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Identification and characterisation of sets of fractures and faults in rock
327A
Composition, structure texture and density See also: 906018, 906241
906031 Quantitative coal mineralogy of the Sydney Coalfield, Nova Scotia, Canada,by scanning electron microscopy, computerised image analysis, and energy dispersive X-ray spectrometry Birk, D Can J Earth Sel V27, N2, Feb 1990, P163-179 Laboratory examination of coals from the Sydney Coalfield has enabled mineral particles to be detected and their chemical classes and size distribution to be quantified. Manual techniques were used to augment computer-automated scans. Details of seam mineralogy are presented and potential applications of this information discussed.
9O6O32 Tension apparatus for monitoring weight loss from a single core. Note Rodd, A V; Webster, D H Can J Soil Sci V70, N1, Feb 1990, P105-107 Water retention characteristics of soils are usually measured using the tension table/pressure plate apparatus. A technique to conveniently determine when equilibrium has been reached is described. The tension cup is supported on a top loading electronic balance which is linked to a monitoring computer. Equilibrium is considered to be reached when there is no net weight loss over a 4 hour period. Equilibrium times determined in this manner are much shorter than 'standard' specified equilibrium times.
906033 Characteristics of joints and faults Gabrielsen, R H Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 Pl1-17. Publ Rotterdam: A A Balkema, 1990 Complete characterization of a naturally fractured rock body requires knowledge of fracture frequency, geometry and spatial configuration, fill materials, deformational style, sense of displacement, and relative ages of the fracture systems. The various fracture geometries are illustrated. The most common is single fracture surfaces. Deformation bands and shear bands are made up of swarms of single fractures, and may be intermediate in the formation of large faults. Deformational response of rock subject to increasing stress field is discussed.
906034 Identification and characterisation of sets of fractures and faults in rock Bridges, M C Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P19-26. Publ Rotterdam: A A Balkema, 1990 A new technique is presented to identify natural sets of fractures in rock, which is more powerful than the traditional approach of relying on orientation densities alone. It involves recognising a pattern of angular relations amongst the fractures, and can identify dominant and minor sets,eccentric shaped sets, and partially overlapping sets. Each fracture can be assigned to identified sets and forms the basis for characterisation of each set. Sensitivity is discussed.
906035 Characteristics of pre- and syn-consolidation structures and tectonic joints and microfaults in fine to medium-grnined sandstones Gabrielsen, R H; Aarland, R K Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P45-50. Publ Rotterdam: A A Balkema, 1990 Fractures of different genesis may have different properties and different influences on the permeability of a naturally fractured reservoir. Three regimes have been identified: pre-consolidation, syn/post-consolidation (including compaction and dewatering fractures), and tectonic. There may be a gradual transition between fractures belonging to these regimes, as compactional fractures may be re-used for water escape and re-activated in later tectonic events. Microstructural features characterising these fracture types are described. 906036 Three dimensional stochastic joint geometry modelling including a verification: a case study Kulatilake, P H S; Wathugala, D N; Stephansson, O Proc International Symposium on Rock Joints, Locn, 4-6 June 1990 P67-74. Publ Rotterdam: A A Balkema, 1990 A realistic representation of joint geometry is necessary for design of engineering projects. The development of a 3D scheme which investigates statistical homogeneity, includes corrections for sampling bias and applications of stereological principles, and has a formal verification procedure is described. Joint data from Stripa mine were used in the investigation. It has been found necessary to try various schemes for modelling joint geometry parameters to achieve good agreement with field data during verification. 906037 Analysis of structural homogeneity of rock mass around ventilation drift Stripa mine Kulatilake, P H S; Wathugala, D N; Stephansson, O Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P75-82. Publ Rotterdam: A ,4 Balkema, 1990 Joint geometry parameters are inherently statistical. The features and ability of the test of Miller (1983) to investigate the structural homogeneity of a rock mass are outlined. Using data from Stripa, the uncertainty of statistical homogeneity which results from use of only Miller's test or equal area polar plots is demonstrated. New interpretations of Miller's analysis are proposed, and used together with equal area polar plots to identify the largest statistically homogeneous regions around the drift. 9O6O38 Characterizing joint spatial correlation using geostatisticai methods Villaescusa, E; Brown, E T Proc International Symposium on Rock Joints, Locn, 4-6 June 1990 P115-122. Publ Rotterdam: A A Balkema, 1990 Rock fabric data from three field sites (ignimhrite, andesite, siliceous and pyritic ores) obtained by detailed line mapping indicate joint locations to be spatially correlated. Degree of spatial correlation was assessed by geostatistical analysis, with variograms of joint spacing with respect to joint sequence number and to distance, and of joint frequency with respect to distance being plotted. Results indicate location of joints within the rock mass is not purely random, with ranges of influence being as large as 40m. More realistic modelling of rock masses is possible if spatial correlation of joints is included.
© 1990 Pergamon Press plc. Reproduction not permitted
Composition, structure texture and density See also: 906018, 906241
906031 Quantitative coal mineralogy of the Sydney Coalfield, Nova Scotia, Canada,by scanning electron microscopy, computerised image analysis, and energy dispersive X-ray spectrometry Birk, D Can J Earth Sel V27, N2, Feb 1990, P163-179 Laboratory examination of coals from the Sydney Coalfield has enabled mineral particles to be detected and their chemical classes and size distribution to be quantified. Manual techniques were used to augment computer-automated scans. Details of seam mineralogy are presented and potential applications of this information discussed.
9O6O32 Tension apparatus for monitoring weight loss from a single core. Note Rodd, A V; Webster, D H Can J Soil Sci V70, N1, Feb 1990, P105-107 Water retention characteristics of soils are usually measured using the tension table/pressure plate apparatus. A technique to conveniently determine when equilibrium has been reached is described. The tension cup is supported on a top loading electronic balance which is linked to a monitoring computer. Equilibrium is considered to be reached when there is no net weight loss over a 4 hour period. Equilibrium times determined in this manner are much shorter than 'standard' specified equilibrium times.
906033 Characteristics of joints and faults Gabrielsen, R H Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 Pl1-17. Publ Rotterdam: A A Balkema, 1990 Complete characterization of a naturally fractured rock body requires knowledge of fracture frequency, geometry and spatial configuration, fill materials, deformational style, sense of displacement, and relative ages of the fracture systems. The various fracture geometries are illustrated. The most common is single fracture surfaces. Deformation bands and shear bands are made up of swarms of single fractures, and may be intermediate in the formation of large faults. Deformational response of rock subject to increasing stress field is discussed.
906034 Identification and characterisation of sets of fractures and faults in rock Bridges, M C Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P19-26. Publ Rotterdam: A A Balkema, 1990 A new technique is presented to identify natural sets of fractures in rock, which is more powerful than the traditional approach of relying on orientation densities alone. It involves recognising a pattern of angular relations amongst the fractures, and can identify dominant and minor sets,eccentric shaped sets, and partially overlapping sets. Each fracture can be assigned to identified sets and forms the basis for characterisation of each set. Sensitivity is discussed.
906035 Characteristics of pre- and syn-consolidation structures and tectonic joints and microfaults in fine to medium-grnined sandstones Gabrielsen, R H; Aarland, R K Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P45-50. Publ Rotterdam: A A Balkema, 1990 Fractures of different genesis may have different properties and different influences on the permeability of a naturally fractured reservoir. Three regimes have been identified: pre-consolidation, syn/post-consolidation (including compaction and dewatering fractures), and tectonic. There may be a gradual transition between fractures belonging to these regimes, as compactional fractures may be re-used for water escape and re-activated in later tectonic events. Microstructural features characterising these fracture types are described. 906036 Three dimensional stochastic joint geometry modelling including a verification: a case study Kulatilake, P H S; Wathugala, D N; Stephansson, O Proc International Symposium on Rock Joints, Locn, 4-6 June 1990 P67-74. Publ Rotterdam: A A Balkema, 1990 A realistic representation of joint geometry is necessary for design of engineering projects. The development of a 3D scheme which investigates statistical homogeneity, includes corrections for sampling bias and applications of stereological principles, and has a formal verification procedure is described. Joint data from Stripa mine were used in the investigation. It has been found necessary to try various schemes for modelling joint geometry parameters to achieve good agreement with field data during verification. 906037 Analysis of structural homogeneity of rock mass around ventilation drift Stripa mine Kulatilake, P H S; Wathugala, D N; Stephansson, O Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P75-82. Publ Rotterdam: A ,4 Balkema, 1990 Joint geometry parameters are inherently statistical. The features and ability of the test of Miller (1983) to investigate the structural homogeneity of a rock mass are outlined. Using data from Stripa, the uncertainty of statistical homogeneity which results from use of only Miller's test or equal area polar plots is demonstrated. New interpretations of Miller's analysis are proposed, and used together with equal area polar plots to identify the largest statistically homogeneous regions around the drift. 9O6O38 Characterizing joint spatial correlation using geostatisticai methods Villaescusa, E; Brown, E T Proc International Symposium on Rock Joints, Locn, 4-6 June 1990 P115-122. Publ Rotterdam: A A Balkema, 1990 Rock fabric data from three field sites (ignimhrite, andesite, siliceous and pyritic ores) obtained by detailed line mapping indicate joint locations to be spatially correlated. Degree of spatial correlation was assessed by geostatistical analysis, with variograms of joint spacing with respect to joint sequence number and to distance, and of joint frequency with respect to distance being plotted. Results indicate location of joints within the rock mass is not purely random, with ranges of influence being as large as 40m. More realistic modelling of rock masses is possible if spatial correlation of joints is included.
© 1990 Pergamon Press plc. Reproduction not permitted