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Hydraulic conductivity of a recent estuarine silty clay at Bothkennar
88A 932130 Geochemical engineering Schuiling, R D Proc 6th International Congress International Association of Engineering Geology, Amsterdam, 6-10 August 1990, Symposia P159-164. Publ Rotterdam: A A Balkema, 1990
932134 Remarks on the design of clay liners used in lagoons as hydraulic barriers. Note Lcroueil, S; Le Bihan, J P; Bouchard, R Can Geoteeh J V29, N3, June 1992, P512-515
Geochemical engineering, the controlled modification of the properties of geological materials, has only been recently so named, but has been practised for centuries. Examples are described: improvement of strength of soils by grouting or stabilisation and modification of permeability of rocks and soils by cementation, soil additives, hydraulic fracturing, and acidizing and acid fracturing. The most rapidly growing application of this technology is in environmental engineering, to transform, concentrate, dilute, isolate, or immobilise contaminants.
Design procedures for clay liners have evolved on an empirical basis. A rational assessment of relevant conditions for the design of clay liners is presented based on the following: hydraulic conductivity of compacted clay is smaller on the wet side of optimum; fissures develop at small stresses if water content is below the plastic limit; plastic limit and optimum standard Proctor content are similar for many natural soils; and strength is a function of difference between water content and optimum Proctor water content divided by plasticity index.
932131 Studies on stability of a simulated borehole in compacted clay Roy, S; Cooper, G A Proc 33rd US Symposium on Rock Mechanics, Santa Fe, 3-5 June 1992 P355-364. Publ Rotterdam: A A Balkema. 1992
932135 Coupled geomechanic-muitiphase flow model for analysis of in situ recovery of cohesionless oil sands Fung, L S K Can Pet Teehnoi V31, N6, June 1992, P56-67
Stabilisation of wellbores in clay-bearing formations is usually attempted by selection of suitable drilling fluids. An alternative has been investigated, in which a potential is applied between a remote electrode and one in the centre of the hole. Its application in pinhole dispersive tests in a compacted sodium bentonite clay is described. When the central electrode was made the cathode, the strongly dispersive clay was stabilised and the effect remained even after the potential was switched off. Surface chemistry responsible for these effects is discussed.
Reservoir operation in oil sands causes fabric disturbance, with changes in pore volume and porosity. These changes depend on the stress state, which is continually altered according to temperature and pressure effects as a result of heat transfer and fluid flow. A numerical model for fully coupled geomechanic-multiphase flow is required to describe reservoir response. The coupled theory for the isothermal situation is presented in detail. The system of nonlinear partial differential equations is discretised using the control volume finite element method (CVFE). The resulting equations are solved using a fully-coupled, fully-implicit approach.
Permeability and capillarity See also: 932020, 932026, 932028, 932029, 932432, 932455 932132 Field investigation of hydraulic conductivity in saproHtic materials - comparison of methods and techniques Welby, C W Bull Assoc Engng Geoi V29, N2, June 1992, Pl19-130
Slug and bailing tests were carried out in shallow wells in saprolite at two sites in the North Carolina Piedmont. Hydraulic conductivities were estimated from test results using McCarthy, Jacob-Theis, Skibitzke, Ferris-Knowles, Hvorslev, and Bouwer-Rice equations. Results are compared and discussed. It is suggested that several calculation methods be applied and ranges of values compared before selecting a single value for application. The geometric mean of a range of values is thought to be best for comparison between methods.
932136 Effect of clod size on hydraulic conductivity of compacted clay Houston, S L; Randeni, J S Geotech Test J V15, N2, June 1992, P123-128 Hydraulic conductivity of compacted clay measured in the field is relatively high compared to laboratory values. Largespecimen laboratory tests in a 195mm diameter permeameter indicate the size and gradation of the clods of clay prior to compaction can have significant influence on measured hydraulic properties. Comparison is made with results of other similar tests and it is concluded that for typical liner materials, the 2 orders of magnitude difference in laboratory and field hydraulic conductivities can be attributed to clod size and gradation effects. Revised laboratory test procedures are proposed to enable data of value for design purposes to be obtained.
932133 Hydraulic conductivity of compacted bentonite-sand mixtures Kenney, T C; van Veen, W A; Swallow, M A; Sungaila, M A Can Geotech d V29, N3, June 1992, P364-374
932137 Hydraulic conductivity of a recent estuarine silty clay at Bothkennar Leroueii, S; Lerat, P; Hight, D W; Powell, J J M Geoteclmique V42, N2, June 1992, P275-288
Bentonite-sand mixtures are widely used in waste barriers. Laboratory tests have been carried out to evaluate effects on hydraulic conductivity of mix content, compaction water content, system chemistry, and change of system chemistry. Continuity of bentonite matrix (adequate bentonite and good mixing) is necessary for low hydraulic conductivity. In wellcompacted mixes with up to 20% bentonite by dry weight, sand provides the load-supporting framework and dimensional stability. The fabric of the bentonite within this framework is little affected when system chemistry is changed from fresh to saline water.
Permeability of the Bothkennar clay has been examined. In situ properties were measured by pushed-in piezometers, selfboring permeameters, and the BAT system. Laboratory measurements used oedometers, triaxial cells, and a radial flow cell. A size effect and an anisotropy ratio, varying with the fabric but generally 1.5-2, are found. Pushed-in piezometers and the BAT system appear to underestimate the hydraulic conductivity. The self-boring permeameter provides the most representative profile. Variation of hydraulic conductivity with compression was quantified.
O 1993 Pergamon Press Ltd. Reproduction not permitted
932134 Remarks on the design of clay liners used in lagoons as hydraulic barriers. Note Lcroueil, S; Le Bihan, J P; Bouchard, R Can Geoteeh J V29, N3, June 1992, P512-515
Geochemical engineering, the controlled modification of the properties of geological materials, has only been recently so named, but has been practised for centuries. Examples are described: improvement of strength of soils by grouting or stabilisation and modification of permeability of rocks and soils by cementation, soil additives, hydraulic fracturing, and acidizing and acid fracturing. The most rapidly growing application of this technology is in environmental engineering, to transform, concentrate, dilute, isolate, or immobilise contaminants.
Design procedures for clay liners have evolved on an empirical basis. A rational assessment of relevant conditions for the design of clay liners is presented based on the following: hydraulic conductivity of compacted clay is smaller on the wet side of optimum; fissures develop at small stresses if water content is below the plastic limit; plastic limit and optimum standard Proctor content are similar for many natural soils; and strength is a function of difference between water content and optimum Proctor water content divided by plasticity index.
932131 Studies on stability of a simulated borehole in compacted clay Roy, S; Cooper, G A Proc 33rd US Symposium on Rock Mechanics, Santa Fe, 3-5 June 1992 P355-364. Publ Rotterdam: A A Balkema. 1992
932135 Coupled geomechanic-muitiphase flow model for analysis of in situ recovery of cohesionless oil sands Fung, L S K Can Pet Teehnoi V31, N6, June 1992, P56-67
Stabilisation of wellbores in clay-bearing formations is usually attempted by selection of suitable drilling fluids. An alternative has been investigated, in which a potential is applied between a remote electrode and one in the centre of the hole. Its application in pinhole dispersive tests in a compacted sodium bentonite clay is described. When the central electrode was made the cathode, the strongly dispersive clay was stabilised and the effect remained even after the potential was switched off. Surface chemistry responsible for these effects is discussed.
Reservoir operation in oil sands causes fabric disturbance, with changes in pore volume and porosity. These changes depend on the stress state, which is continually altered according to temperature and pressure effects as a result of heat transfer and fluid flow. A numerical model for fully coupled geomechanic-multiphase flow is required to describe reservoir response. The coupled theory for the isothermal situation is presented in detail. The system of nonlinear partial differential equations is discretised using the control volume finite element method (CVFE). The resulting equations are solved using a fully-coupled, fully-implicit approach.
Permeability and capillarity See also: 932020, 932026, 932028, 932029, 932432, 932455 932132 Field investigation of hydraulic conductivity in saproHtic materials - comparison of methods and techniques Welby, C W Bull Assoc Engng Geoi V29, N2, June 1992, Pl19-130
Slug and bailing tests were carried out in shallow wells in saprolite at two sites in the North Carolina Piedmont. Hydraulic conductivities were estimated from test results using McCarthy, Jacob-Theis, Skibitzke, Ferris-Knowles, Hvorslev, and Bouwer-Rice equations. Results are compared and discussed. It is suggested that several calculation methods be applied and ranges of values compared before selecting a single value for application. The geometric mean of a range of values is thought to be best for comparison between methods.
932136 Effect of clod size on hydraulic conductivity of compacted clay Houston, S L; Randeni, J S Geotech Test J V15, N2, June 1992, P123-128 Hydraulic conductivity of compacted clay measured in the field is relatively high compared to laboratory values. Largespecimen laboratory tests in a 195mm diameter permeameter indicate the size and gradation of the clods of clay prior to compaction can have significant influence on measured hydraulic properties. Comparison is made with results of other similar tests and it is concluded that for typical liner materials, the 2 orders of magnitude difference in laboratory and field hydraulic conductivities can be attributed to clod size and gradation effects. Revised laboratory test procedures are proposed to enable data of value for design purposes to be obtained.
932133 Hydraulic conductivity of compacted bentonite-sand mixtures Kenney, T C; van Veen, W A; Swallow, M A; Sungaila, M A Can Geotech d V29, N3, June 1992, P364-374
932137 Hydraulic conductivity of a recent estuarine silty clay at Bothkennar Leroueii, S; Lerat, P; Hight, D W; Powell, J J M Geoteclmique V42, N2, June 1992, P275-288
Bentonite-sand mixtures are widely used in waste barriers. Laboratory tests have been carried out to evaluate effects on hydraulic conductivity of mix content, compaction water content, system chemistry, and change of system chemistry. Continuity of bentonite matrix (adequate bentonite and good mixing) is necessary for low hydraulic conductivity. In wellcompacted mixes with up to 20% bentonite by dry weight, sand provides the load-supporting framework and dimensional stability. The fabric of the bentonite within this framework is little affected when system chemistry is changed from fresh to saline water.
Permeability of the Bothkennar clay has been examined. In situ properties were measured by pushed-in piezometers, selfboring permeameters, and the BAT system. Laboratory measurements used oedometers, triaxial cells, and a radial flow cell. A size effect and an anisotropy ratio, varying with the fabric but generally 1.5-2, are found. Pushed-in piezometers and the BAT system appear to underestimate the hydraulic conductivity. The self-boring permeameter provides the most representative profile. Variation of hydraulic conductivity with compression was quantified.
O 1993 Pergamon Press Ltd. Reproduction not permitted