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This paper examines and assesses predictive methods for the saturated hydraulic conductivity of soils. The soil definition is that of engineering. It is not that of soil science and agriculture, which corresponds to 'top soil' in engineering. Most predictive methods were calibrated using laboratory permeability tests performed on either disturbed or intact specimens for which the test conditions were either measured or supposed to be known. The quality of predictive equations depends highly on the test quality. Without examining all the quality issues, the paper explains the 14 most important mistakes for tests in rigid-wall or flexible-wall permeameters. Then, it briefly presents 45 predictive methods, and in detail, those with some potential, such as the Kozeny-Carman equation. Afterwards, the data of hundreds of excellent quality tests, with none of the 14 mistakes, are used to assess the predictive methods with a potential. The relative performance of those methods is evaluated and presented in graphs. Three methods are found to work fairly well for non-plastic soils, two for plastic soils without fissures, and one for compacted plastic soils used for liners and covers. The paper discusses the effects of temperature and intrinsic anisotropy within the specimen, but not larger scale anisotropy within aquifers and aquitards. [ABSTRACT FROM AUTHOR]

This study was performed in order to evaluate the permeability of the basalts and pyroclastics and the maximum depth of grout injection at the Atasu dam site, Turkey, using the equations of Kiraly and Hoek and Bray based on values obtained from Lugeon tests. In order to evaluate maximum discharge values and depth of injection, seepage analyses were performed using the finite element technique for each 10 m up to 100 m. The results indicate that to establish an impermeable zone at the dam site, the depth of injection should be taken as 50 m for the left and right slopes and 40 m for the river bed. [ABSTRACT FROM AUTHOR]

Tension-induced fractures and fractures formed by saw-cut surfaces and polished surfaces were prepared in salt specimens. A series of gas flow testing was performed to monitor the changes of the fracture permeability under quasi-static loading (0.7-20 MPa) for up to 120 h. Healing tests under static loading were carried out under both dry and saturated conditions. The results suggest that the primary factors governing the healing of salt fractures are the origin and purity of the fractures, and the magnitude and duration of the fracture pressurization. Inclusions or impurities significantly reduce healing effectiveness. The hydraulic conductivity of fractures in pure salt can be reduced permanently by more than 4 orders of magnitude with applied stresses of 20 MPa for a relatively short period. In most cases the reduction of salt fracture permeability is due to fracture closure, which does not always lead to fracture healing. The closure involves visco-plastic deformation of the asperities on both sides of the salt fracture, while the healing is related to the covalent bonding between the two surfaces. Fracture roughness and brine saturation appeared to have an insignificant impact on the healing process. [ABSTRACT FROM AUTHOR]

Using the Dupuit assumptions, a new closed-form solution is established for steady-state pumping of an ideal unconfined aquifer that is recharged by infiltration. This new solution is complete for the two-part mathematical domain, which was not the case for previously partial solutions. A second new solution is then provided for the travel time of a non-reactive tracer to the pumping well, under steady-state conditions. The travel time integral has no known closed-form solution, but is easy to calculate, either numerically or using a simplified equation. The numerical calculation and the simplified equation give travel times very close to those obtained using finite element codes for saturated and unsaturated groundwater flow and particle tracking. [ABSTRACT FROM AUTHOR]

This paper reviews analytical solutions for steady state seepage of groundwater in an ideal sloping unconfined aquifer, recharged by an effective infiltration, when the unsaturated seepage is neglected. Available solutions are examined and compared. Their robustness is assessed with a finite element code, which solves the complete equations for saturated and unsaturated flow, thus making none of the simplifying assumptions of the theoretical solutions. An example is provided for a sloping aquifer on the north shore of the Saint-Lawrence River. [ABSTRACT FROM AUTHOR]

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Copyright of Bulletin of Engineering Geology & the Environment is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)