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Seismicity in the Coeur D'Alene mining district, Northern Idaho
266A
Surface subsidence, caving and rockbursts See also." 934234 934466 Preliminary seafloor subsidence values measured over the Phalen Mine 1 West panel, Sydney coalfield, Nova Scotia Aston, T R C; Lapierre, A; Stewart, J M Engng Geol V33, N2, Dec 1992, P85-98 Marine hydrographic surveys were carried out in 1987 and 1988 using echosounder and seismic reflection equipment to map the pre- and post-mining seabed topologies over the Phalen Mine. Equipment, field techniques and data processing are outlined. Measurable subsidence was observed over the West 1 panel and its magnitude is compared to values given by current empirical subsidence prediction methods. Further data should be obtained as mining proceeds, to improve calibration of the prediction formulae. 934467 Rockburst simulation on a physical and numerical model (In German) Muller, W; Vasters, J Gluckauf-forschungsh V53, N4, Aug 1992, P164-168 Attempts are described to simulate the events leading up to a rockburst by simple laboratory physical modelling and by numerical modelling using the F L A C code. In both cases an unstable fracturing movement of the seam was reproduced, accompanied by release of stored strain energy along the separation planes with the surrounding rock. Values returned by the two approaches are in good agreement, suggesting the numerical model can be used for further parametric analysis, with the physical model providing reference points. 934468 Building over abandoned shallow mines. Paper h Considerations of risk and reliability Cole, K Ground Engng V26, N1, Jan~Feb 1993, P34-37 In an earlier paper, risk estimates were made for engineering decisions considering annual risks to life, destruction of property, and bankruptcy. This was for total loss only. The work is now extended to cover additional severities of consequence, impairment and inconvenience. Reliability and perceived attitudes to hazards and reliability are discussed. Subsidence events over shallow mines are introduced and total loss, impairment, and inconvenience ratings as applied to property are evaluated. 934469 Land subsidence in Shanghai (P.R. of China) Monjoie, A; Paepe, R; Su, H Y Int Assoc Engng Geol Bull N46, Oct 1992, P3-5 Detailed study of the upper 70m of Quaternary deposits of the central area of Shanghai reveals units of clay, loam, silt, and sand, with complex geometry reflecting changes in depositional processes. Laboratory and in situ data on hydrogeological and geotechnical properties of the sediments have been collected. Simulation o f subsidence and compaction as a result of groundwater withdrawal has been carried out using the finite element code L A N G A M I N E , which allows detailed representation of the strata, for several pumping/recharge regimes. Maximum subsidence values of 14-79mm have been calculated for the period 1989-2000 and sensitive areas have been identified.
934470 Subsidence effects on embankments: combined empirical-FEM approach. Technical note Drumm, E C; Kane, W F; Orlowski, A C J Geotech Engng Div ASCE 1/119, N1, Jan 1993, P173-17~' Coal spoil is often stored over undermined ground. To ew~luate stability of a coarse refuse embankment over room and pillar workings in two seams in southwest Virginia. anticipated effects of worst case subsidence were evaluated. The Surface Deformation Prediction System (SDPS) was used to predict the subsidence basin for each seam, then displacements were superimposed. Finite element analysis was then used to evaluate deformations, stresses, and potential instabilities induced in the waste embankment. 934471 Remote monitoring of rock mass deformation using time domain reflectometry O'Connor, K M; Dowding, C H Proc 3rd International Symposium on Field Measurements in Geomechaoics, Oslo, 9-11 September 1991 V1, P295-306. Publ Rotterdam. A A Balkema, 1991 TDR, an electrical pulse testing technique originally developed to locate breaks in power transmission cables, has recently been applied to monitor caving above a working seam. Cables are grouted into vertical boreholes ahead of the working face. Automatic, remote, and frequent monitoring of these cables is carried out. Improvements in interpretation of the TDR signatures allows differentiation between breaks, shears, and abrasions, and increases the accuracy with which breaks can be detected. Practical applications in coal and potash mines are illustrated. 934472 Structural characteristics of highly stressed rock masses using microseismic fault-plane solutions Urbancic, T I; Young, R P Proc Conference on Fractured and Jointed Rock Masses, Lake Tahoe, 3-5 June 1992 P241-248. Publ California: Lawrence Berkeley Laboratory, 1992 Fault plane solutions have been obtained for 1093 microseismic events recorded at the Strathcona Mine, Sudbury, in 1987 and 1988. The validity of applying to double-couple (shear failure) model for these events is examined using data from overcoring stress measurements and underground structural mapping. 73% of microseisms appear to fit the double-couple model. The P, B, and T axes and nodal plane orientations evaluated are consistent with mapped fracture sets and principal stress orientations from overcoring. Nodal planes also provide information on which fractures are likely to be active. Microseismic monitoring appears a promising approach for structural characterisation of highly stressed rock masses. 934473 Seismicity in the Coeur D'Alene mining district, Northern Idaho Stevens, G R; Stickney, M C; Sprenke, K F; Jung, S J Proc 28th Symposium on Engineering Geology and Geoteclmical Engineering, Boise, 1-3 April 1992 P266-271. Publ Pocatello: Idaho State University, 1992 Rockburst activity in the Coeur D'Alene district has increased in recent years. The regional stress field is NE-SW extensional, with maximum compressive stress directed NW-SE, generally unfavourable to mining. Short-term survey in 1990 using portable seismometers indicated three patterns of first motion. The dominant mechanism is implosional, although double couple shear events and some events with unsolvable first motion
© 1993 Pergamon Press Ltd. Reproduction not permitted
267A data were also recorded. A permanent network of seismometers which will allow focal plane solutions for all events of magnitude °1.0 will be installed. Information acquired will help understand and mitigate the rockburst problem. 934474 Fundamentals of a practical classification of mining induced seismicity (rock bursts) Knoll, P Proc Fifth International Conference on Soil Dynamics and
Earthquake Engineering, Karlsruhe, 23-26 September 1991 P743-755. Publ Southampton: Computational Mechanics Publications, 1991 An attempt to develop a unified international classification for the complex phenomenon of mining induced seismicity is described. The current state of rockburst classification is outlined. The fundamentals of the new approach are to describe the effects in the mine and to evaluate the interaction between mining technology and the natural geological and tectonic conditions. Draft proposals are presented for the definition of and the process of the rockburst event. 934475 Studies on mechanism of rock bursts-associated seismicity mines by using fractals and damage mechanics Xie, H; Pariseau, W G Proc 33rd US Symposium on Rock Mechanics, Santa Ire, 3-5
stiffness of the tunnel lining are examined. Various case studies of hard rock and soft ground tunnels are considered and the preventive measures adopted against failure as a result of ground movement or liquefaction are described.
934478 Explosion effects in jointed rocks - new insights Heuze, F E; Butkovitich, T R; Walton, O R; Maddix, T M Proc Fifth International Conference on Soil Dynamics and
Earthquake Engineering, Karlsruhe, 23-26 September 1991 P707-718. Publ Southampton: Computational Mechanics Publications, 1991 Hard rock formations are seldom monolithic, and the many geological discontinuities control propagation of ground shock and kinematics of subsequent motions. Discontinuity controlled roof failure of an underground nuclear test chamber is illustrated. Laboratory tests demonstrate the effects of lubricated joints on the ground motion either side of the joint. Discrete Element Analysis is ideal for modelling blocky rock. DIBS (Discrete Interacting Block System) is used to simulate a contained nuclear explosion. The influence of near-source geology on the distribution of energy and the motion at various azimuths is examined.
June 1992 P745-754. Publ Rotterdam: A A Balkema, 1992 Many methods have been used for study and prediction of rockburst, those based on AE monitoring and energy release rate being the most common. Microseismic noise rate alone is not a reliable predictor, but the distribution of event locations is a realistic record of the damage evolution process. A number-radius relation is used to examine distribution of microseismic event location, and a fractal distribution is observed. The fractal nature of the distribution is discussed. The fractal and physical mechanisms of rock burst are analysed using damage mechanics and fractal geometry.
Influence of dynamic loads See also: 934021 934476 Effect of adjoining structures on seismic response of tunnels Navarro, C lnt J Num Anal Meth Geomech V16, NIl, Nov 1992, P797-
934479 Numerical analysis and measurements of the seismic response of galleries Atheid, H J; Hinzen, K G Proc Fifth International Conference on Soil Dynamics and
Earthquake Engineering, Karlsruhe, 23-26 September 1991 P719-730. Publ Southampton: Computational Mechanics Publications, 1991 Rock salt is a candidate host for radioactive waste repositories in Germany. Dynamic response of a gallery in the Asse salt deposit to detonation of chemical explosives was recorded. Test concepts and procedures are described. The test was simulated using the finite element code ANSALT. The kinematic analysis of the generated seismic waveforms allows comparison of effects of different geometries. Comparison of measured and calculated responses constrains material inhomogeneities close to the gallery. Results are examined against those of an earlier experiment in dolomite.
814 The finite element code F L U S H is used to study the seismic behaviour of buried rectangular two-barrel concrete tunnels subject to vertically propagating P and S waves. The effects of massive surface structures, representing nuclear power plant buildings, on response are investigated. The following cases are considered: tunnel in free field conditions; tunnel near building founded at surface level; tunnel between buildings founded at different depths; and tunnel adjacent to deeply founded massive building. Results are compared to those computed using an alternative simplified methodology. 934477 Tunnelling in seismic zones Rowe, R
Tuna Tunnlg V24, N12, Dec 1992, P41-44 A brief overview of earlier assessments of seismically-induced damage to tunnels and the various damage mechanisms involved is presented. Earthquake loading and the required
Subjects Peripheral to Geomechanics 934480 Geosynthetic containments in environmental protection Sadlier, M A Aust Geomech N22, July 1992, P39-43 Geosynthetic materials have many applications in areas such as landfill leachate containment, liners, and caps. The systems used are reviewed with emphasis on American experiences, and use in areas characterised by monsoon flooding, poor soil conditions, and high water table is discussed. Liner and cap materials and their testing and use of geotextiles for puncture prevention and drainage are considered.
© 1993 Pergamon Press Ltd. Reproduction not permitted
Surface subsidence, caving and rockbursts See also." 934234 934466 Preliminary seafloor subsidence values measured over the Phalen Mine 1 West panel, Sydney coalfield, Nova Scotia Aston, T R C; Lapierre, A; Stewart, J M Engng Geol V33, N2, Dec 1992, P85-98 Marine hydrographic surveys were carried out in 1987 and 1988 using echosounder and seismic reflection equipment to map the pre- and post-mining seabed topologies over the Phalen Mine. Equipment, field techniques and data processing are outlined. Measurable subsidence was observed over the West 1 panel and its magnitude is compared to values given by current empirical subsidence prediction methods. Further data should be obtained as mining proceeds, to improve calibration of the prediction formulae. 934467 Rockburst simulation on a physical and numerical model (In German) Muller, W; Vasters, J Gluckauf-forschungsh V53, N4, Aug 1992, P164-168 Attempts are described to simulate the events leading up to a rockburst by simple laboratory physical modelling and by numerical modelling using the F L A C code. In both cases an unstable fracturing movement of the seam was reproduced, accompanied by release of stored strain energy along the separation planes with the surrounding rock. Values returned by the two approaches are in good agreement, suggesting the numerical model can be used for further parametric analysis, with the physical model providing reference points. 934468 Building over abandoned shallow mines. Paper h Considerations of risk and reliability Cole, K Ground Engng V26, N1, Jan~Feb 1993, P34-37 In an earlier paper, risk estimates were made for engineering decisions considering annual risks to life, destruction of property, and bankruptcy. This was for total loss only. The work is now extended to cover additional severities of consequence, impairment and inconvenience. Reliability and perceived attitudes to hazards and reliability are discussed. Subsidence events over shallow mines are introduced and total loss, impairment, and inconvenience ratings as applied to property are evaluated. 934469 Land subsidence in Shanghai (P.R. of China) Monjoie, A; Paepe, R; Su, H Y Int Assoc Engng Geol Bull N46, Oct 1992, P3-5 Detailed study of the upper 70m of Quaternary deposits of the central area of Shanghai reveals units of clay, loam, silt, and sand, with complex geometry reflecting changes in depositional processes. Laboratory and in situ data on hydrogeological and geotechnical properties of the sediments have been collected. Simulation o f subsidence and compaction as a result of groundwater withdrawal has been carried out using the finite element code L A N G A M I N E , which allows detailed representation of the strata, for several pumping/recharge regimes. Maximum subsidence values of 14-79mm have been calculated for the period 1989-2000 and sensitive areas have been identified.
934470 Subsidence effects on embankments: combined empirical-FEM approach. Technical note Drumm, E C; Kane, W F; Orlowski, A C J Geotech Engng Div ASCE 1/119, N1, Jan 1993, P173-17~' Coal spoil is often stored over undermined ground. To ew~luate stability of a coarse refuse embankment over room and pillar workings in two seams in southwest Virginia. anticipated effects of worst case subsidence were evaluated. The Surface Deformation Prediction System (SDPS) was used to predict the subsidence basin for each seam, then displacements were superimposed. Finite element analysis was then used to evaluate deformations, stresses, and potential instabilities induced in the waste embankment. 934471 Remote monitoring of rock mass deformation using time domain reflectometry O'Connor, K M; Dowding, C H Proc 3rd International Symposium on Field Measurements in Geomechaoics, Oslo, 9-11 September 1991 V1, P295-306. Publ Rotterdam. A A Balkema, 1991 TDR, an electrical pulse testing technique originally developed to locate breaks in power transmission cables, has recently been applied to monitor caving above a working seam. Cables are grouted into vertical boreholes ahead of the working face. Automatic, remote, and frequent monitoring of these cables is carried out. Improvements in interpretation of the TDR signatures allows differentiation between breaks, shears, and abrasions, and increases the accuracy with which breaks can be detected. Practical applications in coal and potash mines are illustrated. 934472 Structural characteristics of highly stressed rock masses using microseismic fault-plane solutions Urbancic, T I; Young, R P Proc Conference on Fractured and Jointed Rock Masses, Lake Tahoe, 3-5 June 1992 P241-248. Publ California: Lawrence Berkeley Laboratory, 1992 Fault plane solutions have been obtained for 1093 microseismic events recorded at the Strathcona Mine, Sudbury, in 1987 and 1988. The validity of applying to double-couple (shear failure) model for these events is examined using data from overcoring stress measurements and underground structural mapping. 73% of microseisms appear to fit the double-couple model. The P, B, and T axes and nodal plane orientations evaluated are consistent with mapped fracture sets and principal stress orientations from overcoring. Nodal planes also provide information on which fractures are likely to be active. Microseismic monitoring appears a promising approach for structural characterisation of highly stressed rock masses. 934473 Seismicity in the Coeur D'Alene mining district, Northern Idaho Stevens, G R; Stickney, M C; Sprenke, K F; Jung, S J Proc 28th Symposium on Engineering Geology and Geoteclmical Engineering, Boise, 1-3 April 1992 P266-271. Publ Pocatello: Idaho State University, 1992 Rockburst activity in the Coeur D'Alene district has increased in recent years. The regional stress field is NE-SW extensional, with maximum compressive stress directed NW-SE, generally unfavourable to mining. Short-term survey in 1990 using portable seismometers indicated three patterns of first motion. The dominant mechanism is implosional, although double couple shear events and some events with unsolvable first motion
© 1993 Pergamon Press Ltd. Reproduction not permitted
267A data were also recorded. A permanent network of seismometers which will allow focal plane solutions for all events of magnitude °1.0 will be installed. Information acquired will help understand and mitigate the rockburst problem. 934474 Fundamentals of a practical classification of mining induced seismicity (rock bursts) Knoll, P Proc Fifth International Conference on Soil Dynamics and
Earthquake Engineering, Karlsruhe, 23-26 September 1991 P743-755. Publ Southampton: Computational Mechanics Publications, 1991 An attempt to develop a unified international classification for the complex phenomenon of mining induced seismicity is described. The current state of rockburst classification is outlined. The fundamentals of the new approach are to describe the effects in the mine and to evaluate the interaction between mining technology and the natural geological and tectonic conditions. Draft proposals are presented for the definition of and the process of the rockburst event. 934475 Studies on mechanism of rock bursts-associated seismicity mines by using fractals and damage mechanics Xie, H; Pariseau, W G Proc 33rd US Symposium on Rock Mechanics, Santa Ire, 3-5
stiffness of the tunnel lining are examined. Various case studies of hard rock and soft ground tunnels are considered and the preventive measures adopted against failure as a result of ground movement or liquefaction are described.
934478 Explosion effects in jointed rocks - new insights Heuze, F E; Butkovitich, T R; Walton, O R; Maddix, T M Proc Fifth International Conference on Soil Dynamics and
Earthquake Engineering, Karlsruhe, 23-26 September 1991 P707-718. Publ Southampton: Computational Mechanics Publications, 1991 Hard rock formations are seldom monolithic, and the many geological discontinuities control propagation of ground shock and kinematics of subsequent motions. Discontinuity controlled roof failure of an underground nuclear test chamber is illustrated. Laboratory tests demonstrate the effects of lubricated joints on the ground motion either side of the joint. Discrete Element Analysis is ideal for modelling blocky rock. DIBS (Discrete Interacting Block System) is used to simulate a contained nuclear explosion. The influence of near-source geology on the distribution of energy and the motion at various azimuths is examined.
June 1992 P745-754. Publ Rotterdam: A A Balkema, 1992 Many methods have been used for study and prediction of rockburst, those based on AE monitoring and energy release rate being the most common. Microseismic noise rate alone is not a reliable predictor, but the distribution of event locations is a realistic record of the damage evolution process. A number-radius relation is used to examine distribution of microseismic event location, and a fractal distribution is observed. The fractal nature of the distribution is discussed. The fractal and physical mechanisms of rock burst are analysed using damage mechanics and fractal geometry.
Influence of dynamic loads See also: 934021 934476 Effect of adjoining structures on seismic response of tunnels Navarro, C lnt J Num Anal Meth Geomech V16, NIl, Nov 1992, P797-
934479 Numerical analysis and measurements of the seismic response of galleries Atheid, H J; Hinzen, K G Proc Fifth International Conference on Soil Dynamics and
Earthquake Engineering, Karlsruhe, 23-26 September 1991 P719-730. Publ Southampton: Computational Mechanics Publications, 1991 Rock salt is a candidate host for radioactive waste repositories in Germany. Dynamic response of a gallery in the Asse salt deposit to detonation of chemical explosives was recorded. Test concepts and procedures are described. The test was simulated using the finite element code ANSALT. The kinematic analysis of the generated seismic waveforms allows comparison of effects of different geometries. Comparison of measured and calculated responses constrains material inhomogeneities close to the gallery. Results are examined against those of an earlier experiment in dolomite.
814 The finite element code F L U S H is used to study the seismic behaviour of buried rectangular two-barrel concrete tunnels subject to vertically propagating P and S waves. The effects of massive surface structures, representing nuclear power plant buildings, on response are investigated. The following cases are considered: tunnel in free field conditions; tunnel near building founded at surface level; tunnel between buildings founded at different depths; and tunnel adjacent to deeply founded massive building. Results are compared to those computed using an alternative simplified methodology. 934477 Tunnelling in seismic zones Rowe, R
Tuna Tunnlg V24, N12, Dec 1992, P41-44 A brief overview of earlier assessments of seismically-induced damage to tunnels and the various damage mechanisms involved is presented. Earthquake loading and the required
Subjects Peripheral to Geomechanics 934480 Geosynthetic containments in environmental protection Sadlier, M A Aust Geomech N22, July 1992, P39-43 Geosynthetic materials have many applications in areas such as landfill leachate containment, liners, and caps. The systems used are reviewed with emphasis on American experiences, and use in areas characterised by monsoon flooding, poor soil conditions, and high water table is discussed. Liner and cap materials and their testing and use of geotextiles for puncture prevention and drainage are considered.
© 1993 Pergamon Press Ltd. Reproduction not permitted