- Email: [email protected]
Mine-induced seismicity at East rand proprietary mines
EXCAVATIONS:DYNAMIC LOADS Activity balances for these nuclides were constructed for the overall operation of the mine and yellow cake plant. All the ~6Ra resulting from ore exploitation is presently contained in the Borst t~.~lings pile. However, because of the very high content of ~ in red mud deposited at Jazbee, where 60% of this nuclide, is found, the majority of 226Ra will be found at the Jazbec pile in the future, due to its ingrowth from 230Th over the next few thousand years. The long-term radioecological consequences of this untypical finding for rehabilitation of the site, and its safe management are discussed. (from Authors)
961350 Qualitative and quantitative variations of the groundwaters from the vicinity of Tarnobrzeg resulting from sulphur mining J. Malinowski & M. Perek, Kwartalnik Geologiczny, 38(3), 1994, pp 593-601. The groundwaters of the Quaternary horizon have become quantitatively and qualitatively degraded over an area of about 150 km 2 of underground sulphur melting in Jeziorko and in the open pit Machow. Within the mining fields of Jeziorko and nearby areas the groundwaters display an increase in the content of sulphates and chlorides resulting from the pumping of salt waters into the Tertiary beds. The sulphates and chlorides which penetrate the groundwaters within the quaternary sediments, are quickly diluted and their extent is limited. After complete exploitation of the Jeziorko mine the groundwaters of Quaternary deposits may retrieve their primary quality. (Authors) 961351 Contamination of groundwater in the Te Aroha area by heavy metals from an abandoned mine Liping Pang, Journal of Hydrology (New Zealand), 33(1), 1995, pp 17-34. Groundwater contamination from the copper/lead Tui mine was investigated by modelling the groundwater flow regime, monitoring groundwater quality, and studying the retention of heavy metal contaminants by the lithologic units of the receiving environments. Metal concentrations in the groundwater define a leachate plume extending approximately 1 km downgradient of the tailings pond. The contaminated groundwater discharges to surface mountain streams which in turn recharge and contaminate groundwater in downgradient alluvial fans. The volume and timing of contaminant desorption from the tailings for each of the heavy metals indicates the tailings will be a pollution source for hundreds to thousands of years. (from Author) 961352 Establishment of wetland ecosystems in lakes created by mining in Western Australia J. M. Chambers & A. J. McComb, in: Global wetlands, ed W.J. Mitseh, (Elsevier Science), 1994, pp 431-441. A 4-kin chain of lakes created by sand-mining for rare metals near Capel, Western Australia, is being developed into a wetland ecosystem. This paper briefly describes the development of the wetlands and then concentrates on investigations into propagation and habitat preferences of emergent aquatic macrophytes. (from Authors) 961353 New technique for removing metals from waste water R. Sambasivan, Journal of Scientific & Industrial Research, 53(11), 1994, pp 881-882. An environmentally benign technique for removing and recovering metals and minerals from waste water has recently been developed. The technique being inexpensive could be of economic advantage in cleaning up open pit mines such as the Berkeley Pit, Bulte (Montana). (Authors) 961354 Raw deal A. Oliver, New Civil Engineer (NCE), 1132, 1995, pl0.
43A
This short article describes the effects of a major sewer renewal project in Deal, Kent on its residents. The tunnelling works have caused months of inconvenience caused by road closures and traffic diversions not to mention a trail of destruction, including listing properties, subsided roads, broken sewers and burst pipes. (C.Paice)
Subsidence, caving and rockbursts 961355 Photogrammetric monitoring of deformation caused by mine subsidence P. Davies & J. Fryer, Australian Survey, 40(1), 1995, pp 5-9. A photogrammetric survey was carded out in the Lithgow area of New South Wales, to monitor the movement of rock masses under the influence of longwall mining. The task was to determine three dimensional coordinates of a number of target points on the subject rock masses with respect to time, such that the rock movements could be modelled as the longwall face passed below. In the area of interest, it was anticipated that both subsidence and lateral movements would be in the order of one metre. (from Authors) 961356 Reinforcing sidewalls and corners of gateway to control floor heave (in Chinese) Hou Chaojiong, He Yanan, Li Xiao, Hou Lihong & Yao Guoping, Journal - China Coal Society, 20(3), 1995, pp 229234. The basic principles for control of floor heave are studied. A new method is proposed to reinforce the sidewalls and corners (mainly the lower corners) in soft and weak rocks in gateway for control of floor heave. Numerical analysis using computer and simulation test show that reinforcement of different positions of the gateway will help to control the floor heave. When the load is less than 1.9 MPa, the results of reinforcement of roof and floor are good. When the load is greater than 1.9 MPa, the results of reinforcement of the sidewalls are good. Underground commercial tests are made in Liuxin and Huangtangling Mines. (English summary)
Influence of dynamic loads 961357 Optimal spatial distribution of seismic stations in mines A. Kijko & M. Sciocatti, International Journal of Rock Mechanics & Mining Sciences, 32(6), 1995, pp 607-615. The optimality criterion is derived from the theory of optimal experiment. The approach allows: different probability of event occurrence at different mining areas; planning for the best estimates of selected parameters as for example epicenter coordinates, and building a network that is optimal for location of seismic events within a specified range of seismic energy. Four applications, two hypothetical and two in mines in Canada and in South Africa show that the proposed procedure provides a powerful and useful tool. (from Authors)
961358 Mine-induced seismicity at East Rand Proprietary Mines A. M. Milev, S. M. Spottiswoode & K. R. Noble, International Journal of Rock Mechanics & Mining Sciences, 32(6), 1995, pp 629-632. For detailed analysis, the active regions of the mine were divided into sub-regions around specified seismogenic volumes. The sub-regions sizes were determined from the following: 1) the seismicity associated with face advance; 2) the stress activity on abutments and pillars; 3) the local geological features. A linear relation between seismieity and elastic closure is simplified as EM0 = yGAVM where EM0 is cumulative seismic moment; A VM was estimated from the volume of rock mined out assuming a stope width of 1.1 m; Y is a factor which can vary between 0 and 1; G is the modulus
44A
PERIPHERAL SUBJECTS:FRACTURE MECHANICS
of ridigity, which is asmnned from laboratory measurements to be 3.0 x 101° N/m 2. The right side of equation: 1) is a measure of seismic failure in response to shear stress which are caused by the volume change. GAVM represents the volumetric moment, 7 is the ratio of cumulative seismic moment to volumetric moment, interpreted as being dependent on the local geology. (from Authors)
961359 A stationary model for time-dependent seismic hazard in mining G. Finnie, Acta Geophysical Polonica, 42(2), 1994, pp 111118. A strategy to determine the probability that a mining-induced seismic event will occur with a magnitude that exceeds some specified value within a given time is presented. The model which is based on a non-linear frequency-magnitude relationship and a Poissonian distribution of seismic events in time, is applied to a region comprising seven mines and some 650 km 2 in extent. The results appear to be remarkably good in view of the simplicity of the model. (from Author)
PERIPHERAL SUBJECTS ,Fracture mechanics 961360 A mechanism for the production of electromagnetic radiation during fracture of brittle materials S. G. O'Keefe & D. V. Thiel, Physics of the Earth & Planetary Interiors, 89(1-2), 1995, pp 127-135. The feasibility of the charge separation model as the source of electromagnetic radiation received from the fracture of brittle materials is demonstrated. An analytical expression and a finite difference method enable the calculation of currents flowing around the tip of a crack. Results from the model compare favourably with fracture events recorded from ice samples. Changes in material conductivity affect pulse shape although changes in crack surface conductance and not crack apex conductance cause most variation in the received signal. (Authors)
961350 Qualitative and quantitative variations of the groundwaters from the vicinity of Tarnobrzeg resulting from sulphur mining J. Malinowski & M. Perek, Kwartalnik Geologiczny, 38(3), 1994, pp 593-601. The groundwaters of the Quaternary horizon have become quantitatively and qualitatively degraded over an area of about 150 km 2 of underground sulphur melting in Jeziorko and in the open pit Machow. Within the mining fields of Jeziorko and nearby areas the groundwaters display an increase in the content of sulphates and chlorides resulting from the pumping of salt waters into the Tertiary beds. The sulphates and chlorides which penetrate the groundwaters within the quaternary sediments, are quickly diluted and their extent is limited. After complete exploitation of the Jeziorko mine the groundwaters of Quaternary deposits may retrieve their primary quality. (Authors) 961351 Contamination of groundwater in the Te Aroha area by heavy metals from an abandoned mine Liping Pang, Journal of Hydrology (New Zealand), 33(1), 1995, pp 17-34. Groundwater contamination from the copper/lead Tui mine was investigated by modelling the groundwater flow regime, monitoring groundwater quality, and studying the retention of heavy metal contaminants by the lithologic units of the receiving environments. Metal concentrations in the groundwater define a leachate plume extending approximately 1 km downgradient of the tailings pond. The contaminated groundwater discharges to surface mountain streams which in turn recharge and contaminate groundwater in downgradient alluvial fans. The volume and timing of contaminant desorption from the tailings for each of the heavy metals indicates the tailings will be a pollution source for hundreds to thousands of years. (from Author) 961352 Establishment of wetland ecosystems in lakes created by mining in Western Australia J. M. Chambers & A. J. McComb, in: Global wetlands, ed W.J. Mitseh, (Elsevier Science), 1994, pp 431-441. A 4-kin chain of lakes created by sand-mining for rare metals near Capel, Western Australia, is being developed into a wetland ecosystem. This paper briefly describes the development of the wetlands and then concentrates on investigations into propagation and habitat preferences of emergent aquatic macrophytes. (from Authors) 961353 New technique for removing metals from waste water R. Sambasivan, Journal of Scientific & Industrial Research, 53(11), 1994, pp 881-882. An environmentally benign technique for removing and recovering metals and minerals from waste water has recently been developed. The technique being inexpensive could be of economic advantage in cleaning up open pit mines such as the Berkeley Pit, Bulte (Montana). (Authors) 961354 Raw deal A. Oliver, New Civil Engineer (NCE), 1132, 1995, pl0.
43A
This short article describes the effects of a major sewer renewal project in Deal, Kent on its residents. The tunnelling works have caused months of inconvenience caused by road closures and traffic diversions not to mention a trail of destruction, including listing properties, subsided roads, broken sewers and burst pipes. (C.Paice)
Subsidence, caving and rockbursts 961355 Photogrammetric monitoring of deformation caused by mine subsidence P. Davies & J. Fryer, Australian Survey, 40(1), 1995, pp 5-9. A photogrammetric survey was carded out in the Lithgow area of New South Wales, to monitor the movement of rock masses under the influence of longwall mining. The task was to determine three dimensional coordinates of a number of target points on the subject rock masses with respect to time, such that the rock movements could be modelled as the longwall face passed below. In the area of interest, it was anticipated that both subsidence and lateral movements would be in the order of one metre. (from Authors) 961356 Reinforcing sidewalls and corners of gateway to control floor heave (in Chinese) Hou Chaojiong, He Yanan, Li Xiao, Hou Lihong & Yao Guoping, Journal - China Coal Society, 20(3), 1995, pp 229234. The basic principles for control of floor heave are studied. A new method is proposed to reinforce the sidewalls and corners (mainly the lower corners) in soft and weak rocks in gateway for control of floor heave. Numerical analysis using computer and simulation test show that reinforcement of different positions of the gateway will help to control the floor heave. When the load is less than 1.9 MPa, the results of reinforcement of roof and floor are good. When the load is greater than 1.9 MPa, the results of reinforcement of the sidewalls are good. Underground commercial tests are made in Liuxin and Huangtangling Mines. (English summary)
Influence of dynamic loads 961357 Optimal spatial distribution of seismic stations in mines A. Kijko & M. Sciocatti, International Journal of Rock Mechanics & Mining Sciences, 32(6), 1995, pp 607-615. The optimality criterion is derived from the theory of optimal experiment. The approach allows: different probability of event occurrence at different mining areas; planning for the best estimates of selected parameters as for example epicenter coordinates, and building a network that is optimal for location of seismic events within a specified range of seismic energy. Four applications, two hypothetical and two in mines in Canada and in South Africa show that the proposed procedure provides a powerful and useful tool. (from Authors)
961358 Mine-induced seismicity at East Rand Proprietary Mines A. M. Milev, S. M. Spottiswoode & K. R. Noble, International Journal of Rock Mechanics & Mining Sciences, 32(6), 1995, pp 629-632. For detailed analysis, the active regions of the mine were divided into sub-regions around specified seismogenic volumes. The sub-regions sizes were determined from the following: 1) the seismicity associated with face advance; 2) the stress activity on abutments and pillars; 3) the local geological features. A linear relation between seismieity and elastic closure is simplified as EM0 = yGAVM where EM0 is cumulative seismic moment; A VM was estimated from the volume of rock mined out assuming a stope width of 1.1 m; Y is a factor which can vary between 0 and 1; G is the modulus
44A
PERIPHERAL SUBJECTS:FRACTURE MECHANICS
of ridigity, which is asmnned from laboratory measurements to be 3.0 x 101° N/m 2. The right side of equation: 1) is a measure of seismic failure in response to shear stress which are caused by the volume change. GAVM represents the volumetric moment, 7 is the ratio of cumulative seismic moment to volumetric moment, interpreted as being dependent on the local geology. (from Authors)
961359 A stationary model for time-dependent seismic hazard in mining G. Finnie, Acta Geophysical Polonica, 42(2), 1994, pp 111118. A strategy to determine the probability that a mining-induced seismic event will occur with a magnitude that exceeds some specified value within a given time is presented. The model which is based on a non-linear frequency-magnitude relationship and a Poissonian distribution of seismic events in time, is applied to a region comprising seven mines and some 650 km 2 in extent. The results appear to be remarkably good in view of the simplicity of the model. (from Author)
PERIPHERAL SUBJECTS ,Fracture mechanics 961360 A mechanism for the production of electromagnetic radiation during fracture of brittle materials S. G. O'Keefe & D. V. Thiel, Physics of the Earth & Planetary Interiors, 89(1-2), 1995, pp 127-135. The feasibility of the charge separation model as the source of electromagnetic radiation received from the fracture of brittle materials is demonstrated. An analytical expression and a finite difference method enable the calculation of currents flowing around the tip of a crack. Results from the model compare favourably with fracture events recorded from ice samples. Changes in material conductivity affect pulse shape although changes in crack surface conductance and not crack apex conductance cause most variation in the received signal. (Authors)