886141 Permeability changes during shear deformation of fractured rock

218A 886136 Determining soil hydraulic properties by parameter estimation: on the selection of a model for the hydraulic properties Russo, D Water Resour Res V24, N3, March 1988, P453-459 The combined water retention-hydraulic conductivity models of Brooks and Corey (1964) and van Genuchten (1980) and the soil hydraulic conductivity function of Gardner (1958) are evaluated as candidate models of soil hydraulic properties in terms of accuracy and consistency with experimental data. Soil hydraulic properties are determined from transient flow experiments by the parameter estimation method of Kool et al (1985). Model selection, including hypothesis on model structure, estimation of parameters, model validation and model discrimination testsjs demonstrated for two different soils. 886137 Dependence of anisotropy on saturation in a stratified sand Stephens, D B; Heerman, S Water Resour Res V24, N-5. May 1988, P770-778 Laboratory experiments investigated movement of water infiltrating from a point source into alternate layers of fine and coarse sand, in order to determine whether effective anisotropy is dependent on saturation. Dyes were used to map specific discharge direction, and tensiometers used to characterise hydraulic gradient field under unsaturated steady state conditions. Results indicate that for unsaturated thinly layered soils, effective anisotropy increases as pressure head and saturation decrease. 886138 Stationary principles for Row and transport in aquifers Sorek, S Proc NATO Advanced Research Workshop on Advances in Analytical and Numerical Groundwater Flow and Quality Modeling, Lisbon, 2-6 June 1987 Pill-116. Pub1 Dordrecht: Reidel, 1987 Flow and transport through porous media have been numerically modelled using a stationary integral approach. Schemes are based on variational concepts applied to integrals over rate of energy terms (flow governing) and rate of momentum terms (transport governing). Resulting equations describe solutions of the hydraulic head and solute concentration, and the relation between concentration field and velocity field. 886139 Some recent developments in understanding the hydrology of fractured rocks Wi therspoon, P A; Long, J C S Proc 28th US Symposium on Rock Mechanics, Tucson, 29 June-l July 1987 P421-432. Pub1 Rotterdam: A A Balkema, 1987 Modelling the behaviour of fluid flow in a fractured rock is largely a problem of defining fracture geometry. Research on two scales, the single fracture and fracture networks, is presented. For the single fracture, the void geometry is investigated using metal casts and mercury injection,and flow caculations made based on Navier-Stokes equations. The geometry of fracture networks is studied using statistical analysis (a parent-daughter model), geophysical techniques (seismic tomography studies for fracture detection and characterisation), and prediction of fracture mechanisms through the application of rock mechanics. 0

886140 Characterizing the hydraulic properties of fractured rock masses. Methodology and case studies Hsieh, P A Proc 28th US Symposium on Rock Mechanics, Tucson, 29 June-l July 1987 P465-472. Pub1 Rotterdam: A A Balkema, 1987 A method developed to determine hydraulic properties on a large scale, and investigate the relation between fracturing and anisotropy is presented. Background information on fractures is provided by geophysical and geological investigations and conventional single-hole packer tests. Anisotropy is investigated using a cross-hole test. The method is illustrated for crystalline rocks in Arizona and New Hampshire. Results indicate there may not be a unique approach to characterise the hydraulic properties of fractured rock masses. A multitude of different techniques is required for rocks at different scales. 886141 Permeability changes during shear deformation of fractured rock Teufel, L W Proc 28th US Symposium on Rock Mechunics, Tucson, 29 June-l July 1987 P473-480. Publ Rotter&m: A A Balkema, 1987 The effect of shear deformation on the permeability of a fractured rock has been studied using drained triaxial compression tests on prefractured sandstone at effective confining pressures ranging from 15 to 60 MPa. Petrographic and SEM techniques were used to analyse how the deformation is distributed within the fractured samples, and the relation between permeability changes and deformation mechanisms. Results indicate that permeability across a fracture increases with increased shear deformation due to local&d deformation along fractures and the development of a gouge zone. Also, there is a progressive decrease in grain size and porosity of the gouge zone with increasing shear displacement. 886142 Influence of stress-induced defortnatlons on observed water flow in fractures of the Climax Granltic Stock Wilder, D G Proc 28th US Symposium on Rock Mechanics, Tucson, 29 June-l July 1987 P491-499. Pub1 Rotterdam: A A Balkema, 1987 Observations of the location of seepage relative to fractures and their orientation relative to changes in stress are presented. Three examples of the influence of stress-induced displacements on the hydrology of fractured granite are identified: (1) preferential seepage into underground workings from shear zones; (2) seepage from low angle joint sets which are healed and tight; and (3) mineral infilling of vertical joints indicating preferential seepage the through some joints over extended periods of time, related to shear stresses on the fractures at a time when normal stresses were low. 886143 Fracture fkrw response to applied stress: A field study Sour, L; Ubbes, W Proc 28th US Symposium on Rock Mechunics, Tucson, 29 June-l July 1987 MOI-508. Pub1 Rotterdam: A A Balkema, 1987 Analysis of mechanical and hydrological responses of a single fracture under controlled stress conditions in situ is presented. Stress up to 7MPa was applied in 4 configurations - normal /compression, clockwise shear, counter-clockwise shear and tension - whilst conductivity was monitored. Permeability

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