Regularities of interaction between seismic waves and long structural faults

Based on the studied features of propagation of seismic waves in a rock mass with a long structural fault, the authors have found the relationships between the seismic wave attenuation and weakening by the fault, the physic-mechanical properties of the fault filler, the fault thickness and the wave incidence angle. It is shown that relative displacements of the fault edges occur due to the difference in the wave parameters in front of and behind the faulting. The obtained data are compared with the “inertia model” calculations and the experimental results. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 56–69. March–April, 2008.     

Change in properties of geophysical medium during underground explosions

Mechanisms of strength loss of rocks in a slightly fractured mass during confined explosions are considered. It is shown that, at small depth (H ≤ 400m) beyond the boundary of radial crack zone, local rock failure is possible under the action of hoop tensile stresses during a single explosion and under the action of shear stresses in wave superposition zones during a group explosion. At great depths, local failure and strength loss of rocks in the indicated area are possible by shear failure in zones of blast wave interaction. Scientific-Research Institute of Labor Protection, Kiev. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 45–50, May–June, 1999     

有耗媒质中任意入射角电磁波传播衰减特性研究

为提高无线电波透视技术的探测精度,给出了含入射角度参数的振幅衰减常数表达式。指出在工作频率和媒质参数一定的前提下振幅衰减常数与电磁波入射角度两者满足正弦关系,在0 ~仔/2区间,振幅衰减常数的值随入射角度的增大而增大。采用改进的振幅衰减常数计算得到的数据进行无线电磁波层析成像,结果表明：改进后的振幅衰减常数计算得到的数据层析成像效果显著优于经典振幅衰减常数得到数据的层析成像效果,层析成像剖面图与实测地质剖面吻合较好。证明了采用改进后的振幅衰减常数可以在一定程度上提高无线电波透视的精度     

Seismic attenuation tomography and its application to rock mass evaluation

We developed two methods of ray-based seismic attenuation tomography. One is amplitude attenuation tomography, which uses amplitude attenuation of the first arrival P-wave. As amplitude is easily influenced by various factors other than viscosity, we removed the effects of velocity structure on wave amplitude, such as transmission loss and diffraction, in the analysis. Decrease of wave frequency during propagation is estimated to obtain the Q-value directly. The other method is pulse broadening tomography, which uses broadening of rise-time or pulse-width of the first arrival P-wave. This method is based on the rise-time principle, which describes pulse broadening with travel time in viscous media. In this method, attenuation information can be obtained by using time data only. The combined use of velocity and attenuation characteristics can be a powerful tool to characterize an in situ rock mass. Therefore we integrated the seismic travel time tomography and the seismic attenuation tomography to a series procedure, and applied it to field data obtained in a mine. The result of travel time tomography agrees with the rock condition estimated by the geological observation at the sites. Faults and fractured zones were detected by the attenuation tomography.     

Features of Low Temperature Effect upon Strength of Enclosing Rock and Kimberlite in the “Udachnaya” Pipe

The effect exerted by low temperatures on the strength of rocks in the “Udachnaya” pipe is investigated. It is shown that the minimal strength corresponds to the temperatures of 268–253 K, which is associated with the processes of water freezing in pores of rocks. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 32–36, March–April, 2005.     

Reasonable reduction in hydrophoby of mineral surface on flotation by carboxylic acids

Numerical estimation of the effect of surfactants on floatability of particles with different wettability is reported. It is proved that the particles with higher hydrophilic surface are recovered into a froth product at the “gas-pulp” interface at the presence of a film of normal alcohols and fat acids. Theoretical value of the suppression coefficient for the capillary wave amplitude coincides satisfactorily with the test values and may be used in calculations. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 5, pp. 90–99, September–October, 2006.     

On attenuation of pendulum-type waves in a block rock mass

The data on experimental and theoretical studies of pendulum wave propagation in a system of steel bars separated by rubber interlayers are reported. The one-dimensional mathematical model, describing the given system as a chain of masses jointed by elastic springs and viscous dampers, is proposed. Numerical calculations are made, and approximate analytical estimates are obtained for attenuation rate of maximum velocities and accelerations of the masses under impact loading of the test system. It is proved that the model adequately describes the disturbance behavior in the system of bars with rubber interlayers. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 5, pp 67–74, September–October, 2006.     

On the use of chemical and bacteriological methods of modifying the properties of highly plastic clay rocks mined by the hydromechanization method

Summary The volume of highly plastic alluvial rocks to be stripped and transported in open-cut mines is very considerable. Present-day methods of working such rocks are inefficient. Particular importance therefore attaches to procedures involving chemical and bacteriological modification of highly plastic clay rocks. After a study of the mechanisms of these processes (which are spontaneous and continuous in nature), a basis would thus be provided for new, highly efficient methods of working highly plastic clay rocks. Bachat Open-Cut Mine of the “Kuzbasskar'eugol” Combine, Belovo. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 5, pp. 125–127, September –October, 1967.     

地质雷达在煤矿井下的应用研究

雷达波的穿透能力大小是衡量雷达在矿井中的应用效果好坏的重要指标，它取决于介质的电磁波衰减系数，衰减系数越小，雷达的穿透能力越大，衰减系数随着介质电导率的增大而增大。煤矿井下介质主要为低电导率的煤层、砂岩、页岩、灰岩，它们的衰减系数较小，雷达波在这些介质中穿透能力较大。     

Estimation of Pillar Stability Based on Viscoelastic Model of Rock Mass

Based on solution to the inverse problem, a procedure is proposed for determining rheological properties of rocks by measurements of relative displacements of pillar walls. The influence exerted by properties of contact with enclosing rocks and shape of a pillar on its stability is analyzed. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 5, pp. 10–17, September–October, 2005.     

Formation of a borehole charge cavity in permanently frozen rocks

A method is considered for borehole charge cavity formation in permanently frozen rocks by delivering a heat carrier into the borehole under pressure in order to thaw the rocks. The calculation of time required for thawing of the latter is provided. Institute of Mining of the North, Siberian Branch, Russian Academy of Sciences, Yakutsk, Russia. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 1, pp. 50–54, January–February, 2000.     

Rock drillability classification. Part II: Canonical representation of rock properties in the rock classification by fracture resistance

A multifactor classification of rocks by drillability is proposed based on canonical representation of the mechanical and structural properties of rocks by the dimensionless characteristics of rock fracture resistance. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6. pp. 86–104, November–December, 2008.     

Rock classification by drillability. Part I: analysis of the available classifications

Based on the quantitative estimations, it is demonstrated that available classifications of rocks by drillability disagree on the scales. Empirical formulae are obtained to compare the scales depending on uniaxial compressive strength of rocks. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 53–62, November–December, 2005.     

Investigation into the long-term strength of rocks under loading with a constant rate

The test data are presented for tensile and compressive strength of some rocks depending on the rate of loading by three-point bending and then uniaxial rigid compression. The constants of Zhurkov’s kinetic equation of durability are determined for the tested rocks. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 37–44, November–December, 2007.     

Determination of Poisson’s ratio in sedimentary rock

It is proposed to determine Poisson’s ratio in sedimentary rocks under unloading with taking into account consolidation of the rock when loaded. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 4, pp. 59–68, July–August, 2006.     

Stress relaxation mechanism in plastic rocks under dynamic loads

It is established that under dynamic loading of plastic rocks relaxation processes are governed by structural, viscous, and migratory mechanisms. The influence of these mechanisms on the phase shift of strains with respect to stresses and on the dynamic aftereffect is analyzed. The interconnection of the manifestation of these mechanisms with the phase composition of rocks is noted. The S. I. Subbotin Institute of Geophysics, National Academy of Sciences, Kiev. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 18–24, March–April, 1999.     

Modeling phenomena of non-stationary heat exchange between mine air and a rock mass

The paper presents a solution to the problem on the non-stationary heat exchange between ventilating air and rocks. The integral relationships for calculating temperatures of air and surrounding rocks are obtained by using the Laplace transforms. Also, their convergence is tested on the example of emergency under reversal of main ventilating facility in a winter period. It is shown that the short-duration heat exchange phenomena should be calculated on the approximation of small times. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 5, pp. 77–85, September–October, 2007.     

Application of the directional hydraulic fracturing at Berezovskaya Mine

The paper analyzes the experimental research of the directional hydraulic fracturing applied for weakening of rocks at Berezovskaya Mine (Kuznetsk Coal Basin) in 2005–2006. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 34–40, May–June, 2008.     

Mechanical Properties of Carboniferous Rocks in the Upper Silesian Coal Basin under Uniaxial and Triaxial Compression Tests

Many years' studies of geological properties or rocks from the Upper Silesian Coal Basin have resulted in acquisition of a substantial data base of mechanical parameters or rocks over the total strain range. It is found that the post-peak rock properties are closely related with the peak strength and the pre-peak properties. The relationship between the uniaxial ultimate strength, elastic modulus, and drop modulus are determined. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 44–48, March–April, 2005.     

地震波在巷道弹塑性围岩中传播规律的数值模拟研究

基于有限元动力分析软件ANSYS/LS-DYNA模拟了地震波在具有初始应力情况下的巷道弹塑性围岩介质中的传播过程,分析了该条件下地震波在巷道周边的传播衰减规律。研究结果表明：随着传播距离的增加,地震波传播呈负指数函数关系衰减;地震波加速度幅值在近源场衰减速度快,远源场衰减减缓;当巷道正前方发生挠动时,随着离巷帮的距离越远,地震波加速度幅值越小;巷道围岩的弹、塑性应力状态也是影响地震波传播过程的一个重要因素,在弹塑性围岩介质中传播时,地震波能量的损耗主要是由于波形的几何扩展和介质的塑性变形引起的。