- Email: [email protected]
Rock mass characterization at Tara zinc-lead mine, Eire
293A White Austin Limestone and at the WIPP (bedded salt). Several aspects were examined closely: use of an exponential window during data acquisition, effects of discontinuities on dispersion, and near surface variations in blasted and mined rock masses.
935195 Modeling of lateral spreads in silty sands by sliding soil blocks Dobry, R; Baziar, M Proc Conference Stability and Performance of Slopes and Embankments II, Berkeley, 29 Jane-I July 1992 VI, P625652. Publ New York: ASCE, 1992 (ASCE Special Geotechnical Publication No 31) Lateral spreading associated with liquefaction is a common cause of damage for gently sloping granular deposits during earthquakes. A model of rigid sliding soil blocks is proposed to analyse this phenomenon. Significant factors and failure mechanisms are examined. Variation of post-failure shear strength with depth has been investigated in laboratory tests on layered silty sand. Parametric studies are described. Two methods which give good predictions of ground displacement are presented, one based on earthquake records, the other requiring attenuation relations for peak ground velocity and acceleration.
935196 Modulus dispersion and attenuation in tuff and granite Haupt, R W; Martin, R J; Tang, X; Dupree, W J; Price, R H Proc 33rd US Symposium on Rock Mechanics, Santa Fe, 3-5 June 1992 P899-908. Publ Rotterdam: A A Balkema, 1992 Effects of loading frequency, strain amplitude, and saturation on elastic moduli and attenuation of Topopah Spring Member tuff have been examined. Four different laboratory techniques were used across the frequency range 0.01-700kHz. Similar data were obtained for Sierra White granite. Moduli and attenuation are relatively frequency-independent for room dry specimens. Frequency effects, attributed to fluid flow and sample size, are seen in saturated samples. The tuff samples showed no dependence on strain amplitude across the range employed.
935197 Modeling of the elastic properties of a schistose rock from seismic measurements Hesler, G J; Cook, N G W; Myer, L R Proc 33rd US Symposium on Rock Mechanics, Santa Fe, 3-5 June 1992 P909-915. Publ Rotterdam: A A Balkema, 1992 Specimens were taken from schistose rock retrieved at the Grimsel site, Switzerland, with axes perpendicular to and parallel to the foliation. Seismic tests were carried out at frequencies 100-1000kHz, axial stresses 2.42-38.72 MPa, at orientations 30 deg apart, to characterise the elastic parameters of the rock. Hudson's (1981) equations were used to determine crack parameters. Good agreement was found between parameters calculated from velocity information for waves of different types and orientation. Attenuation coefficients from spectral data show a first order relation with frequency as opposed to fourth order predicted by Hudson.
935198 Study on the transmission of shear waves across thin liquid films and thin clay layers Suarez-Rivera, F R; Cook, N G W; Myer, L R Proc 33rd US Symposium on Rock Meclumics, Santa Fe, 3-5 June 1992 P937-946. Publ Rotterdam: A A Balkema, 1992 Ultrasonic shear wave propagation across thin films of various liquids was investigated. Amplitude of the transmitted wave did not always increase with ratio of liquid viscosity to film thickness, as theory predicts. It is proposed that this is related to chemical composition of the liquids and how they react with quartz surfaces. Interface attenuation, rather than internal attenuation, may dominate. Corresponding experiments were carried out using thin layers of montmorillonite clay with large surface areas. Results can be explained according to the theory of displacement-and-velocity discontinuity and are useful in predicting the behaviour of natural clay interfaces.
Identification and classification 935199 Criterion for quick evaluation of excavation behaviour through geomechanical classification (In Italian and English) Grasso, P; Russo, G; Xu, S; Pelizza, S Gallerie V15, N39, March 1993, P26-34 Geomechanical classifications provide useful empirical design tools for the engineer. A criterion for rapid evaluation of rock mass behaviour, based on the comparison of the stress state of the excavation profile and strength characteristics of the rock mass from the corresponding RMR value, has been developed by the Italian Railway Authority. Both long term (tunnel) and short term (face) stability can be estimated. The method is of particular use for deep tunnels. Case applications are presented. 935200 Rock mass characterization at Tara zinc-lead mine, Eire Trueman, R; Pine, R J; Villard, P; Tyler, D B; Fry, R Proc ISRM Symposium: Eurock'92, Chester, 14-17 September 1992 P251-256. Publ London: Thomas Telford, 1992 In order to predict the response of rock during and after mining, anisotropic characteristics must be quantified. Intact rock strength can be directly assessed and Q and RMR rock mass classification systems can be used to quantify the anisotropy of the rock mass. Mine design should take into account the anisotropic nature of the rock involved. The case of a failed pillar in strong limestone at the Tara Mine is presented, where rock mass strength was well predicted by the anisotropic models developed. 935201 Ground assessment for the construction of large underground excavations at Ashanti Goldfields Corporation (GH) Limited, Ghana Suorineni, F T Proc 7th ISRM International Congress on Rock Mechanics, Aachen, 16-20 September 1991 V2, P1213-1216. Publ Rotterdam: A A Balkema, 1991 It is planned to extend a 5,5m diameter shaft from the 24 Level (853m) to the 52 Level to allow rapid development of high quality quartz orebodies. An access drive and exploration boreholes indicated the need for careful site characterisation for construction of the shaft and ancillary structures. Rock mass classification according to RMR, mining-modified RMR, and Q systems was used to characterise the ground and
© 1993 Pergamon Press Ltd. Reproduction not permitted
294A in support specification. Rock quality is generally poor, requiring intensive support in the large openings. A circular shaft design has replaced the original rectangular one.
In Situ Stress Measurement of in situ stress See also: 935418
935202 Interpretation of horizontal and mixed-mode fractures in hydraulic fracturing tests in rocks Hefny, A; Lo, K Y Can Geotech J V29, N6, Dec 1992, P902-917 Hydraulic fracturing stress measurements are the only practical method at great depth. Exact solutions for calculating the stress already exist for the case of vertical fractures. Closed form solutions are presented for horizontal and mixed mode fractures including strength anisotropy. The method allows determination of which fracture occurs first at the first breakdown, so appropriate stress calculations can be carried out. Re-analysis of case histories shows significantly lower stresses computed for horizontal fractures than given by previous analyses. Field observations in underground structures provide some verification of the new analysis. 935203 Obtaining the minimum horizontal stress from microfracture test data: a new approach using a derivative algorithm Jones, C; Sargeant, J P SPE Prod Facil V8, N1, Feb 1993, P39-44 A new approach to interpret pressure decline data from microfracture tests, to determine closure pressure and hence minimum horizontal stress, is presented. It uses a derivative algorithm to identify the different flow regimes occurring (wellbore storage, infinite and finite conductivity fracture flow). It requires quality input data but is easy to use. Successful application to data from the North Sea is illustrated, for rocks from near-impermeable claystone to porous sandstone. 935204 PC-based data acquisition and analysis software for hydraulic fracturing stress measurements Lee, M Y; Haimson, B C Proe 3rd International Symposium on Field Measurements in Geomeehanies, Oslo, 9-11 September 1991 V1, P455-464. Publ Rotterdam." A A Balkema, 1991 The H F U W software package for acquisition and interpretation of hydraulic fracturing field data is presented. It contains 3 major modules: digital data acquisition, statistical data analysis, and in situ stress calculation. The stress calculation can be by conventional elastic or poroelastic models based on plane strain analysis or by the fracture pressurization method, based on the theory of stress alone. Screen readouts during the test/computation stages are illustrated.
Site Investigation and Field Observation See: 935355
Remote sensing and photographic techniques 935205 Characterization of lava-flow degradation in the Pisgah and Cima volcanic fields, California, using Landsat Thematic Mapper and AIRSAR data Arvidson, R E; Shepard, M K; Guiness, E A; Petroy, S B; Plaut, J J; Evans,D L; Farr, T G; Greeley, R; Lancaster, N; Gaddis, L R Bull Geol Soc Am VI05, N2, Feb 1993, P175-184 Analysis is presented of TM and A I R S A R (radar) data and microtopographic profiles from airborne photography from the Mojave Remote Sensing Field Experiment. TM radiance factors are primarily related to smoothing by wasting and infill by fine grained aeolian deposits and to surface roughness generated by fluvial dissection. A I R S A R data are primarily influenced by surface roughness.
Geophysical techniques See also: 935194
935206 Gamma-ray logging of outcrops by a truck-mounted sonde. Geologic note Jordan, D W; Slatt, R M; Gillespie, R H; D'Agostino, A E; Stone, C G Bull Am Assoe Petrol Geol V77, NI, Jan 1993, P118-123 An innovative method for gamma-ray logging of rock outcrops is presented. A standard sonde is lowered to the base of the outcrop, then raised at a constant rate with gamma-ray measurements continuously recorded. Logging rate is lower than in boreholes, as the tool is exposed to less rock mass in the case of outcrops. Examples of application of this technique and its results are illustrated, and potential and pitfalls of the method are discussed. 935207 Influence of lithology and Neogene uplift on seismic velocities in Denmark: Implications for depth conversion of maps Jaspen, P Bull Am Assoe Petrol Geol V77, N2, Feb 1993, P194-211 The concept of velocity anomaly, the deviation between measured velocity and that from a regional linear-velocity function for a formation, is introduced. Factors affecting the velocity anomaly are related to geological processes. Contoured maps of velocity anomaly can be interpreted to provide information on lithology and post-depositional history of sedimentary rock. Application to provision of reliable depth maps in northern Denmark is illustrated. 935208 Fracture statistics derived from digital ultrasonic televiewer logging Schmitt, D R Can Pet Teehnol V32, N2, Feb 1993, P34-43 Fractures in a 300m section of core from a highly fractured igneous formation are compared with digital televiewer wireline logging images obtained by mapping the amplitudes and travel times of ultrasonic pulses. Results show the travel time log features are indicative of in situ fractures which are described by other methods as open and permeable. Orientation of the travel time features correlates with expected direction of stress. Care must be taken when inferring fracture type (shear or extensional) from the geophysical data.
© 1993 Pergamon Press Ltd. Reproduction not permitted
935195 Modeling of lateral spreads in silty sands by sliding soil blocks Dobry, R; Baziar, M Proc Conference Stability and Performance of Slopes and Embankments II, Berkeley, 29 Jane-I July 1992 VI, P625652. Publ New York: ASCE, 1992 (ASCE Special Geotechnical Publication No 31) Lateral spreading associated with liquefaction is a common cause of damage for gently sloping granular deposits during earthquakes. A model of rigid sliding soil blocks is proposed to analyse this phenomenon. Significant factors and failure mechanisms are examined. Variation of post-failure shear strength with depth has been investigated in laboratory tests on layered silty sand. Parametric studies are described. Two methods which give good predictions of ground displacement are presented, one based on earthquake records, the other requiring attenuation relations for peak ground velocity and acceleration.
935196 Modulus dispersion and attenuation in tuff and granite Haupt, R W; Martin, R J; Tang, X; Dupree, W J; Price, R H Proc 33rd US Symposium on Rock Mechanics, Santa Fe, 3-5 June 1992 P899-908. Publ Rotterdam: A A Balkema, 1992 Effects of loading frequency, strain amplitude, and saturation on elastic moduli and attenuation of Topopah Spring Member tuff have been examined. Four different laboratory techniques were used across the frequency range 0.01-700kHz. Similar data were obtained for Sierra White granite. Moduli and attenuation are relatively frequency-independent for room dry specimens. Frequency effects, attributed to fluid flow and sample size, are seen in saturated samples. The tuff samples showed no dependence on strain amplitude across the range employed.
935197 Modeling of the elastic properties of a schistose rock from seismic measurements Hesler, G J; Cook, N G W; Myer, L R Proc 33rd US Symposium on Rock Mechanics, Santa Fe, 3-5 June 1992 P909-915. Publ Rotterdam: A A Balkema, 1992 Specimens were taken from schistose rock retrieved at the Grimsel site, Switzerland, with axes perpendicular to and parallel to the foliation. Seismic tests were carried out at frequencies 100-1000kHz, axial stresses 2.42-38.72 MPa, at orientations 30 deg apart, to characterise the elastic parameters of the rock. Hudson's (1981) equations were used to determine crack parameters. Good agreement was found between parameters calculated from velocity information for waves of different types and orientation. Attenuation coefficients from spectral data show a first order relation with frequency as opposed to fourth order predicted by Hudson.
935198 Study on the transmission of shear waves across thin liquid films and thin clay layers Suarez-Rivera, F R; Cook, N G W; Myer, L R Proc 33rd US Symposium on Rock Meclumics, Santa Fe, 3-5 June 1992 P937-946. Publ Rotterdam: A A Balkema, 1992 Ultrasonic shear wave propagation across thin films of various liquids was investigated. Amplitude of the transmitted wave did not always increase with ratio of liquid viscosity to film thickness, as theory predicts. It is proposed that this is related to chemical composition of the liquids and how they react with quartz surfaces. Interface attenuation, rather than internal attenuation, may dominate. Corresponding experiments were carried out using thin layers of montmorillonite clay with large surface areas. Results can be explained according to the theory of displacement-and-velocity discontinuity and are useful in predicting the behaviour of natural clay interfaces.
Identification and classification 935199 Criterion for quick evaluation of excavation behaviour through geomechanical classification (In Italian and English) Grasso, P; Russo, G; Xu, S; Pelizza, S Gallerie V15, N39, March 1993, P26-34 Geomechanical classifications provide useful empirical design tools for the engineer. A criterion for rapid evaluation of rock mass behaviour, based on the comparison of the stress state of the excavation profile and strength characteristics of the rock mass from the corresponding RMR value, has been developed by the Italian Railway Authority. Both long term (tunnel) and short term (face) stability can be estimated. The method is of particular use for deep tunnels. Case applications are presented. 935200 Rock mass characterization at Tara zinc-lead mine, Eire Trueman, R; Pine, R J; Villard, P; Tyler, D B; Fry, R Proc ISRM Symposium: Eurock'92, Chester, 14-17 September 1992 P251-256. Publ London: Thomas Telford, 1992 In order to predict the response of rock during and after mining, anisotropic characteristics must be quantified. Intact rock strength can be directly assessed and Q and RMR rock mass classification systems can be used to quantify the anisotropy of the rock mass. Mine design should take into account the anisotropic nature of the rock involved. The case of a failed pillar in strong limestone at the Tara Mine is presented, where rock mass strength was well predicted by the anisotropic models developed. 935201 Ground assessment for the construction of large underground excavations at Ashanti Goldfields Corporation (GH) Limited, Ghana Suorineni, F T Proc 7th ISRM International Congress on Rock Mechanics, Aachen, 16-20 September 1991 V2, P1213-1216. Publ Rotterdam: A A Balkema, 1991 It is planned to extend a 5,5m diameter shaft from the 24 Level (853m) to the 52 Level to allow rapid development of high quality quartz orebodies. An access drive and exploration boreholes indicated the need for careful site characterisation for construction of the shaft and ancillary structures. Rock mass classification according to RMR, mining-modified RMR, and Q systems was used to characterise the ground and
© 1993 Pergamon Press Ltd. Reproduction not permitted
294A in support specification. Rock quality is generally poor, requiring intensive support in the large openings. A circular shaft design has replaced the original rectangular one.
In Situ Stress Measurement of in situ stress See also: 935418
935202 Interpretation of horizontal and mixed-mode fractures in hydraulic fracturing tests in rocks Hefny, A; Lo, K Y Can Geotech J V29, N6, Dec 1992, P902-917 Hydraulic fracturing stress measurements are the only practical method at great depth. Exact solutions for calculating the stress already exist for the case of vertical fractures. Closed form solutions are presented for horizontal and mixed mode fractures including strength anisotropy. The method allows determination of which fracture occurs first at the first breakdown, so appropriate stress calculations can be carried out. Re-analysis of case histories shows significantly lower stresses computed for horizontal fractures than given by previous analyses. Field observations in underground structures provide some verification of the new analysis. 935203 Obtaining the minimum horizontal stress from microfracture test data: a new approach using a derivative algorithm Jones, C; Sargeant, J P SPE Prod Facil V8, N1, Feb 1993, P39-44 A new approach to interpret pressure decline data from microfracture tests, to determine closure pressure and hence minimum horizontal stress, is presented. It uses a derivative algorithm to identify the different flow regimes occurring (wellbore storage, infinite and finite conductivity fracture flow). It requires quality input data but is easy to use. Successful application to data from the North Sea is illustrated, for rocks from near-impermeable claystone to porous sandstone. 935204 PC-based data acquisition and analysis software for hydraulic fracturing stress measurements Lee, M Y; Haimson, B C Proe 3rd International Symposium on Field Measurements in Geomeehanies, Oslo, 9-11 September 1991 V1, P455-464. Publ Rotterdam." A A Balkema, 1991 The H F U W software package for acquisition and interpretation of hydraulic fracturing field data is presented. It contains 3 major modules: digital data acquisition, statistical data analysis, and in situ stress calculation. The stress calculation can be by conventional elastic or poroelastic models based on plane strain analysis or by the fracture pressurization method, based on the theory of stress alone. Screen readouts during the test/computation stages are illustrated.
Site Investigation and Field Observation See: 935355
Remote sensing and photographic techniques 935205 Characterization of lava-flow degradation in the Pisgah and Cima volcanic fields, California, using Landsat Thematic Mapper and AIRSAR data Arvidson, R E; Shepard, M K; Guiness, E A; Petroy, S B; Plaut, J J; Evans,D L; Farr, T G; Greeley, R; Lancaster, N; Gaddis, L R Bull Geol Soc Am VI05, N2, Feb 1993, P175-184 Analysis is presented of TM and A I R S A R (radar) data and microtopographic profiles from airborne photography from the Mojave Remote Sensing Field Experiment. TM radiance factors are primarily related to smoothing by wasting and infill by fine grained aeolian deposits and to surface roughness generated by fluvial dissection. A I R S A R data are primarily influenced by surface roughness.
Geophysical techniques See also: 935194
935206 Gamma-ray logging of outcrops by a truck-mounted sonde. Geologic note Jordan, D W; Slatt, R M; Gillespie, R H; D'Agostino, A E; Stone, C G Bull Am Assoe Petrol Geol V77, NI, Jan 1993, P118-123 An innovative method for gamma-ray logging of rock outcrops is presented. A standard sonde is lowered to the base of the outcrop, then raised at a constant rate with gamma-ray measurements continuously recorded. Logging rate is lower than in boreholes, as the tool is exposed to less rock mass in the case of outcrops. Examples of application of this technique and its results are illustrated, and potential and pitfalls of the method are discussed. 935207 Influence of lithology and Neogene uplift on seismic velocities in Denmark: Implications for depth conversion of maps Jaspen, P Bull Am Assoe Petrol Geol V77, N2, Feb 1993, P194-211 The concept of velocity anomaly, the deviation between measured velocity and that from a regional linear-velocity function for a formation, is introduced. Factors affecting the velocity anomaly are related to geological processes. Contoured maps of velocity anomaly can be interpreted to provide information on lithology and post-depositional history of sedimentary rock. Application to provision of reliable depth maps in northern Denmark is illustrated. 935208 Fracture statistics derived from digital ultrasonic televiewer logging Schmitt, D R Can Pet Teehnol V32, N2, Feb 1993, P34-43 Fractures in a 300m section of core from a highly fractured igneous formation are compared with digital televiewer wireline logging images obtained by mapping the amplitudes and travel times of ultrasonic pulses. Results show the travel time log features are indicative of in situ fractures which are described by other methods as open and permeable. Orientation of the travel time features correlates with expected direction of stress. Care must be taken when inferring fracture type (shear or extensional) from the geophysical data.
© 1993 Pergamon Press Ltd. Reproduction not permitted