On the dependence of the saturated hydraulic conductivity upon the effective porosity through a power law model at different scales

2016 ◽  
Vol 30 (13) ◽  
pp. 2366-2372 ◽  
Author(s):  
Carmine Fallico ◽  
Samuele De Bartolo ◽  
Massimo Veltri ◽  
Gerardo Severino
Keyword(s):  
Hydraulic Conductivity ◽  
Power Law ◽  
Effective Porosity ◽  
Saturated Hydraulic Conductivity ◽  
Power Law Model

A Model for the Relationship between the Hydraulic Conductivity and Primary Sedimentary Structures of Till

1989 ◽  
Vol 20 (3) ◽  
pp. 137-152 ◽  
Author(s):  
Mats R. Nyborg
Keyword(s):  
Hydraulic Conductivity ◽  
Flow Direction ◽  
Effective Porosity ◽  
Saturated Hydraulic Conductivity ◽  
Minor Importance ◽  
Axis Orientation ◽  
Constant Head ◽  
Soil Forming Processes ◽  
Capillary Pressure Curves ◽  
Directional Relations

An investigation has been made of the relationships between saturated hydraulic conductivity, porosity and micro-structure of undisturbed lodgement till samples. 35 measurements with a constant head laboratory permeameter are the basis for the discussion. All the measurements were made on undisturbed till samples. In order to minimize the effects of soil forming processes and to have the most homogeneous conditions all sampling were made from the C-horizon. The samples have a size of about 300 cm3. Porosity data were derived from capillary pressure curves. A model for how flow direction and long-axis orientations of elongated grains relate to the saturated hydraulic conductivity is presented. For an unsorted sediment such factors as grain size are concluded to be of minor importance for the hydraulic conductivity. The structural properties seem to be a more important factor. This effect can be explained in two ways. Either due to directional relations between sorted lenses and bands which have higher permeability and the flow route through the sample. The other explanation is due to a more continuous pore pattern parallel to the grain orientation. The hydraulic conductivity takes on a directional property, being smaller in directions normal to the structural long-axis orientation than in directions parallel to the orientation. A study of the effective porosity Versus hydraulic conductivity exhibits weak correlation.

Prediction of hydraulic conductivity for some Australian soils

Soil Research ◽  
2003 ◽  
Vol 41 (6) ◽  
pp. 1077 ◽  
Author(s):  
Zahra Paydar ◽  
Anthony J. Ringrose-Voase
Keyword(s):  
Hydraulic Conductivity ◽  
Water Retention ◽  
Management Practices ◽  
Measurement Techniques ◽  
Effective Porosity ◽  
Saturated Hydraulic Conductivity ◽  
Pedotransfer Functions ◽  
Water Retention Curve ◽  
Soil Water Retention Curve ◽  
Soil Water Retention

Pedotransfer functions and their use in simulation modelling have attracted much attention during recent years. In the absence of measured hydraulic conductivity data, prediction from other soil properties would be most useful. A functional form relating near-saturated hydraulic conductivity to the soil water retention curve based on the Kozeny–Carman equation was investigated on Australian soils. For a dataset comprising a range of soil textures and structural conditions (107 samples with bulk density >1.2 Mg/m3) a power-law relationship between near-saturated hydraulic conductivity, effective porosity, and pore size distribution index was obtained. The function was tested on 2 different datasets for independent evaluation. The results showed poor predictions for most soils in this study. While the reasons for poor predictions might be the difference in the measurement techniques or potentials, it is thought that the proposed function mostly fails predictions on soils with high organic matter and management practices affecting macropores and soil structure (e.g. crust). The proposed function did not show much improvement over the more general form of the Kozeny–Carman equation with empirical coefficients. In the absence of other data, the modified Kozeny–Carman equation (with or without water retention parameters) can be used, with caution, on similar soils and larger scale applications. More data are needed to test the reliabilty of these functions for use in specific locations.

Saturated Hydraulic Conductivity of Clayey Tills and the Role of Fractures

1990 ◽  
Vol 21 (2) ◽  
pp. 119-132 ◽  
Author(s):  
Johnny Fredericia
Keyword(s):  
Hydraulic Conductivity ◽  
American Studies ◽  
Field Measurements ◽  
Present Knowledge ◽  
Saturated Hydraulic Conductivity ◽  
Field Observations ◽  
Laboratory Measurements ◽  
Vertical Hydraulic Conductivity ◽  
Data Field

The background for the present knowledge about hydraulic conductivity of clayey till in Denmark is summarized. The data show a difference of 1-2 orders of magnitude in the vertical hydraulic conductivity between values from laboratory measurements and field measurements. This difference is discussed and based on new data, field observations and comparison with North American studies, it is concluded to be primarily due to fractures in the till.

Changes over time in near‐saturated hydraulic conductivity of peat soil following reclamation for agriculture

2019 ◽  
Vol 34 (2) ◽  
pp. 237-243
Author(s):  
Jari Hyväluoma ◽  
Mari Räty ◽  
Janne Kaseva ◽  
Riikka Keskinen
Keyword(s):  
Hydraulic Conductivity ◽  
Peat Soil ◽  
Saturated Hydraulic Conductivity ◽  
Changes Over Time ◽  
Over Time

scholarly journals Polyconvex hyperelastic modeling of rubberlike materials

2021 ◽  
Vol 43 (7) ◽  
Author(s):  
Cyprian Suchocki ◽  
Stanisław Jemioło
Keyword(s):  
Experimental Data ◽  
Power Law ◽  
Curve Fitting ◽  
Constitutive Relations ◽  
Data Sets ◽  
Power Law Model ◽  
Stored Energy ◽  
Data Approximation ◽  
Exponential Power ◽  
Hyperelastic Models

AbstractIn this work a number of selected, isotropic, invariant-based hyperelastic models are analyzed. The considered constitutive relations of hyperelasticity include the model by Gent (G) and its extension, the so-called generalized Gent model (GG), the exponential-power law model (Exp-PL) and the power law model (PL). The material parameters of the models under study have been identified for eight different experimental data sets. As it has been demonstrated, the much celebrated Gent’s model does not always allow to obtain an acceptable quality of the experimental data approximation. Furthermore, it is observed that the best curve fitting quality is usually achieved when the experimentally derived conditions that were proposed by Rivlin and Saunders are fulfilled. However, it is shown that the conditions by Rivlin and Saunders are in a contradiction with the mathematical requirements of stored energy polyconvexity. A polyconvex stored energy function is assumed in order to ensure the existence of solutions to a properly defined boundary value problem and to avoid non-physical material response. It is found that in the case of the analyzed hyperelastic models the application of polyconvexity conditions leads to only a slight decrease in the curve fitting quality. When the energy polyconvexity is assumed, the best experimental data approximation is usually obtained for the PL model. Among the non-polyconvex hyperelastic models, the best curve fitting results are most frequently achieved for the GG model. However, it is shown that both the G and the GG models are problematic due to the presence of the locking effect.

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