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Hydraulic characterization of jointed rock using the ‘Pulsation test’
149A 913158 Absorption of water into porous blocks of various shapes and sizes Zimmerman, R W; Bodvarsson, G S Water Resour Res V26, N i l . Not" 1990, P2797-2806
913162 Laboratory studies of transport within a single rock fracture Piggott, A R; Elseworth, D Proc International Symposium on Rock Joints, Locn, 4-6 June 1990 P397-404. Publ Rotterdam: d A Balkema, 1990
Approximate solutions are obtained for absorption of water into porous spherical, cylindrical, and slablike blocks, whose characteristic curves are of the van Genuchten-Mualem type. Solutions are compared to numerical simulations of absorbtion into blocks of Paintbrush tuff from the proposed Yucca Mountain repository site. A scaling law, based on ratio of surface area to volume, is proposed for predicting absorption into irregularly shaped blocks. This law is tested against a numerical simulation of absorption into an irregularly shaped 2-dimensional polygonal block.
Laboratory flow and tracer tests on a 190ram diameter, 320mm long granite core containing a single diametral fracture orientated along the core axis are described. An array of 20 5mm diameter holes was drilled to allow measurement and monitoring of flow behaviour. Pneumatic, hydrologic,and electrical conductivities of the fracture and its solute transport properties were studied under mated and sheared conditions. Distributions of measured parameters and their variation with fracture deformation are discussed.
913159 Diffusion in the matrix of granitic rock: field test in the Stripa Mine Birgersson. L; Neretnieks, I Water Resour Res 1/26, N i l , Nov 1990, P2833-2842
Three field experiments at depth 360m are described. Boreholes were drilled and injection of tracers continued for 3, 6, and 42 months. Cores were taken at various distances from the holes for analysis. Tracers migrated through the disturbed zone close to the wall and then into the undisturbed rock matrix. Results demonstrate the possibility of dissolved compounds migrating into the rock matrix under natural stress conditions. Diffusivities and hydraulic conductivities obtained agree well with those from laboratory experiments. 913160 Development of a model to predict Iongwall gas emissions resulting from overburden failure Trevits, M A; Garcia, F; McCall, F E Rock Mechanics Contributions and Challenges: Proc 31st US Symposium, Golden, 18-20 June 1990 P187-194. Publ Rotterdam: A A Balkema, 1990
Longwall mining operators traditionally used gob gas boreholes to drain methane because they cause minimum disruption and give immediate effects. A preliminary model to predict gas emission has been developed. It considers gas from the mine face and boreholes, mined coal during transport, and roof and floor strata. It is based on European practice. It requires a minimum of input information and can easily be adapted to local conditions. Comparison of model prediction with field experience is shown. 913161 Hydraulic characterization of jointed rock using the 'Pulsation test' Kojima. K; Tosaka, H; Otsuka, Y; ltoh, K; Kondoh, T Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P391-396. Publ Rotterdam: A A Balkema, 1990
Spatial distribution of permeability and permeability and continuity of flow paths are important hydraulic parameters of discontinuous rocks. The Pulsation test, a cross-hole inference technique, can be used to obtain data to characterise spatial distribution of permeability. Pressure buildup and leakoff caused by cyclic injection/shut in are measured at multiple points in multiple boreholes. An inversion technique is used in data processing. Test simulation and field application are described.
913163 Fluid flow through single fractures Pyrak-Nolte, L J; Nolte, D D; Myer, L R; Cook, N G W Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P405-412. Publ Rotterdam: A A Balkema. 1990
A stratified continuum percolation model, which reproduces experimentally observed flow geometry, has been used to investigate saturated and unsaturated flow in a fracture, the change in fluid flow with stress, and the scaling behaviour for saturated flow. Deviation from the cube law behaviour results from the nonlinear relation between apparent mechanical aperture closure (from far field displacement measurements) and void aperture closure. Dependence of flow on sample size is examined using renormalization group techniques. 913164 Parameter study of the influence of aperture variation on fracture flow and the consequences in a fracture network Stratford, R G; Herbert, A W; Jackson, C P Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P413-422. Publ Rotterdam: A A Balkema, 1990 Flow in fractured hard rocks occurs primarily through a connected network of discrete fractures. Aperture distribution over a fracture plane cannot be measured and is usually inferred on the basis of results of borehole tests. Two proposals are examined: that such measurements describe the local aperture variation on individual fractures; and that each fracture may be characterised by a single transmissivity value and field measurements represent samples of the fracture transmissivity distribution. A finite element scheme is developed to generate a correlated field of apertures on a single fracture, and the extent to which this model can simulate field measurements and qualitative observations of channelling in granite is investigated. 913165 Hydrological characterization of variable-aperture fractures Tsang, Y W; Tsang, C F Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P423-431. Publ Rotterdam: A A Balkema, 1990
A statistical description of a fracture with variable aperture is developed using three parameters: mean aperture, standard deviation, and correlate length. Numerical simulation of fracture flow is used to correlate these parameters with measureable hydrological properties. Methods are suggested to determine the basic parameters from flow measurements and tracer breakthrough curves. These methods are currently being evaluated using field and laboratory data.
1991 Pergamon Press plc. Reproduction not permitted
913162 Laboratory studies of transport within a single rock fracture Piggott, A R; Elseworth, D Proc International Symposium on Rock Joints, Locn, 4-6 June 1990 P397-404. Publ Rotterdam: d A Balkema, 1990
Approximate solutions are obtained for absorption of water into porous spherical, cylindrical, and slablike blocks, whose characteristic curves are of the van Genuchten-Mualem type. Solutions are compared to numerical simulations of absorbtion into blocks of Paintbrush tuff from the proposed Yucca Mountain repository site. A scaling law, based on ratio of surface area to volume, is proposed for predicting absorption into irregularly shaped blocks. This law is tested against a numerical simulation of absorption into an irregularly shaped 2-dimensional polygonal block.
Laboratory flow and tracer tests on a 190ram diameter, 320mm long granite core containing a single diametral fracture orientated along the core axis are described. An array of 20 5mm diameter holes was drilled to allow measurement and monitoring of flow behaviour. Pneumatic, hydrologic,and electrical conductivities of the fracture and its solute transport properties were studied under mated and sheared conditions. Distributions of measured parameters and their variation with fracture deformation are discussed.
913159 Diffusion in the matrix of granitic rock: field test in the Stripa Mine Birgersson. L; Neretnieks, I Water Resour Res 1/26, N i l , Nov 1990, P2833-2842
Three field experiments at depth 360m are described. Boreholes were drilled and injection of tracers continued for 3, 6, and 42 months. Cores were taken at various distances from the holes for analysis. Tracers migrated through the disturbed zone close to the wall and then into the undisturbed rock matrix. Results demonstrate the possibility of dissolved compounds migrating into the rock matrix under natural stress conditions. Diffusivities and hydraulic conductivities obtained agree well with those from laboratory experiments. 913160 Development of a model to predict Iongwall gas emissions resulting from overburden failure Trevits, M A; Garcia, F; McCall, F E Rock Mechanics Contributions and Challenges: Proc 31st US Symposium, Golden, 18-20 June 1990 P187-194. Publ Rotterdam: A A Balkema, 1990
Longwall mining operators traditionally used gob gas boreholes to drain methane because they cause minimum disruption and give immediate effects. A preliminary model to predict gas emission has been developed. It considers gas from the mine face and boreholes, mined coal during transport, and roof and floor strata. It is based on European practice. It requires a minimum of input information and can easily be adapted to local conditions. Comparison of model prediction with field experience is shown. 913161 Hydraulic characterization of jointed rock using the 'Pulsation test' Kojima. K; Tosaka, H; Otsuka, Y; ltoh, K; Kondoh, T Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P391-396. Publ Rotterdam: A A Balkema, 1990
Spatial distribution of permeability and permeability and continuity of flow paths are important hydraulic parameters of discontinuous rocks. The Pulsation test, a cross-hole inference technique, can be used to obtain data to characterise spatial distribution of permeability. Pressure buildup and leakoff caused by cyclic injection/shut in are measured at multiple points in multiple boreholes. An inversion technique is used in data processing. Test simulation and field application are described.
913163 Fluid flow through single fractures Pyrak-Nolte, L J; Nolte, D D; Myer, L R; Cook, N G W Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P405-412. Publ Rotterdam: A A Balkema. 1990
A stratified continuum percolation model, which reproduces experimentally observed flow geometry, has been used to investigate saturated and unsaturated flow in a fracture, the change in fluid flow with stress, and the scaling behaviour for saturated flow. Deviation from the cube law behaviour results from the nonlinear relation between apparent mechanical aperture closure (from far field displacement measurements) and void aperture closure. Dependence of flow on sample size is examined using renormalization group techniques. 913164 Parameter study of the influence of aperture variation on fracture flow and the consequences in a fracture network Stratford, R G; Herbert, A W; Jackson, C P Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P413-422. Publ Rotterdam: A A Balkema, 1990 Flow in fractured hard rocks occurs primarily through a connected network of discrete fractures. Aperture distribution over a fracture plane cannot be measured and is usually inferred on the basis of results of borehole tests. Two proposals are examined: that such measurements describe the local aperture variation on individual fractures; and that each fracture may be characterised by a single transmissivity value and field measurements represent samples of the fracture transmissivity distribution. A finite element scheme is developed to generate a correlated field of apertures on a single fracture, and the extent to which this model can simulate field measurements and qualitative observations of channelling in granite is investigated. 913165 Hydrological characterization of variable-aperture fractures Tsang, Y W; Tsang, C F Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P423-431. Publ Rotterdam: A A Balkema, 1990
A statistical description of a fracture with variable aperture is developed using three parameters: mean aperture, standard deviation, and correlate length. Numerical simulation of fracture flow is used to correlate these parameters with measureable hydrological properties. Methods are suggested to determine the basic parameters from flow measurements and tracer breakthrough curves. These methods are currently being evaluated using field and laboratory data.
1991 Pergamon Press plc. Reproduction not permitted