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1.
The hydrogeomechanical problems of mining are considered, which deal with rocks and ground water as a single mechanical system.
Among these problems are the openpits slopes stability, rocks consolidation and surface subsidence due to ground water level
lowering, water inrushes into mine workings, rock bursts prevention by using the water injection into the advance boreholes,
etc. The paper contains the basic theoretical grounds, as well as in-situ and laboratory methods for the investigation of
these processes.
The combined study of ground water regime and rock deformations has resulted in the theoretical substantiation of the hydrodynamic
and geomechanical processes within the scope of unique scientific direction-hydrogeomechanics (Mironenko, 1974). The hydrogeomechanical
models are widely used now for the analysis and forecasting the extremely important processes connected with the safe and
efficient mining operations, as well as with the protection of geological medium. Among these processes are:
相似文献
– | o deformations of the open-pit slopes and spoil dumps; |
– | o consolidation of rocks due to the ground-water pressure drop; |
– | o water-and-rock material inrushes into mine workings caused by deformations of the undermined rock mass; |
– | o geodynamical processes due to the changes in ground water regime; |
– | o artificial hydrofracturing in rocks; |
– | o transformations of clay linings under the tailing ponds and other technical water basins |
2.
1. | The experiments that we conducted made it possible to ascertain the significant variation in the deformation and rheologic properties of a fissured mass as compared with the monolith. The crack frequency, the number of jointing systems, the strength and deformation properties of the monolith, and the magnitude of the effective stresses exert an influence on the degree of variation in these parameters. |
2. | In designing systems of excavations and calculating the expected deformations of the rock mass in mine workings, it is necessary to consider not only the strength reduction, but also the variation in its rheologic properties. |
3. | The investigation of the mechanical properties of a fissured mass on models of equivalent materials provides for adequate prediction of the properties of the actual mass. |
3.
4.
Paul L Younger 《Mine Water and the Environment》2000,19(2):84-97
During the 1990s, passive treatment technology was introduced to the United Kingdom (UK). Early hesitancy on the part of regulators
and practitioners was rapidly overcome, at least for net-alkaline mine waters, so that passive treatment is now the technology
of choice for the long-term remediation of such discharges, wherever land availability is not unduly limiting. Six types of
passive systems are now being used in the UK for mine water treatment:
Each of these technologies is appropriate for a different kind of mine water, or for specific hydraulic circumstances. The
degree to which each type of system can be considered “proven technology” corresponds to the order in which they are listed
above. Many of these passive systems have become foci for detailed scientific research, as part of a $1.5M European Commission
project running from 2000 to 2003. 相似文献
– | ♦ aerobic, surface flow wetlands (reed-beds); |
– | ♦ anaerobic, compost wetlands with significant surface flow; |
– | ♦ mixed compost/limestone systems, with predominatly subsurface flow (so-calledReducing andAlkalinityProducingSystems (RAPS)); |
– | ♦ subsurface reactive barriers to treat acidic, metalliferous ground waters; |
– | ♦ closed-system limestone dissolution systems for zinc removal from alkaline waters; |
– | ♦ roughing filters for treating ferruginous mine waters where land availability is limited. |
5.
1. | A new model is suggested with simple techniques representing the dynamic behavior of an assembled support system at intersections of horizontal mine workings. Plastic behavior of the material at the conjugation points of structural elements is taken into account. |
2. | Equations systems are formulated to calculate the behavior of a support system sustaining static and dynamic rock pressures. |
3. | In case of a dynamic impact upon the support system at a conjugation, the greatest strength is attained when the rigidity of the external medium is higher than that of the medium filling the space between the support systems of the individual workings. |
4. | When a plane wave acts upon the support system at the conjugation, the internal support system removed from the wavefront at the initial time is especially susceptible to breakdown. |
5. | Support systems interact not only in terms of vibration amplitude but also vibration frequency and form. The influence of internal support systems upon the external support system is particularly strong. |
6.
1. | The distribution of lumps by mass is a complementary structural-statistical lumpiness characteristic that makes it possible to ascertain more clearly certain laws governing the process of fragment formation as compared with the distribution of lumps by size. |
2. | A Weibull-type equation provides good approximation of unimodal curves of mass distribution for the different conditions considered for the multiple fracture of rigid bodies. |
3. | There are characteristic points about which values of the distribution-shape parameter are grouped: the shape parameter is close to 1/3 for the impact failure of lumps and the crushing of specimens, and to 1/2 for the case of explosive crushing. |
4. | An increasing in the end surcharge of tubular rock specimens failed by blasting leads to a reduction in the shape parameter for the fine fractions and to diminution of the bimodality effect. |
5. | Use of the operation of the additional opening of blast-induced cracks in weakened lumps of semimetallic ore is reflected in geometrically similar transformations of the distribution curves in the direction of a reduction in lump mass. |
6. | As applies to the blast-induced failure of brittle plates, a functional relationship between the mass of the fragments and the reduced distance to the blast center is obtained by statistical averaging; for small values of the argument, the latter is approximated by the fourth power of the reduced distance. |
7.
1. | Rock possesses the ability to accumulate energy at the microlevel and release it at the macrolevel under certain conditions. This property may reside in a number of basic properties characteristic for rock, such as cohesion, internal friction, and dilatancy. As a result, individual sections of a rock mass may play the role of energy sources and flows. |
2. | A specimen composed of thin roughened rods tied together by an elastic band can be used as an element modeling the property of energy accumulation. Uniaxial compression of the specimen is accompanied by softening jumps and acoustic emission. This energy may be released under appropriate conditions (vibration, minor thrusting). |
3. | Within certain limits, this element can be used as a physical experimental rock model. In this case, the plane model of a rock mass may consist of a set of these elements with different reserves of initial accumulated energy. |
8.
Calculating the aerogas dynamics of chamber-like mine workings on the basis of mathematical modeling
1. | The sufficiently high reliability of the standard (k-ε) model for the Reynolds-stress in calculating the velocity field in plane chamber-like mine workings has been demonstrated. | ||||
2. | A version of the velocity-field calculation in plane chambers by the Smagorinskii model has been proposed, using the (k-ε) model in the preliminary stage, so as to permit considerable reduction in computer time. | ||||
3. |
The most rational finite-difference schemes for approximation of the advection term in the turbulent-diffusion equation when
estimating the air transfer in plane chamber-like workings have been recommended:
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4. | It is shown that scheme V (Table 2) has high schematic viscosity in a nonuniform velocity field, and therefore cannot be used to calculate flows in chambers with complex geometry. | ||||
5. | Using the numerical modeling of the physical fields (air velocity and impurity concentration) in a ventilated volume proposed here permits the determination either of the time to achieve the maximum permissible concentration with specified contamination-source intensities and air flow rates or the air flow rate required in a specified ventilation time. |
9.
Conclusions
Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk. Translated from Fiziko-Tekhnicheskie Problemy
Razrabotki Poleznykh Iskopaemykh, Vol. 34, No. 3, pp.101–107, May–June, 1998. 相似文献
1. | The ultimate size of bubbles in a flotation cell is an outcome of competing processes: coalescence of bubbles and adsorption of the surfactant on their surface. |
2. | Formation of highly developed initial interface due to breakup of the gas phase is an indispensable condition for stabilizing bubble size at a lower size level. |
3. | The optimal method of frothing agent injection (for stabilizing bubble size) into the flotation cell is to inject it into the air phase as vapors or aerosols. |
10.
1. | Cavity elimination technology by isolation and filling with low-strength materials has been used successfully in working mineral resources by underground mines, including beds of complex structure. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
2. | The technicoeconomic and social effectiveness of cavity elimination that preserves the surface of the earth and the environmental setting in the area surrounding the mines and the utilization of production wastes and low-quality local mineral resources endow these technologies with a conservation-oriented value and open new prospects for their use. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
3. | Scientific and engineering principles of resource-saving cavity elimination technologies and years of practical experience with them should be considered by designers of plans for development of new deposits in mining fields across the country. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
4. |
Tested methods of material quality improvement are recommended for large-scale introduction in mining and related industries:
11.
E. L. Kreimer 《Journal of Mining Science》1989,25(6):560-566
12.
Conclusions The following characteristics of self-transportation have been established.
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Conclusions
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Conclusions
16.
W. F. Heinz 《Mine Water and the Environment》1988,7(4):1-12
Pre-cementation or pre-grouting of deep shafts in South Africa is an established technique to improve safety and reduce water
ingress during shaft sinking. The recent completion of several pre-cementation projects for shafts deeper than 1000m has once
again highlighted the effectiveness of pre-grouting of shafts utilizing deep slimline boreholes and incorporating wireline
technique for drilling and conventional deep borehole grouting techniques for pre-cementation.
Pre-cementation of deep shaft will:
17.
V. N. Kulakov 《Journal of Mining Science》1998,34(6):529-536
Conclusions
18.
A. M. Kovrizhnykh 《Journal of Mining Science》1990,26(4):321-331
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