- Email: [email protected]
Evaluation of methods for determining the vertical distribution of hydraulic conductivity
209A 904O96 Laboratory and in situ rock thermal property measurements in hot mine lnnaurato. N; OcceUa. E Proc International Symposium on Rock at Great Depth, Pau, 28-31 August 1989 VI, P379-385. Publ Rotterdam: A A Balkema, 1989
porous rock matrix will lead to nonuniform downward flux. Where pore pressures within the matrix are positive, flow may be diverted into adjacent fractures. The study forms a basis for designing hydrogeological property and recharge distribution testing programs compatible with design models that can characterise downward flux.
The Campiano mine in Tuscany shows anomalously high temperatures. Large scale field tests have examined the thermal properties of inhomogenous, fractured, porous rocks, some with fluid inclusions. Diffusivity and surface heat transfer coefficient were determined for clay shales, phyilites and pyrite. These rocks, evaporite, anhydrite and breccia were also examined on a laboratory scale. Comparative analysis is made between field and laboratory values. Some correlations are attempted between thermal characteristics and physical and textural features of the rocks.
904100 Solutions of a steady state free surface seepage problem on a Hypercuhe concurrent computer Wang, K P; Bruch, J C Engng Comput V6, N3, Sept 1989. P225-236
904097 Use of well log data for predicting detailed in situ thermal conductivity profiles at well sites and estimation of lateral changes in main sedimentary units at basin scale Brigaud, F; Vasseur, G; Caillet, G Proc International Symposium on Rock at Great Depth, Pau, 28-31 August 1989 VI, P403-409. Publ Rotterdam: A A Balkema. 1989 Thermal conductivity of sedimentary rock is an important parameter in basin modelling as it directly controls vertical temperature distribution. As core samples are rare from exploration boreholes, conductivity must be evaluated from routinely recorded data such as well logs. The thermal conductivity model is discussed on the basis of laboratory measurement. Well logs are interpreted in terms of lithology and porosity, mineralogy varying with stratigraphy of each lithologic unit is assumed, and a procedure for calculating in situ thermal conductivity profiles is presented. Application to wells in the Viking graben in the North Sea is illustrated. 904098 Finite element analysis of coupled thermoelasticity Carter, J P; Booker, J R Un&ersity of Sydney, School of Civil and Mining Engineering, Research Report N599. May 1989, 30P A fully coupled approach to the problem of thermoelasticity in geological materials is presented. The governing equations are presented and a finite element solution scheme (AFENA) is suggested. The accuracy of the numerical scheme is assessed by its application to problems for which analytical solutions are available. A parametric study of these problems is carried out to examine when fully coupling the thermal and elastic processes is important. Results are obtained for problems of heat flow into a square tunnel on cooling of its surfaces and storage of radioactive waste in a borehole.
Permeability and capillarity 904099 Distribution of downward flux in unsaturated heterogeneous hydrogeology environments Bloomsburg, G; Williams, R E; Osiensky, J L Bull Geol Soc Am VIOl, NI2, Dec 1989, P!623-1630 The finite element program UNSAT2 was used to quantify horizontal distribution of unsaturated downward flux in porous tuff at the proposed repository site at Yucca Mountain, Nevada, as a function of hydraulic inhomogeneities at two recharge rates. Results show heterogeneity in an isotropic
© RMMS 27 4--H
Flows through porous media, in particular those with a free surface, are of great interest to the geotechnical engineer. The computational task involves the solution of a large set of linear equations with a projection operation numerous times. The case of steady, two dimensional seepage through a slanted, curved face dam with a toe drain is considered. Solutions using both Jacobi and SOR iterations are obtained quickly and efficiently using a parallel processing system. Comparisons are made with solution times for single CPU systems. 904101 Note on falling headwater and rising tailwater permeability tests. Technical note Daniel, D E Geotech Test J VI2, N4, Dec 1989, P308-310 Falling head permeability tests may be performed with constant or rising tailwater pressure. Equations generally quoted for determination of permeability using the falling head test are only valid in the former case, and an error factor of 2 is induced if they are used in the rising tailwater case. Correct equations for use in both cases are derived and presented. 904102 Laboratory and numerical investigation of solute transport in discontinuous fracture systems Robinson, J W; Gale, J E Ground Water V28, NI, Jan-Feb 1990. P25-36 Mixing of fluids at fracture intersections was studied using plexiglass models and a two dimensional, finite element discrete fracture model. Physical models with two continuous fully intersecting fractures, a single continuous fracture offsetting a second fracture, and parallel fractures in two intersecting sets were used. No mixing occurred at fully intersecting fractures with equal apertures. Mixing was dependent on relative size of inlet and outlet even with multiple intersections. The mixing algorithm from model tests was used in the finite element code EXPORT. Predictions suggest more longitudinal and less lateral dispersion take place than when complete mixing at fracture intersections is assumed. Contaminants will not be diluted to the extent previous models have predicted. 9041O3 Evaluation of methods for determining the vertical distribution of hydraulic conductivity Taylor, K; Wheatcraft, S; Hess, J; Hayworth, J; Molz, F Ground Water V28. NI, Jan-Feb 1990, P88-98 Six methods have been critically examined. Straddle packer tests are invalid if flow paths exist around the packer on the outside of the well screen. Particle size analysis methods are inaccurate due to sampling problems and small-scale microstructural effects. Empirical electrical-hydraulic conductivity relations are site and formation specific. Stonely wave attenuation methods are invalid in unconsolidated formations. Borehole effects invalidate methods based on natural flow through
1990 Pergamon Press plc. Reproduction not permitted
210A a borehole. Single well electrical tracer tests are effective, but require monitoring of the injection of significant volumes of fluid into the formation.
904104 Analysis of aquifer tests conducted in fractured rock: a review of the physical background and the design of a computer program for generating type curves. Computer note Novakowski, K S Ground Water 1/28, NI, Jan-Feb 1990, P99-107 Analysis of hydrological characteristics of fractured rocks between wells can be undertaken by traditional pumping tests or by pulse interference tests. A F O R T R A N program has been developed to generate type curves for these tests which takes into account wellbore storage, wellbore skin effects, and the heterogeneity of the rock mass. It will generate single type curves on a PC in only a few minutes.
904105 Turbulent seepage flow through rockfill structures Martins. R Int Water Power Dam Constr V42, N3. March 1990, P41-45 Rockfill is widely used in hydraulic engineering. Mean seepage velocity is one of the parameters required to predict hydraulic conditions in rockfill structures such as cofferdams, weirs, and filters. Mean seepage flow velocity was determined in the laboratory under turbulent conditions (Reynold's number above 300) for a variety of uniform angular (crushed), uniform rounded (gravel), and non-uniform angular particles. A parameter which allows estimation of seepage velocity at lower Reynold's number is given.
904106 Filtration of broadly graded cohesionless soils Lafleur, J; Mlynarek, J; Rollin, A L J Geotech Engng Div ASCE VlI5, NI2, Dec 1989. P17471768 Filter criteria of soils are relevant to piping erosion. The filtration process of a broady graded soil is essentially different to that of uniform soil, and the same filter criteria do not apply to both. Laboratory tests on graded soils have examined selffiltration at the base-filter interface. Potential migration of base materials, the self filtration layer, and particles carried away have been quantified. The last two properties are related to gradation curve profiles and soil broadness coefficient. Representative grain size of the base material promoting the self filtration process was also examined.
904107 Influence of pore distribution on the hydraulic conductivity of some Swedish tills Lind, B B J Hydroi VII2, NI/2, Dec 1989. P41-53 Relations between pore size distribution and hydraulic conductivity were studied on 42 undisturbed samples. Conductivity was randomly related to total porosity. There was a significant correlation between hydraulic conductivity and pore volume in the 35-90 micron interval, but no similar relation for coarser pores. It is suggested that this is because a continuous network of microfissui'es, 50-100 microns wide, is found in the till, but larger pores tend to be isolated.
904108 Hydrologic responses of compacted forest soils Gardner, B D" Chong. S K J Hydrol VII2. N3 4. Jan 1990. P327-334 Compaction due to machinery is a recent phenomenon for field soils. Samples of a fine silty soil were taken and compacted at pressures 45-315kPa after wetting to 10, 15, and 20% water content by weight. Sorptivity, effective hydraulic conductivity and Boltzmann's constant were measured and related to bulk density and degree of saturation. Unexpectedly low sorptivity and hydraulic conductivity were seen at low water content. Cores with low water content and bulk density had relatively low sorptivity, indicating water unfillable porosity, attributed to entrapped air. Consequences to runoff on field-compacted soils are examined. 904109 Fractal methods improve Mitsue miscible predictions Mathews, J L; Emanuel, A S: Edwards, K A J Pet Technol V41. Nil, Nor 1989, Pl136-I142 Reservoir modelling, whereby a representative geological cross section between injection and producing wells is created using log and core details and fractal geostatistics, is described. Response to a miscible hydrocarbon water-alternating-gas (WAG) flood is modelled using a hybrid finite difference/streamflow approach. The technique is efficient in terms of both output and computer time. Predictions are close to field observations, and a considerable improvement over coarse-grid simulation models. 904110 Numerical model of contaminant transport through conduitporous matrix system Bobba, A G Math Geol V21, N8, Oct 1989, P861-890 A mathematical model is derived for contaminant transport within a cylindrically symmetrical conduit-porous matrix system. Convection and diffusion are considered in the conduit, diffusion only in the matrix. The two subsystems are coupled using continuity conditions imposed at their interface. Transport solutions are solved by the alternating-direct-implicitmethod (ADIM). Solute concentration profiles are illustrated and discussed. 904111 Multiphase flow and transport in porous media Parker, J C Rev Geophys V27, N3. Aug 1989, P311-328 Principles of modelling flow in systems containing up to 3 fluid pahses (air, water, organic) are outlined. Knowledge is required of functional relations between fluid pressures, saturation, and permeabilities, which may be formulated on the basis of conceptual models of fluid-porous medium reactions. Hypothetical numerical problems are presented to illustrate applications. 904112 Multiscale study of the permeability of a thick clayey till Keller, C K: van der Kamp, G: Cherry, J A Water Resour Res V23, N i l , Nor 1989, P2299-2317 Low permeability clay layers can control groundwater flow in many situations. Bulk values of K on scales from hundreds to thousands of metres are required for management purposes. Measurement at this scale is usually costly and time consuming. Two new methods of evaluating bulk permeability are
~-' 1990 Pergamon Press pie. Reproduction not permitted
porous rock matrix will lead to nonuniform downward flux. Where pore pressures within the matrix are positive, flow may be diverted into adjacent fractures. The study forms a basis for designing hydrogeological property and recharge distribution testing programs compatible with design models that can characterise downward flux.
The Campiano mine in Tuscany shows anomalously high temperatures. Large scale field tests have examined the thermal properties of inhomogenous, fractured, porous rocks, some with fluid inclusions. Diffusivity and surface heat transfer coefficient were determined for clay shales, phyilites and pyrite. These rocks, evaporite, anhydrite and breccia were also examined on a laboratory scale. Comparative analysis is made between field and laboratory values. Some correlations are attempted between thermal characteristics and physical and textural features of the rocks.
904100 Solutions of a steady state free surface seepage problem on a Hypercuhe concurrent computer Wang, K P; Bruch, J C Engng Comput V6, N3, Sept 1989. P225-236
904097 Use of well log data for predicting detailed in situ thermal conductivity profiles at well sites and estimation of lateral changes in main sedimentary units at basin scale Brigaud, F; Vasseur, G; Caillet, G Proc International Symposium on Rock at Great Depth, Pau, 28-31 August 1989 VI, P403-409. Publ Rotterdam: A A Balkema. 1989 Thermal conductivity of sedimentary rock is an important parameter in basin modelling as it directly controls vertical temperature distribution. As core samples are rare from exploration boreholes, conductivity must be evaluated from routinely recorded data such as well logs. The thermal conductivity model is discussed on the basis of laboratory measurement. Well logs are interpreted in terms of lithology and porosity, mineralogy varying with stratigraphy of each lithologic unit is assumed, and a procedure for calculating in situ thermal conductivity profiles is presented. Application to wells in the Viking graben in the North Sea is illustrated. 904098 Finite element analysis of coupled thermoelasticity Carter, J P; Booker, J R Un&ersity of Sydney, School of Civil and Mining Engineering, Research Report N599. May 1989, 30P A fully coupled approach to the problem of thermoelasticity in geological materials is presented. The governing equations are presented and a finite element solution scheme (AFENA) is suggested. The accuracy of the numerical scheme is assessed by its application to problems for which analytical solutions are available. A parametric study of these problems is carried out to examine when fully coupling the thermal and elastic processes is important. Results are obtained for problems of heat flow into a square tunnel on cooling of its surfaces and storage of radioactive waste in a borehole.
Permeability and capillarity 904099 Distribution of downward flux in unsaturated heterogeneous hydrogeology environments Bloomsburg, G; Williams, R E; Osiensky, J L Bull Geol Soc Am VIOl, NI2, Dec 1989, P!623-1630 The finite element program UNSAT2 was used to quantify horizontal distribution of unsaturated downward flux in porous tuff at the proposed repository site at Yucca Mountain, Nevada, as a function of hydraulic inhomogeneities at two recharge rates. Results show heterogeneity in an isotropic
© RMMS 27 4--H
Flows through porous media, in particular those with a free surface, are of great interest to the geotechnical engineer. The computational task involves the solution of a large set of linear equations with a projection operation numerous times. The case of steady, two dimensional seepage through a slanted, curved face dam with a toe drain is considered. Solutions using both Jacobi and SOR iterations are obtained quickly and efficiently using a parallel processing system. Comparisons are made with solution times for single CPU systems. 904101 Note on falling headwater and rising tailwater permeability tests. Technical note Daniel, D E Geotech Test J VI2, N4, Dec 1989, P308-310 Falling head permeability tests may be performed with constant or rising tailwater pressure. Equations generally quoted for determination of permeability using the falling head test are only valid in the former case, and an error factor of 2 is induced if they are used in the rising tailwater case. Correct equations for use in both cases are derived and presented. 904102 Laboratory and numerical investigation of solute transport in discontinuous fracture systems Robinson, J W; Gale, J E Ground Water V28, NI, Jan-Feb 1990. P25-36 Mixing of fluids at fracture intersections was studied using plexiglass models and a two dimensional, finite element discrete fracture model. Physical models with two continuous fully intersecting fractures, a single continuous fracture offsetting a second fracture, and parallel fractures in two intersecting sets were used. No mixing occurred at fully intersecting fractures with equal apertures. Mixing was dependent on relative size of inlet and outlet even with multiple intersections. The mixing algorithm from model tests was used in the finite element code EXPORT. Predictions suggest more longitudinal and less lateral dispersion take place than when complete mixing at fracture intersections is assumed. Contaminants will not be diluted to the extent previous models have predicted. 9041O3 Evaluation of methods for determining the vertical distribution of hydraulic conductivity Taylor, K; Wheatcraft, S; Hess, J; Hayworth, J; Molz, F Ground Water V28. NI, Jan-Feb 1990, P88-98 Six methods have been critically examined. Straddle packer tests are invalid if flow paths exist around the packer on the outside of the well screen. Particle size analysis methods are inaccurate due to sampling problems and small-scale microstructural effects. Empirical electrical-hydraulic conductivity relations are site and formation specific. Stonely wave attenuation methods are invalid in unconsolidated formations. Borehole effects invalidate methods based on natural flow through
1990 Pergamon Press plc. Reproduction not permitted
210A a borehole. Single well electrical tracer tests are effective, but require monitoring of the injection of significant volumes of fluid into the formation.
904104 Analysis of aquifer tests conducted in fractured rock: a review of the physical background and the design of a computer program for generating type curves. Computer note Novakowski, K S Ground Water 1/28, NI, Jan-Feb 1990, P99-107 Analysis of hydrological characteristics of fractured rocks between wells can be undertaken by traditional pumping tests or by pulse interference tests. A F O R T R A N program has been developed to generate type curves for these tests which takes into account wellbore storage, wellbore skin effects, and the heterogeneity of the rock mass. It will generate single type curves on a PC in only a few minutes.
904105 Turbulent seepage flow through rockfill structures Martins. R Int Water Power Dam Constr V42, N3. March 1990, P41-45 Rockfill is widely used in hydraulic engineering. Mean seepage velocity is one of the parameters required to predict hydraulic conditions in rockfill structures such as cofferdams, weirs, and filters. Mean seepage flow velocity was determined in the laboratory under turbulent conditions (Reynold's number above 300) for a variety of uniform angular (crushed), uniform rounded (gravel), and non-uniform angular particles. A parameter which allows estimation of seepage velocity at lower Reynold's number is given.
904106 Filtration of broadly graded cohesionless soils Lafleur, J; Mlynarek, J; Rollin, A L J Geotech Engng Div ASCE VlI5, NI2, Dec 1989. P17471768 Filter criteria of soils are relevant to piping erosion. The filtration process of a broady graded soil is essentially different to that of uniform soil, and the same filter criteria do not apply to both. Laboratory tests on graded soils have examined selffiltration at the base-filter interface. Potential migration of base materials, the self filtration layer, and particles carried away have been quantified. The last two properties are related to gradation curve profiles and soil broadness coefficient. Representative grain size of the base material promoting the self filtration process was also examined.
904107 Influence of pore distribution on the hydraulic conductivity of some Swedish tills Lind, B B J Hydroi VII2, NI/2, Dec 1989. P41-53 Relations between pore size distribution and hydraulic conductivity were studied on 42 undisturbed samples. Conductivity was randomly related to total porosity. There was a significant correlation between hydraulic conductivity and pore volume in the 35-90 micron interval, but no similar relation for coarser pores. It is suggested that this is because a continuous network of microfissui'es, 50-100 microns wide, is found in the till, but larger pores tend to be isolated.
904108 Hydrologic responses of compacted forest soils Gardner, B D" Chong. S K J Hydrol VII2. N3 4. Jan 1990. P327-334 Compaction due to machinery is a recent phenomenon for field soils. Samples of a fine silty soil were taken and compacted at pressures 45-315kPa after wetting to 10, 15, and 20% water content by weight. Sorptivity, effective hydraulic conductivity and Boltzmann's constant were measured and related to bulk density and degree of saturation. Unexpectedly low sorptivity and hydraulic conductivity were seen at low water content. Cores with low water content and bulk density had relatively low sorptivity, indicating water unfillable porosity, attributed to entrapped air. Consequences to runoff on field-compacted soils are examined. 904109 Fractal methods improve Mitsue miscible predictions Mathews, J L; Emanuel, A S: Edwards, K A J Pet Technol V41. Nil, Nor 1989, Pl136-I142 Reservoir modelling, whereby a representative geological cross section between injection and producing wells is created using log and core details and fractal geostatistics, is described. Response to a miscible hydrocarbon water-alternating-gas (WAG) flood is modelled using a hybrid finite difference/streamflow approach. The technique is efficient in terms of both output and computer time. Predictions are close to field observations, and a considerable improvement over coarse-grid simulation models. 904110 Numerical model of contaminant transport through conduitporous matrix system Bobba, A G Math Geol V21, N8, Oct 1989, P861-890 A mathematical model is derived for contaminant transport within a cylindrically symmetrical conduit-porous matrix system. Convection and diffusion are considered in the conduit, diffusion only in the matrix. The two subsystems are coupled using continuity conditions imposed at their interface. Transport solutions are solved by the alternating-direct-implicitmethod (ADIM). Solute concentration profiles are illustrated and discussed. 904111 Multiphase flow and transport in porous media Parker, J C Rev Geophys V27, N3. Aug 1989, P311-328 Principles of modelling flow in systems containing up to 3 fluid pahses (air, water, organic) are outlined. Knowledge is required of functional relations between fluid pressures, saturation, and permeabilities, which may be formulated on the basis of conceptual models of fluid-porous medium reactions. Hypothetical numerical problems are presented to illustrate applications. 904112 Multiscale study of the permeability of a thick clayey till Keller, C K: van der Kamp, G: Cherry, J A Water Resour Res V23, N i l , Nor 1989, P2299-2317 Low permeability clay layers can control groundwater flow in many situations. Bulk values of K on scales from hundreds to thousands of metres are required for management purposes. Measurement at this scale is usually costly and time consuming. Two new methods of evaluating bulk permeability are
~-' 1990 Pergamon Press pie. Reproduction not permitted