Effect of borehole charge structure on the parameters of a failure zone in rocks under blasting

The calculation scheme of rock failure under explosion of a borehole charge is presented with account for density of borehole filling with an explosive, availability of air and inert intervals. According to the calculated data, the introduction of air intervals diminishes the specific explosive consumption by 9–27% depending on the explosive power intensity. The similar effect is gained by introducing an inert rod into a borehole charge. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 4, pp. 77–85, July–August, 2007.     

Determination of the filtration properties and stresses in a coal seam by solving the inverse problem

A method is proposed for determining the diffusion coefficient in a coal seam and the horizontal stresses in the enclosing rock on the basis of an algorithm which involves the solution of a class of inverse parabolic problems for regions with a moving boundary. The initial data is the change in gas pressure in a plugged-up borehole. Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 15–22, March–April, 2000.     

Analysis of a borehole driving by a pneumatic puncher

Results are presented for experimental investigation of borehole formation in soils by a pneumatic puncher which make it possible to increase borehole diameters and movement rates. The possiblity is established of determining the energy content for driving according to dynamic densimeter readings. Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 95–100, May–June, 2000.     

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.     

Estimation of temperature field changes in a mass under the stress determination by method of parallel boreholes

Changes in the temperature field and boundary displacements in the measurement borehole are investigated on the basis of a solution of the quasi-static problem of thermoelasticity. An experimental regime that ensures minimum error in the determination of stresses is established. Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 36–41, May–June, 2000.     

Control of longitudinal hydraulic fracturing of wells

An analytical solution is presented for the problem of the hydraulic fracturing of a rock mass by radial cracks. The possibility of controlling longitudinal hydraulic fracturing by creating an initiating slit and uniaxial loading of the walls of a borehole is analyzed. An example is described for the synchronous hydraulic fracturing of a system of parallel boreholes to form a horizontal cavity for an electrohydraulic source of vibration. Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 5, pp. 3–12, September–October, 1999.     

Numerical modeling of hydrofracturing in a multilayer coal seam

The mathematical model of the process for hydrodynamic fracturing in a multilayer coal seam is proposed. The model is based on the equation of continuity and Darcy’s law. The filtration — temperature analogy allows solving the obtained non-linear, non-stationary problem in an axisymmetric statement for the pressure function as the heat-conductivity problem, by the finite-element method. The calculation results yield estimation of the radius of degassing borehole influence zone. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 1, pp. 61–70, January–February, 2006.     

Modeling the explosion of a system of borehole charges in a scarp

Conclusions On the basis of the mathematical model here proposed for the action of the explosion of two cylindrical (borehole) explosive charges in the scarp of a rock mass, the scope for investigating the correlation between wave propagation parameters with scarp rock cutting in a pit is expanded. This offers the possibility of solving a series of problem associated with the correction of wave propagation parameters and their optimization in conditions of open-pit mining of minerals. Mining Institute, Moscow. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 33–38, March–April, 1986.     

Effect of stemming on rock breaking with explosion of a cylindrical charge

A calculation scheme is developed for the destroying action of explosion of a borehole charge in a brittle medium taking account of the ejection of stemming material and outflow of detonation product gases. The influence of different rock and explosive parameters on the efficiency of stemming application is studied. Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 5, pp. 42–52, September–October, 1999.     

Devices for Continuous Recording of the Parameters of Deformation-Wave Processes in Rock Mass. Part III: Probe for Measuring Lateral Borehole Strains and its Design

Design of a probing device to measure lateral borehole strains is presented. The probe is equipped with a data-collection system to support on-line measurements, which is of great importance for the control of stressed rock pillars at underground mines. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 5, pp. 106–113, September–October, 2005.     

Improving the efficiency of soil intake device

A two-mass model is used to study features of the movement of a soil intake device along a horizontal borehole to the face when its drive is operating in the nonpercussive regime. Estimates are made of the transportation speed that can be reached. It is shown that movement of the device in the nonpercussive regime increases its productivity and service life. Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 1, pp. 60–65, January–February, 1999.     

Basis of borehole radiometric defectoscopy for rocks. Part II. Physical modeling

Conclusions We have shown that the distance between cracks can be determined from the distance between the maxima of radiometric logs. With a reduction in probe base there is an increase in the absolute maximum of the anomaly I_γmax with a simultaneous reduction in its width. The width of the maximum I_γmax of the anomaly equals the sum of the probe base and crack opening lengths. Physical and mathematical modeling demonstrates the identical qualitative dependence of recorded γ-radiation on crack parameters. However, in arranging problems of mathematical modeling it is necessary to carry out a laboratory experiment previously with the aim of eliminating unmonitored parameters. The possibility has been demonstrated of using hypotheses 1–4, which lie at the base of a theory for borehole geophysical defectoscopy, for interpreting gamma-gamma ray logging data. Institute of Mining, Siberian Branch, Academy of Sciences of the USSR, Novosibirsk. Translated from Fiziko-tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 5, pp. 35–40, September–October, 1990.     

矿山钻孔三维模型构建与可视化方法

为了建立矿床三维地质模型,研究了基于矿山钻孔数据的钻孔三维模型构建及可视化方法。采用与平台无关的SQLite嵌入式数据库管理钻孔数据,设计了钻孔数据的孔口、样品分析、测斜和地质岩性等4个表结构,分析了建立钻孔三维模型时钻孔数据存在的2种错误类型。将钻孔轨迹曲线转化为折线,给出了均角全距法、全角半距法等2种钻孔轨迹折线计算公式。采用钻孔图形关联属性数据表的数据结构来存储钻孔三维模型,利用点和直线段分别存储钻孔孔口和样品的空间位置数据,数据表存储图形对应的钻孔编号、样品元素品位、体重等属性值。以多段线表示钻孔轨迹,并通过文字、颜色、图形等多种方法实现钻孔属性数据在三维空间的可视化。基于Hoops 3D框架对以上算法进行了实现,并建立了某铜矿32#~56#勘探线钻孔三维模型,根据钻孔轨迹和铜元素品位的可视化结果,圈定了勘探线剖面的铜矿体边界。结果表明,所提出的钻孔三维模型构建方法准确可靠,有助于提高地质分析、矿床地质建模的效率。     

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.     

Features of hydraulic fracture growth in the compression field

The author shows that in case the position of an initial fracture is close to orthogonal relative to the maximum compression direction, the minimum opening of the hydraulic fracture takes place at the contour of borehole. A model problem on fracture propagation along the interface of blocks is solved, and the conditions are found when edges of fractures close. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 19–29, November–December, 2008.     

An automatic hydraulic charger

Summary Our hydraulic charger with independent control of the process of charging a borehole with explosive cartridges has a servo system which determines the duration of transportation of the cartridge along the guide and controls the charging operation. The water pressure is converted to velocity and automatic dosing is effected by a differential valve to correspond with a given duration of the charging process. To reduce the speed of the cartridge when it leaves the guide, the latter is fitted with a hydraulic damper which transmits a pulse to the “command unit” to switch off the feed of pressurized water. Skochinskii Institute of Mining, Moscow. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 1, pp. 103–107, January–February, 1966.     

An Evaluation of Metal Contamination in Surface and Groundwater around a Proposed Uranium Mining Site, Jharkhand, India

The East Singhbhum region is a highly mineralised zone, with extensive mining of copper, uranium, and other minerals. The concentrations of certain metals (Fe, Mn, Zn, Pb, Cu, and Ni) were measured in 10 groundwater locations and eight surface water locations for four seasons during 1 year around a proposed uranium mining area. The ranges of Fe, Mn, Zn, Pb, Cu, and Ni in surface water were 0.08–1.21, 0.02–0.32, 0.02–3.48 mg/L, 0.84–14, 1.25–36, and 1.24–15 μg/L, respectively, while in groundwater, the ranges were 0.06–5.3, 0.01–1.3, 0.02–8.2 mg/L, 1.4–28, 0.78–20, and 1.05–20 μg/L, respectively. Only Fe and Mn were found to exceed India’s drinking water standards. The data have been used to calculate a metal pollution index (MPI). The MPI of both groundwater (28) and surface water (10) is well below the index limit of 100, which suggest that neither is generally contaminated with respect to these metals.     

Stress-strain state of a rock sample with cuts

The singular integral equation is derived for evaluation of normal stresses along the extension of cuts in an elastic domain. The exact solution is found. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 25–31, November–December, 2005.     

Evaluation of the basic parameters of a tunnelling machine with an annular working organ equipped with a pneumatic impact drive

The calculation model for the basic parameters of a tunnelling machine with a working organ of a bypassing type is developed based on the experimental data obtained. The specifications of machines for making holes with a diameter of 325–426 mm by a combined method are substantiated. The test data for a tunnelling machine prototype are reported. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 5, pp. 41–51, September–October, 2007.     

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.