scholarly journals Analysis of the relationship between the water retention curve, particle size and pore size distribution in the characterization of a collapsible porous clay

Respuestas ◽  
2020 ◽  
Vol 25 (1) ◽  
pp. 33-43
Author(s):  
María Camila Olarte ◽  
Juan Carlos Ruge
Keyword(s):  
Particle Size ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Water Retention ◽  
Strong Relationship ◽  
Water Retention Curve ◽  
Retention Curve ◽  
Porous Soils

In highly porous soils with a susceptibility to collapse, there are points of volumetric variability, due to the present heterogeneity, regarding the diameters of the poral throat. The predominance of a pore size is closely related to certain values of the Water Retention Curve (WRC). However, to date, a possible correlation with particle size distribution (PaSD), obtained using modern, highly reliable gravitational sedimentation methods, has not been studied. The porous clay of lateritic origin under study, was characterized by means of index tests, to know its basic geotechnical behavior. Subsequently, it was analyzed by mercury intrusion porosimetry tests, to estimate the Pore Size Distribution (PSD); filter paper and pressure plate method to obtain the water retention curve; as well as the method of integral measurement of the pressure in the suspension (ISP), to obtain the fine grain size of the material. This article tries to present a proposal of relationship between these parameters, with the aim of improving the understanding in the characterization of this type of materials. The results showed that there is indeed a strong relationship between the particle size distributions, pore size distribution and the water retention curve. Mainly, this is reflected in the geometric places corresponding to the air value entries (AEV) of macropores and micropores. Which coincide with essential parameters of the behavior of the other curves (PaSD and PSD).

Models of the water retention curve for soils with a fractal pore size distribution

1996 ◽  
Vol 32 (10) ◽  
pp. 3025-3031 ◽  
Author(s):  
Edith Perrier ◽  
Michel Rieu ◽  
Garrison Sposito ◽  
Ghislain de Marsily
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Water Retention ◽  
Water Retention Curve ◽  
Retention Curve

Predicting water retention curves of fine texture soils from particle size distribution

2020 ◽  
Author(s):  
Joseph Pollacco ◽  
Jesús Fernández-Gálvez ◽  
Sam Carrick
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Hydraulic Properties ◽  
Water Retention ◽  
Pore Space ◽  
Water Retention Curve ◽  
Soil Hydraulic Properties ◽  
Retention Curve ◽  
Soil Particles

<p>Indirect methods for estimating soil hydraulic properties from particle size distribution have been developed due to the difficulty in accurately determining soil hydraulic properties, and the fact that particle size distribution is one piece of basic soil physical information normally available. The similarity of the functions describing the cumulative distribution of particle size and pore size in the soil has been the basis for relating particle size distribution and the water retention function in the soil. Empirical and semi-physical models have been proposed, but these are based on strong assumptions that are not always valid. For example, soil particles are normally assumed to be spherical, with constant density regardless of their size; and the soil pore space has been described by an assembly of capillary tubes, or the pore space in the soil matrix is assumed to be arranged in a similar way regardless of particle size. However, in a natural soil the geometry of the pores may vary with the size of the particles, leading to a variable relation between particle radius and pore radius.</p><p> </p><p>The current work is based on the hypothesis that the geometry of the pore size and the void ratio depends on the size of the soil particles, and that a physically based model can be generalised to predict the water retention curve from particle size distribution. The rearrangement of the soil particles is considered by introducing a mixing function that modulates the cumulative particle size distribution, while the total porosity is constrained by the saturated water content.</p><p> </p><p>The model performance is evaluated by comparing the soil water retention curve derived from laboratory measurements with a mean Nash–Sutcliffe model efficiency a value of 0.92 and a standard deviation of 0.08. The model is valid for all soil types, not just those with a marginal clay fraction.</p>

scholarly journals Effect of Biochar Particle Size on Physical, Hydrological and Chemical Properties of Loamy and Sandy Tropical Soils

Agronomy ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 165 ◽  
Author(s):  
Sara de Jesus Duarte ◽  
Bruno Glaser ◽  
Carlos Pellegrino Cerri
Keyword(s):  
Particle Size ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Sandy Soil ◽  
Water Retention ◽  
Tropical Soils ◽  
Total Carbon ◽  
Loamy Soil ◽  
Physical Chemical

The application of biochar is promising for improving the physical, chemical and hydrological properties of soil. However, there are few studies regarding the influence of biochar particle size. This study was conducted to evaluate the effect of biochar size on the physical, chemical and hydrological properties in sandy and loamy tropical soils. For this purpose, an incubation experiment was conducted in the laboratory with eight treatments (control (only soil), two soils (loamy and sandy soil), and three biochar sizes (<0.15 mm; 0.15–2 mm and >2 mm)). Analyses of water content, bulk density, total porosity, pore size distribution, total carbon (TC) and total N (TN) were performed after 1 year of soil–biochar-interactions in the laboratory. The smaller particle size <0.15 mm increased water retention in both soils, particularly in the loamy soil. Bulk density slightly decreased, especially in the loamy soil when biochar > 2 mm and in the sandy soil with the addition of 0.15–2 mm biochar. Porosity increased in both soils with the addition of biochar in the range of 0.15–2 mm. Smaller biochar particles shifted pore size distribution to increased macro and mesoporosity in both soils. Total carbon content increased mainly in sandy soil compared to control treatment; the highest carbon amount was obtained in the biochar size 0.15–2 mm in loamy soil and <0.15 mm in sandy soil, while the TN content and C:N ratio increased slightly with a reduction of the biochar particle size in both soils. These results demonstrate that biochar particle size is crucial for water retention, water availability, pore size distribution, and C sequestration.

Prediction of Water Retention Curve of a Layer Packed with Soil Particles from Particle Size Distribution

2012 ◽  
Vol 38 (5) ◽  
pp. 305-311
Author(s):  
Nobuhide Takahashi ◽  
Masataka Tsurukawa ◽  
Chikao Arai ◽  
Hiroshi Fukunaga ◽  
Koichi Yamada
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Water Retention ◽  
Water Retention Curve ◽  
Retention Curve ◽  
Soil Particles

Estimation of water retention curve of granular soils from particle-size distribution — a Bayesian probabilistic approach

2012 ◽  
Vol 49 (9) ◽  
pp. 1024-1035 ◽  
Author(s):  
C.F. Chiu ◽  
W.M. Yan ◽  
Ka-Veng Yuen
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Water Retention ◽  
Geometric Mean ◽  
Probabilistic Method ◽  
Probabilistic Approach ◽  
Water Retention Curve ◽  
Third Order ◽  
Retention Curve

This study proposes two empirical relationships to estimate the parameters of van Genuchten’s formula for modeling the water retention curve from the particle-size distribution. The relationships are determined by the Bayesian probabilistic method for selecting the most plausible class of models based on a database of 90 soil samples. The highest plausibility model among the selected relationships shows that the parameter α can be expressed as a first-order function of the particle size at 50% passing (d50) and parameter n is expressed as a third-order polynomial of the reciprocal of the standard deviation of geometric mean particle size (σg). The predictability of proposed relationships for other soils outside the calibrated database is also presented. It is found that the model prediction is highly consistent with the measurements for sands. However it only matches well with the measurements in the low suction regime for soils with at least 20% of fines content.

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