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Survey of mining associated seismicity
68A able to simulate intensity of microseismicity in a longwall panel, variation with face advance, and distribution of microseisms. 921526 Fuzzy mathematics method for theoretical analysis of ground movements due to underground excavation Li, W Min Sci Technoi VI3, NI, July 1991, P45-56 Because of the complexity of the problem, it is difficult to calculate accurately ground movements due to underground mining. A new method for subsidence estimation is presented, based on the fuzzy probability theory of fuzzy mathematics. The concepts of fuzzy probability are described and their application to practical engineering problems demonstrated. Predicted ground movements over 5 mines in China agree well with measured data, indicating the value of this new approach. 921527 Decreasing coal bump risk through optimal cut sequencing with a non-linear boundary element program Zipf, R K; Heasley, K A Rock Mechanics Contributions and Challenges: Proc 31st US Symposium, Golden, 18-20 June 1990 P947-954. Publ Rotterdam: A A Balkema, 1990 Violent outburst can occur during the retreat mining phase in room and pillar mining when levels of stress in pillars adjacent to the gob reach their maximum. Risks of bumps can be minimised by selection of proper mining sequence. The nonlinear boundary element program MULSIM/NL has been designed for this purpose. Six stress strain relations can be used. A subroutine ERR calculates the energy release rate for different mining sequences. Olga Mine, single split and fender, pocket and wing, and open ending methods are compared as to their proneness to bumps. 921528 Rock burst mechanism studies at the Lucky Friday Mine Jenkins, F M; Williams, T J; Wideman, C J Rock Mechanics Contributions and Challenges: Proc 31st US Symposium, Golden, 18-20 June 1990 P955-962. Publ Rotterdam: A A Balkema, 1990 Rockburst poses particular safety problems in strong brittle rock masses when narrow tabular orebodies are worked to high extraction ratio. Four major causes of rockburst have been identified: surface instability at or near the stope face; shear fractures propagating ahead of the face; pillar collapse; and slip along geologic structures. Microseismic monitoring and analysis of data using the XDETECT program have been used to establish which of these mechanisms is responsible for the outbursts at the Lucky Friday Mine in Idaho. 921529 Some estimates of rockburst danger in underground coal mines based on the energy of microseismic events Lasocki, S Proc 4th Conference on Acoustic gmissionIMicroseismic Activity in Geological Structures and Materials, Pennsylvania, 22-24 October 1985 P617-633. Publ Clausthal-Zellerfeld: Trans Tech Publications, 1989 The energy distribution of rockburst shocks in some Polish coal mines has been analysed and found to fit a log-log relation. An attempt is made to predict the probability of a strong shock, exceeding a given energy, from the energy distribution observed in a preceding period. Two methods of probability
evaluation are used, least squares fit, and direct e~aluat~on or the constants in the Pareto relation previously derived. Practical evaluation with field data of this and other methods of rockburst prediction is examined. 921530 Comparison between two significant cases of subsidence due to fluid withdrawals: Bologna and Ravenna (Northern Italy) Borgia, G C; Brighenti, G; Mesini, E Proc 6th International Congress International Association o f Engineering Geology, Amsterdam, 6-10 August 1990 V2. P1333-1340. Pub[ Rotterdam: A A Balkema, 1990 Subsidence around two towns in the Po valley has been analysed. The different nature of the subsidence and its relation to hydrological and geological conditions and the height above sea level are discussed. Fluid withdrawal is considered to be the primary cause of the sinking. Remedial and preventative measures are described. 921531 Quantitative study of land subsidence in Shanghai Gu, X Y; Gong, S L; Huang, H C; Liu, Y Proc 6th International Congress International Association o f Engineering Geology, Amsterdam, 6-10 August 1990 I/2. P1363-1370. Publ Rotterdam: A A Balkema, 1990 Land subsidence assessment in Shanghai City indicates the withdrawal of groundwater as the main cause. Whilst control measures including restriction of pumping groundwater have reduced the subsidence, the 2-3mm annual subsidence still occurring requires further attention. Computational analysis using appropriate soil parameters indicated that increasing recharging alone is not the sole measure needed. The subsidence is partially related to secondary consolidation and remedial measures must take this into account. 921532 Dynamic boundary element method for modelling rockbnrsts Mack, M G; Crouch, S L Proc 2nd International Symposium on Rockbursts and Seismicity in Mines, Minneapolis, 8-10 June 1988 P93-99. Publ Rotterdam: A A Balkema, 1990 A boundary element model for computing dynamic displacements and stresses caused by sudden changes in the excavation geometry or by sudden slip on a plane of weakness is presented. The model is based on the dynamic displacement discontinuity method. This method is introduced through simplified examples, restricted to a single plane and simple materials. A simple mining problem is modelled by considering a 40m by 10m room in a horizontal plane, suddenly advanced by tm. 921533 Survey of mining associated seismicity Johnston, J C; Einstein, M H Proc 2nd International Symposium on Rockbursts and Seismicity in Mines, Minneapolis, 8-10 June 1988 P121-127. Publ Rotterdam." A A Balkema, 1990 Factors influencing mining-induced seismicity across the world have been surveyed. Rockbursts and associated seismicity were sorted according to geology and pre-existing stress field. Two broad classes are separated: seismicity related to mining activity and geometry (controlled by local fracturing) and that occurring on existing faults, more similar to natural seismicity. Reliability of prediction of maximum size of earthquake based on mine and geological factors is assessed for different regions.
© 1992 Pergamon Press plc. Reproduction not permitted
evaluation are used, least squares fit, and direct e~aluat~on or the constants in the Pareto relation previously derived. Practical evaluation with field data of this and other methods of rockburst prediction is examined. 921530 Comparison between two significant cases of subsidence due to fluid withdrawals: Bologna and Ravenna (Northern Italy) Borgia, G C; Brighenti, G; Mesini, E Proc 6th International Congress International Association o f Engineering Geology, Amsterdam, 6-10 August 1990 V2. P1333-1340. Pub[ Rotterdam: A A Balkema, 1990 Subsidence around two towns in the Po valley has been analysed. The different nature of the subsidence and its relation to hydrological and geological conditions and the height above sea level are discussed. Fluid withdrawal is considered to be the primary cause of the sinking. Remedial and preventative measures are described. 921531 Quantitative study of land subsidence in Shanghai Gu, X Y; Gong, S L; Huang, H C; Liu, Y Proc 6th International Congress International Association o f Engineering Geology, Amsterdam, 6-10 August 1990 I/2. P1363-1370. Publ Rotterdam: A A Balkema, 1990 Land subsidence assessment in Shanghai City indicates the withdrawal of groundwater as the main cause. Whilst control measures including restriction of pumping groundwater have reduced the subsidence, the 2-3mm annual subsidence still occurring requires further attention. Computational analysis using appropriate soil parameters indicated that increasing recharging alone is not the sole measure needed. The subsidence is partially related to secondary consolidation and remedial measures must take this into account. 921532 Dynamic boundary element method for modelling rockbnrsts Mack, M G; Crouch, S L Proc 2nd International Symposium on Rockbursts and Seismicity in Mines, Minneapolis, 8-10 June 1988 P93-99. Publ Rotterdam: A A Balkema, 1990 A boundary element model for computing dynamic displacements and stresses caused by sudden changes in the excavation geometry or by sudden slip on a plane of weakness is presented. The model is based on the dynamic displacement discontinuity method. This method is introduced through simplified examples, restricted to a single plane and simple materials. A simple mining problem is modelled by considering a 40m by 10m room in a horizontal plane, suddenly advanced by tm. 921533 Survey of mining associated seismicity Johnston, J C; Einstein, M H Proc 2nd International Symposium on Rockbursts and Seismicity in Mines, Minneapolis, 8-10 June 1988 P121-127. Publ Rotterdam." A A Balkema, 1990 Factors influencing mining-induced seismicity across the world have been surveyed. Rockbursts and associated seismicity were sorted according to geology and pre-existing stress field. Two broad classes are separated: seismicity related to mining activity and geometry (controlled by local fracturing) and that occurring on existing faults, more similar to natural seismicity. Reliability of prediction of maximum size of earthquake based on mine and geological factors is assessed for different regions.
© 1992 Pergamon Press plc. Reproduction not permitted