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Quantitative analysis of aggregate shape based on fractals
65A geomechanicai computer codes PHREEQE and EQ3/6, which were used to study stability of pH in presence of or absence of different minerals. Titrations of two dilute acidic solutions into the groundwaters were simulated for cases of mineral equilibria and non-mineral equilibration.
Properties of Rocks and Soils Composition, structure texture and density 942031 Quantitative analysis of aggregate shape based on fraetals Li, L; Chan, P; Zollinger, D G; Lytton, R L ACI Mater J V90, N4, July-Aug 1993, P357-365
A new approach is proposed for quantitative description of aggregate shape and the change in shape associated with different aggregate types using fractals. The method is based on development of a mathematical relation for the boundary of an aggregate, the shape density function. Fractal dimensions are computed using grids of different shapes and sizes. Values for five aggregate shapes, rounded, rectangular, triangular,pentagonal, and elongated, have been determined. 942032 Novel method for the evaluation of particle sharpness Steward, N R; Ruthert, H J S Aft Inst Min Metall V93, NS, May 1993, P121-127
The ability of particulate material to cause damage and wear depends on particle sharpness, hardness, and size. Because of lack of effective methods of determining particle abrasivity, definitions of particle sharpness have tended to be vague. A definition of sharpness is proposed on the basis of the degree to which the perimeter of a particle changes along its length and the rate of each change on that perimeter. A method to compute the sharpness using a microscope, video camera, framegrabber, and image analysis software is presented. 942033 Study of the packing of particles with a mixture size distribution Yu, A B; Standish, N Powder Technol V70, N2, Aug 1993, Pl13-134
The theoretical treatment of packing of particles with a mixture size distribution is first rationalised. The linear-mixture packing model is shown to satisfactorily predict porosity for this packing system. Packing binary and ternary mixtures of lognormal distribution is discussed and results compared to those for packing of particles with a discrete size distribution. Multi-component systems are considered with reference to those found in engineering practice, such as granular backfill. 942034 Microscopic imaging of porous media with X-ray computer tomography Jasti, J K; Jesion, G; Feldkamp, L SPE Form Eval V8, N3, Sept 1993, P189-193
A new method for imaging the 3D structure of porous materials is presented, based on high resolution X-ray computed tomography. A cone shaped divergent beam is used to generate a 2D transmission image and a 3D reconstruction array created directly, rather than assembling a series of 2D slices. Direct measurement of geometric and topological properties on a microscale and imaging the distribution of multiple pore fluids in the void space are possible. Typical results are illustrated.
942035 Proton magnetic resonance and pore size variations in reservoir sandstones Howard, J J; Kenyon, W E; Straley, C SPE Form Eval V8, N3, Sept 1993, P194-200
Proton nuclear magnetic resonance measurements were made on a range of water-saturated sandstones. Longitudinal relaxation time is closely related to pore size distribution. The relatively narrow distribution curve of relaxation times corresponds to the narrow distribution of large pores seen in thin sections. The surface relaxivity which scales relaxation times into pore size is obtained by comparing mean relaxation time for each sample with average pore diameter and volume/surface area data from image analysis of thin sections. Estimated permeabilities using N M R parameters closely approximate measured permeabilities for these samples. 942036 Geometrical model for numerical simulation of capillary imbibition in sedimentary rocks Hammecker, C; Mertz, J D; Fischer, C; Jeannette, D Trans Porous Media V12, N2, Aug 1993, P125-141
The cylindrical element model of porous bodies is discussed and a new tube model proposed to describe the capillary imbibition kinetics of porous sedimentary rocks. The tube model consists of a periodic succession of single hollow spherical elements, with geometry defined by sphere radius and sphere access radius. These two parameters have been evaluated experimentally for limestone and sandstone rocks from their specific surface area. A direct relation between specific surface area and capillary imbibition kinetics can be derived, hence either may be estimated from knowledge of the other. 942037 Characterization of joint patterns from trace maps Cravero, M; Iabichino, G Proc EUROCK'93, Lisbon, 21-24 June 1993 V1, P53-61. Publ Rotterdam: A A Balkema, 1993
Statistical description of geomechanical parameters ofjointing from analysis of trace maps from 2 rock faces in Jurassic limestone and synthetic data is presented. Joint orientation, joint size, trace length, and joint spacing were analysed. The implication of modelling assumptions on simulated trace planes is pointed out. 942038 Geometric conceptual models for fractured rock masses: implications for groundwater flow and rock deformation Dershowitz, W S Proc EUROCK'93, Lisbon, 21-24 June 1993 VI, P71-81. Publ Rotterdam: A A Balkema, 1993
Recent progress in development of conceptual models of fracture systems is described. Fracture geometry, fracture shape, fracture location, fracture size, planarity, and roughness are considered. Field and numerical modelling results are presented which demonstrate the importance of accurate represcntation of the spatial structure of fracturing. 942039 Application of scan-line techniques for fracture analysis in marble quarries de Gama, C D; Afonso, J C A Proc EUROCK'93, Lisbon, 21-24 June 1993 VI, P121-127. Publ Rotterdam: A A Balkema, 1993
Block size and quality, extraction method and equipment, and economics of dimension stone quarrying are all influenced by the natural fracture pattern of the rock. The use of systematic
Properties of Rocks and Soils Composition, structure texture and density 942031 Quantitative analysis of aggregate shape based on fraetals Li, L; Chan, P; Zollinger, D G; Lytton, R L ACI Mater J V90, N4, July-Aug 1993, P357-365
A new approach is proposed for quantitative description of aggregate shape and the change in shape associated with different aggregate types using fractals. The method is based on development of a mathematical relation for the boundary of an aggregate, the shape density function. Fractal dimensions are computed using grids of different shapes and sizes. Values for five aggregate shapes, rounded, rectangular, triangular,pentagonal, and elongated, have been determined. 942032 Novel method for the evaluation of particle sharpness Steward, N R; Ruthert, H J S Aft Inst Min Metall V93, NS, May 1993, P121-127
The ability of particulate material to cause damage and wear depends on particle sharpness, hardness, and size. Because of lack of effective methods of determining particle abrasivity, definitions of particle sharpness have tended to be vague. A definition of sharpness is proposed on the basis of the degree to which the perimeter of a particle changes along its length and the rate of each change on that perimeter. A method to compute the sharpness using a microscope, video camera, framegrabber, and image analysis software is presented. 942033 Study of the packing of particles with a mixture size distribution Yu, A B; Standish, N Powder Technol V70, N2, Aug 1993, Pl13-134
The theoretical treatment of packing of particles with a mixture size distribution is first rationalised. The linear-mixture packing model is shown to satisfactorily predict porosity for this packing system. Packing binary and ternary mixtures of lognormal distribution is discussed and results compared to those for packing of particles with a discrete size distribution. Multi-component systems are considered with reference to those found in engineering practice, such as granular backfill. 942034 Microscopic imaging of porous media with X-ray computer tomography Jasti, J K; Jesion, G; Feldkamp, L SPE Form Eval V8, N3, Sept 1993, P189-193
A new method for imaging the 3D structure of porous materials is presented, based on high resolution X-ray computed tomography. A cone shaped divergent beam is used to generate a 2D transmission image and a 3D reconstruction array created directly, rather than assembling a series of 2D slices. Direct measurement of geometric and topological properties on a microscale and imaging the distribution of multiple pore fluids in the void space are possible. Typical results are illustrated.
942035 Proton magnetic resonance and pore size variations in reservoir sandstones Howard, J J; Kenyon, W E; Straley, C SPE Form Eval V8, N3, Sept 1993, P194-200
Proton nuclear magnetic resonance measurements were made on a range of water-saturated sandstones. Longitudinal relaxation time is closely related to pore size distribution. The relatively narrow distribution curve of relaxation times corresponds to the narrow distribution of large pores seen in thin sections. The surface relaxivity which scales relaxation times into pore size is obtained by comparing mean relaxation time for each sample with average pore diameter and volume/surface area data from image analysis of thin sections. Estimated permeabilities using N M R parameters closely approximate measured permeabilities for these samples. 942036 Geometrical model for numerical simulation of capillary imbibition in sedimentary rocks Hammecker, C; Mertz, J D; Fischer, C; Jeannette, D Trans Porous Media V12, N2, Aug 1993, P125-141
The cylindrical element model of porous bodies is discussed and a new tube model proposed to describe the capillary imbibition kinetics of porous sedimentary rocks. The tube model consists of a periodic succession of single hollow spherical elements, with geometry defined by sphere radius and sphere access radius. These two parameters have been evaluated experimentally for limestone and sandstone rocks from their specific surface area. A direct relation between specific surface area and capillary imbibition kinetics can be derived, hence either may be estimated from knowledge of the other. 942037 Characterization of joint patterns from trace maps Cravero, M; Iabichino, G Proc EUROCK'93, Lisbon, 21-24 June 1993 V1, P53-61. Publ Rotterdam: A A Balkema, 1993
Statistical description of geomechanical parameters ofjointing from analysis of trace maps from 2 rock faces in Jurassic limestone and synthetic data is presented. Joint orientation, joint size, trace length, and joint spacing were analysed. The implication of modelling assumptions on simulated trace planes is pointed out. 942038 Geometric conceptual models for fractured rock masses: implications for groundwater flow and rock deformation Dershowitz, W S Proc EUROCK'93, Lisbon, 21-24 June 1993 VI, P71-81. Publ Rotterdam: A A Balkema, 1993
Recent progress in development of conceptual models of fracture systems is described. Fracture geometry, fracture shape, fracture location, fracture size, planarity, and roughness are considered. Field and numerical modelling results are presented which demonstrate the importance of accurate represcntation of the spatial structure of fracturing. 942039 Application of scan-line techniques for fracture analysis in marble quarries de Gama, C D; Afonso, J C A Proc EUROCK'93, Lisbon, 21-24 June 1993 VI, P121-127. Publ Rotterdam: A A Balkema, 1993
Block size and quality, extraction method and equipment, and economics of dimension stone quarrying are all influenced by the natural fracture pattern of the rock. The use of systematic