Showing papers by "Delwyn G. Fredlund published in 2004"
TL;DR: In this article, a Tempe pressure cell and a capillary rise open tube were used to investigate drying and wetting soil-water characteristic curves (SWCCs) for five sandy soils.
Abstract: Drying and wetting soil-water characteristic curves (SWCCs) for five sandy soils are investigated using a Tempe pressure cell and capillary rise open tube. The test data are fitted to two SWCC equa...
200 citations
TL;DR: In this paper, a new class of equations to represent unimodal and bimodal SWCCs is proposed to overcome the difficulties of fitting parameters individually correspond to clearly defined soil properties or to features of the curve.
Abstract: The soil-water characteristic curve (SWCC) has traditionally been represented using equations whose fitting parameters do not individually correspond to clearly defined soil properties or to features of the curve. As a result, unique sets of parameters are often nonexistent, and sensitivity analyses and statistical assessments of SWCC parameters become difficult. In order to overcome these difficulties, a new class of equations to represent unimodal and bimodal SWCCs is proposed. The chosen fitting parameters are the air-entry value, the residual suction, the residual degree of saturation, and a parameter that controls the sharpness of the curvatures. The physical meaning for the soil parameters is discussed for different soil types. A unique relation between each of the equation parameters and the individual features of SWCCs is assured. The proposed equations are fitted to data corresponding to a variety of soil types and a good fit is observed.
113 citations
TL;DR: The effect of negative pore-water pressure on slope stability is often ignored in slope stability studies as discussed by the authors, and there is a perception among geotechnical engineers that negative PORE-water pressures will dissipate with rai
Abstract: The effect of negative pore-water pressure is often ignored in slope stability studies. There is a perception among geotechnical engineers that negative pore-water pressures will dissipate with rai...
110 citations
TL;DR: In this paper, the prediction of heave in unsaturated, expansive soils has been studied primarily as a one-dimensional type analysis, and a methodology that can be used for the predic...
Abstract: The prediction of heave in unsaturated, expansive soils has historically been studied primarily as a one-dimensional type analysis. This paper proposes a methodology that can be used for the predic...
92 citations
TL;DR: In this article, the authors investigated the capillary barrier effect on three soil columns of fine sand over medium sand, medium sand over gravelly sand, and coarse sand over ground soil.
Abstract: The capillary barrier effect was investigated by conducting infiltration tests on three soil columns of fine sand over medium sand, medium sand over gravelly sand, and fine sand over gravelly sand....
77 citations
TL;DR: In this paper, a physical model was designed and constructed to study the mechanisms associated with capillary barriers for slope stabilization purposes, and the model was used to evaluate the performance of various numerical algorithms.
Abstract: A physical model was designed and constructed to study the mechanisms associated with capillary barriers for slope stabilization purposes. Prior to construction of the model, various numerical anal...
58 citations
TL;DR: In this article, a physical capillary barrier model has been developed to study the mechanism and the effectiveness of a cappillary barrier for slope stabilization purposes, where simulated rainfalls of different intensities and durations representative of tropical climatic conditions were applied through a rainfall simulator.
Abstract: A physical capillary barrier model has been developed to study the mechanism and the effectiveness of a capillary barrier for slope stabilization purposes. A sloping two-layer capillary barrier model consisting of a relatively fine soil layer over a relatively coarse soil layer was constructed inside a specially designed apparatus. Simulated rainfalls of different intensities and durations representative of tropical climatic conditions were applied through a rainfall simulator. Various instruments consisting of tensiometers for pore-water pressure measurement, time domain reflectometry (TDR) for water content measurement, magnetic flow meter and electronic weight balances for water balance measurements were used in the experiment. The results obtained from various types of instrumentation were in good agreement. The experimental results show that the performance of the capillary barrier under the influence of a high precipitation rate is primarily governed by the storage capacity of the relatively fine soil of the capillary barrier.
52 citations