Using soil freezing characteristic curve to estimate the hydraulic conductivity function of partially frozen soils

2012 ◽  
Vol 83-84 ◽  
pp. 103-109 ◽  
Author(s):  
Tezera F. Azmatch ◽  
David C. Sego ◽  
Lukas U. Arenson ◽  
Kevin W. Biggar
Keyword(s):  
Hydraulic Conductivity ◽  
Characteristic Curve ◽  
Soil Freezing ◽  
Frozen Soils ◽  
Conductivity Function

A study on the geotechnical characterization and water retention characteristic curve of pond ash

2019 ◽  
Vol 80 (5) ◽  
pp. 929-938
Author(s):  
Janmeet Singh ◽  
Sanjay Kumar Singh ◽  
M. A. Alam
Keyword(s):  
Hydraulic Conductivity ◽  
Water Retention ◽  
Characteristic Curve ◽  
Input Parameter ◽  
Wetting And Drying ◽  
Pond Ash ◽  
Retention Characteristic ◽  
Unsaturated Hydraulic Conductivity ◽  
Conductivity Function ◽  
Engineering Practices

Abstract The understanding of the engineering behaviour of unsaturated soil is totally dependent on the water retention characteristic curve (WRCC). In this paper, a comprehensive study of the WRCCs of pond ash along with the ash's geotechnical behaviour has been made. The WRCC has been drawn experimentally using a Fredlund device based upon the pressure plate technique for both wetting and drying cycles. Further, an investigation was carried out to study WRCC hysteresis of pond ash. There exists a considerable hysteresis in drying and wetting curves of pond ash sample. The different WRCC models were used to fit the experimental WRCC data. The effect of compaction on WRCC was also studied. The air entry value in the case of a loose sample is low and the sample gets nearly desaturated at low soil suction as compared to a dense sample. Also, the wetting WRCC is predicted using the Feng and Fredlund model as it is difficult and time consuming to measure the whole hysteresis. The predicted results are compared with the measured wetting WRCC. Since the direct measurement of unsaturated hydraulic conductivity is difficult to obtain in engineering practices, the unsaturated hydraulic conductivity function is predicted using the measured WRCC as the input parameter using SEEP/W software.

Physically based closed-form expression for the bimodal unsaturated hydraulic conductivity function

2013 ◽  
Vol 68 (2) ◽  
pp. 328-334
Author(s):  
Shiyu Liu ◽  
Noriyuki Yasufuku ◽  
Qiang Liu ◽  
Hazarika Hemanta
Keyword(s):  
Experimental Data ◽  
Hydraulic Conductivity ◽  
Closed Form ◽  
Characteristic Curve ◽  
Complex Structure ◽  
Closed Form Expression ◽  
Form Expression ◽  
Unsaturated Hydraulic Conductivity ◽  
Physically Based ◽  
Conductivity Function

Simulation of flow and contaminant transport through the vadose zone requires accurate parameterization of the soil hydraulic properties. This requirement is particularly important for soils with a complex structure. In the present study, a physically based closed-form expression for the bimodal unsaturated hydraulic conductivity function is proposed for soils with bimodal pore-size distribution. It combines the bimodal representation of the soil-water characteristic curve (SWCC) function of Liu with the conductivity representation model of Mualem. The proposed equations are defined by parameters that have physical significance, which can be related to the properties of the materials. Experimental data for the representation of bimodal SWCCs and corresponding hydraulic conductivity curves were used to demonstrate the applicability of the proposed functions. The proposed approaches resulted in good agreement with experimental data. These functions can potentially be used as an effective tool for identifying hydraulic porosities in mediums with a complex structure.

scholarly journals Statistical Assessment of Hydraulic Properties of Unsaturated Soils

2016 ◽  
pp. 81-95
Author(s):  
Gilson de F. N. Gitirana ◽  
Delwyn G. Fredlund
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Properties ◽  
Unsaturated Soil ◽  
Unsaturated Soils ◽  
Hydraulic Properties ◽  
Characteristic Curve ◽  
Primary Objective ◽  
Soil Parameters ◽  
Statistical Assessment ◽  
Conductivity Function

The availability of statistical values for soil parameters is essential in reliability-based geotechnical design and sensitivity analysis. Unfortunately, there are few statistical studies available about unsaturated soil parameters. The primary objective of this paper is to present a methodology for the statistical assessment of hydraulic properties of unsaturated soil and to present the results of a statistical study carried out using a large database of soil properties. Two fundamental unsaturated soil properties are considered; namely, the soil-water characteristic curve (SWCC) and the hydraulic conductivity function. Appropriate nonlinear functions and fitting parameters with well-defined and unique physical and/or geometrical meanings were adopted. The main contribution of this article is the establishment of central tendency measures, standard deviations, and correlation coefficients for the unsaturated soil parameters, considering soil datasets grouped according to soil texture. It was determined based on the analyses results that the air-entry value, primary SWCC slope, residual SWCC slope, saturated hydraulic conductivity, and hydraulic conductivity function slope could be well described using lognormal probability density functions. Finally, general guidelines are provided regarding the statistical values to be adopted for the unsaturated soil properties studied.

Relationship between the Hydraulic Conductivity Function and the Particle-Size Distribution

2003 ◽  
Vol 67 (1) ◽  
pp. 373
Author(s):  
Lalit M. Arya ◽  
Feike J. Leij ◽  
Peter J. Shouse ◽  
Martinus Th. van Genuchten
Keyword(s):  
Particle Size ◽  
Hydraulic Conductivity ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Conductivity Function
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