It is established that on completion of mining flat and inclined strata there are free capacities in the mined-out space consisting of 40–70% of its volume which are a resource for placing the overburden from other opencasts with substantiation of the sequence of mining large deposits. A complex criterion is suggested that takes account of energy expenditures for mining a deposit and the energy damage caused to the environment. A procedure is given for solving the problem and results are presented of calculations for the Taldinsk and the Tomusinsk deposits. Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 97–106, May–June, 1999.     

Experimental simulation of rockslide fragmentation

The paper describes the structural features of rockslides and draws a comparison between the energy efficiencies of fragmentation by a rockslide, breakage by blasting and destruction in a crusher. The authors have reproduced in the laboratory conditions the mechanism of heavy fragmentation of strong rocks under static loads typical of the real rockslides and with retained initial structure of the rock mass. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 13–20, March–April, 2008.     

Low-frequency resonances of seismic luminescence of rocks in a low-energy vibration-seismic field

Results are presented for an investigation of the effect of monochromatic low-frequency vibrations generated by surface sources on the seismic emission of oil-producing strata under in-situ conditions. The resonance nature of seismic luminescence of rocks is detected. The connection of the observed resonance pattern with the block-hierarchical structure of the medium is demonstrated. Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 1, pp. 3–7, January–February, 1999.