Measuring equipment and test bench to control evolution of acoustic-deformation and heat fields induced in solids under failure by fluids

The authors have developed a procedure and a test bench for studying evolution of various nature physical fields in modeling geomedium fracture by fluids. The test bench performs synchronous recording of macro- and micro-deformation, heat and acoustic emission induced in physical models of geomedium under loading to discontinuity. The experimental procedure has been trialed. The analysis of the synchronized test data allows a conclusion on the existence of time–space relationship between different nature physical fields induced during failure of solids.     

Types of orebodies on the basis of the occurrence depth and stress state. Part II: Orebody tectonotypes and geomedium models

The author has accomplished systematization of ore fields by their geomechanical conditions based on the analysis of their tectonic structures. It is established that natural stress fields in the same type geological and tectonic structures are similar in mining regions worldwide. The author has distinguished four geomedium models differentiating the change of the rock stress state with increase in the rock occurrence depth.     

Modeling of anisotropic fissuring process in rocks

A mathematical model is offered to describe thermofluctuation processes of plastic deformation and fissuring in a geomedium. The kinetic coefficients are functions of temperature, mean pressure and stress deviator intensity.     

Failure Features of One-Dimensional Model of Block Media under Sustained Uniaxial Loading

It is established experimentally that, in block geomedia, under conditions of sustained (months) uniaxial loading, the normal tension cracks can appear and develop under the action of stresses which are less than the ultimate strength in uniaxial compression of the corresponding geomaterial samples by an order. The features distinguished in the experiment on failure of one-dimensional block model of geomedium are compared with the results of visual and instrumental observations of failure character of the ore masses of the Talnakh-Oktyabrsky deposit.     

Deformation-wave processes under production face advance in coal and rocks

The article shows the deformation-wave behavior of geomechanical processes induced by coal production face advance. The enclosing rock mass response to mining is interpreted as the formation of a hierarchy of geomedium elements in the continuum subject to excess elastic energy behind the front of the vertical stress decrease. Parameters of the physical model of the process are given in terms of minetechnical situations.     

Using the Kaiser Effect in Composites for Stressed Rock Mass Control

Stress memory in consolidating composites in acoustic emission is studied experimentally to understand feasibility of its application in stress state control in rock mass. The tests show that, owing to uniformity and comparatively high responsiveness of acoustic emission behavior under straining, composite materials, when placed in a geomedium, allow highly accurate identification of tensor of actual stresses in it.     

Transient one-dimensional wave processes in a layered medium

Waveguide properties of a block geomedium are studied by using a regular structure composed of elastic layers with elastic inertialess interlayers. The analytical solution of the problem is derived. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 41–54, March–April, 2007.     

Effect of air distribution profile on selectivity at zinc cleaner circuit

Airflow rate to a cell is one of the main operating variables in flotation. In many plants, if measurements are available at all, they are typically made on a line common to several cells with valves to distribute as determined by the operator. In this study, air distribution throughout zinc cleaner circuit of CBI was adjusted to three different profiles. These are “as found” which was the original profile adjusted by operators, “decreasing” and “increasing” profiles which were adjusted for test. It was seen that air distribution profile significantly affected flotation selectivity. Selectivity between both sphalerite–pyrite and sphalerite–chalcopyrite increased with “increasing” profile. The effect of air distribution profile on flotation selectivity was also studied at mini pilot plant (MPP). Zinc rougher concentrate was taken as feed of MPP. Air distribution profile was adjusted and controlled by airflow meters of each cell. Three different air profiles; “balanced”, “decreasing” and “increasing”, were tested. The results of MPP tests also confirmed that “increasing” air distribution profile improved selectivity at zinc cleaner circuit.     

瑞利波泄漏模式与“之”字形正演模拟

对瑞利波勘探中泄漏模式波的求取问题进行模拟研究.通过添加附加层的方法，使实频散方程求解瑞利波相速度的范围包含所有的层速度区域，从而可用导波来模拟计算泄漏模式波.从模拟结果来看，附加层法不仅能模拟出原模型的实数导波，还能计算出其泄露模式波的变化；同时，通过计算vr-λ频散曲线，说明泄漏模式波的存在也是产生“之”字形现象的原因之一.     

CFD modelling and simulation of industrial-scale copper electrorefining process

Both electrolyte flow and cupric ion concentration fields have been numerically calculated with the computational fluid dynamics (CFD) model in an industrial-scale copper electrorefining cell. In this CFD model, both of the natural convection induced by the electrochemical reactions and the forced convection caused by the electrolyte circulation are taken into account. In order to examine how the difference in the ways of the electrolyte circulation affects the electrolyte flow pattern associated with the concentration field, three different ways of the electrolyte circulation, “bottom inlet to top outlet”, “top inlet to bottom outlet”, and “side inlet to top outlet”, have been modeled.Calculation results have revealed that both “bottom inlet to top outlet” and “top inlet to bottom outlet” circulations have characteristic flow patterns that are locally formed near the inlet. On the other hand, “side inlet to top outlet” circulation forms the inherent two vortex tubes in the space below the electrodes. It is also found that the electrolyte flow patterns in the inter-electrode spaces are formed mainly by the natural convection, and they are insensitive to kinds of the electrolyte circulation way.     

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.     

Elastic Wave Propagation in Block Medium under Impulse Loading

The waveguide properties of a block medium are studied by an example of a discrete-periodical system of spring-connected rods. As a particular case, a chain of masses is considered. It is shown that in the rod system, impulse loading excites two groups of nonstationary waves. The velocities of their propagation are determined. The asymptotic representation is obtained for low-frequency wave at a great period of time since the process onset. The analytical estimations of excitation spectrum are derived.     

From the alternating-sign explosion response of rocks to the pendulum waves in stressed geomedia. Part II

The article reviews research and development results in the sphere of designing unique apparatuses and equipment for modeling and in situ recording of nonlinear elastic waves and associated electro-magnetic emission in block-hierarchical rock masses in the condition of high stresses. The joint experimental outcomes and theoretical research findings gained by leading institutions of the Russian Academy of Sciences and its branches within recent decades, in the framework of integration interdisciplinary projects offer the methodology and instrumentation support for new promising systems of integrated geomechanical and geophysical monitoring of mining-induced earthquakes and rockbursts in Russian mines that may act as unique natural “laboratories” for both academic and applied research in geosciences.     

"人机环管"在煤矿供电安全管理中的应用

制定供电过程中消除安全隐患的针对性措施,可以为矿井安全生产提供必要保障。为探究煤矿供电管理中安全隐患的具体分析方法,首先介绍“人机环管”管理体系的建立过程和核心内容,接着以“人机环管”的管理方法分析了供电管理中的普遍问题。在分析供电管理中的具体问题时,分别得出了“人”“机”“环”“管”4方面的具体措施。分析认为,“人机环管”方法可以有效查找出存在的安全隐患,进而保证煤矿供电系统的安全可靠。     

Anomalies of low-intensity acoustic wave attenuation in rocks

It is experimentally established that acoustic waves in rocks attenuate abnormally depending on varying amplitude. The amplitude growth results in the increase in elastic wave velocities and decrease in the attenuation decrement. The attenuation rather than wave velocity is more sensitive to the amplitude variations. The obtained data are applicable to diagnose the states of fractured and porous rocks. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 4, pp. 24–31, July–August, 2008.     

最大主应力方向对围岩偏应力及变形影响研究

地应力是引起巷道变形破坏的主要因素之一,为了分析最大主应力方向对围岩稳定的影响,采用FLAC3D模拟了夹角α从0°～90°过程中围岩塑性区分布、偏应力及位移变化规律。研究结果认为：α越大,“围岩”塑性区范围越大,且有向顶、底板围岩深部发展的趋势|围岩偏应力呈“单峰”状,顶、底板围岩偏应力峰值随α增大而增大,而帮部偏应力峰值则减小|围岩位移变化呈类“线性”增长,围岩变形随α增大而增大,最大水平主应力方向对顶、底板围岩变形的影响大于帮部。通过现场观测,验证了分析结果的可靠性。     

Automated System for Physical Modeling of the Stress-Strain State of Block Structures in Geomedium

Development of construction principles and creation of automated systems for physical modeling of the block geomedium behavior in the varying unequally component stress field are considered currently as one of the strategic problems in nonlinear geomechanics. The scheme of stand for physical modeling and measuring-computational equipment oriented to the solution for fundamental problems of geomechanics are presented.     

Estimate of Stress-Strain State of Rocks in the Area of Drilling Kola Ultradeep Well

The values of horizontal tectonic stresses are estimated up to depth of 11 500 m by the measurement of velocities of longitudinal and transverse waves in rock samples extracted from various depths when drilling Kola Ultradeep Well.