scholarly journals Comparison between Soil-Water Characteristic Curves based on filter paper method and grain-size distribution/volume-mass prediction: An evaluation of input data stemmed from hydrometer and Cilas grain-size analyser

2020 ◽  
Vol 195 ◽  
pp. 03027
Author(s):  
Marcos Felipe da Silva André ◽  
Thiago de Souza Carnavale
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Soil Water ◽  
Grain Size Distribution ◽  
Filter Paper ◽  
Input Data ◽  
Characteristic Curves ◽  
Filter Paper Method ◽  
Soil Water Characteristic Curves ◽  
Paper Method

The current paper aims to present a comparison between soil-water characteristic curves based on the filter paper method and on a volume-mass estimation. Additionally, this research consists in comparing grain size distributions by sieving/hydrometer and by sieving/Cilas (particle-size analyser model 1092), when it comes to determining the soil-water characteristic curves by a volume-mass prediction on the Soil Vision software. As materials, were used two sets of colluvial soils sampled at the Campus Quinta do Paraiso -Centro Universitário Serra dos Órgãos (UNIFESO), Teresópolis – Brazil. The results showed that the soil-water characteristic curves related to the filter paper method or grain size distribution estimation are different. However, the tests performed by sieving/Cilas are more efficient than the results based on sieving/hydrometer, concerning its uses as input data for soil-water characteristic curves estimations. In conclusion, even considering the estimation method was not able to depict the same results such as obtained by the filter paper method, the use of Cilas is a procedure that can improve the quality of the predicted soil-water characteristic curve.

Factors affecting drying and wetting soil-water characteristic curves of sandy soils

2004 ◽  
Vol 41 (5) ◽  
pp. 908-920 ◽  
Author(s):  
Hong Yang ◽  
Harianto Rahardjo ◽  
Eng-Choon Leong ◽  
D G Fredlund
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Soil Water ◽  
Grain Size Distribution ◽  
Sandy Soils ◽  
Water Entry ◽  
Matric Suction ◽  
Dry Density ◽  
Characteristic Curves ◽  
Soil Water Characteristic Curves

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 equations using a least-squares algorithm. The obtained fitting parameters and some hysteretic behaviour are discussed and correlated with grain-size distribution parameters. A concept of total hysteresis is proposed to quantify the hysteresis of SWCC. The measured SWCC for one soil is also compared with the SWCC estimated from its grain-size distribution. The SWCC was also obtained at a high dry density for one of the soils. The results show that the shapes of the SWCCs are similar to the grain-size distributions of the soils and are affected by the dry density of the soil. A coarse-grained soil has a lower air-entry value, residual matric suction, and water-entry value and less total hysteresis than a fine-grained soil. The residual matric suction and water-entry value tend to approach the same value when the effective grain size D10 of the soil is small, in the range of 3-6 mm. SWCCs of uniform soils have steeper slopes and less total hysteresis than those of less uniform soils. Soils with a low dry density have a lower air-entry value and residual matric suction than soils with a high dry density. The SWCC predicted from grain-size distribution is found to be sufficiently accurate.Key words: soil-water characteristic curve, water content, suction, hysteresis, grain size.

Laboratory Tests on Hydraulic Properties of Municipal Solid Waste

2013 ◽  
Vol 726-731 ◽  
pp. 2547-2552
Author(s):  
Li Hua Song
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Soil Water ◽  
Filter Paper ◽  
Laboratory Tests ◽  
Hydraulic Properties ◽  
Characteristic Curves ◽  
Filter Paper Method ◽  
Soil Water Characteristic Curves ◽  
Paper Method

In order to analyze the hydraulic properties of municipal solid waste (MSW), laboratory tests on the soil-water characteristic curves of 6 groups of MSW samples with different void ratios and organic contents are performed by means of the unsaturated consolidation apparatus. The filter paper method is also employed to determine their soil-water characteristic curves. The distribution indexλof void size of the samples is analyzed. The results show that the air-entry value of the MSW samples is very small and about 1kPa, and it increases owing to the action of loading. The value ofλ decreases with the increase of the initial void ratio and increases with the increase of the organic content in the samples. For measuring the soil-water characteristic curves of MSW by means of the filter paper method, the values at high suction phase are more rational and significant.

scholarly journals Evaluation of prediction models applied to the soil-water characteristic curve of ideal materials

2020 ◽  
Vol 195 ◽  
pp. 02024
Author(s):  
Roberto Dutra Alves ◽  
Gilson de F. N. Gitirana ◽  
Sai K. Vanapalli
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Soil Water ◽  
Grain Size Distribution ◽  
Characteristic Curve ◽  
Empirical Models ◽  
Spherical Particles ◽  
Soil Water Characteristic Curve ◽  
Varying Coefficients ◽  
Semi Empirical

The development of theoretical and semi-empirical models to study capillary mechanisms and predict the soil-water characteristic curve (SWCC) generally requires the idealization of pore space and pore water, considering simplifying hypotheses. The study of ideal materials comprised of particles with controlled shape and size allows the evaluation of such simplifying hypotheses and the subsequent generalization to actual soils. In this paper, four theoretical and semi-empirical models for the prediction of the SWCC are applied to the prediction of artificial materials comprised of spherical particles. Nineteen grain-size distribution curves, with varying coefficients of uniformity are considered. The dataset is comprised of materials previously published and additional tests carried out by the authors, under highly controlled conditions. The analyses allowed the evaluation of the effect of grain-size distribution curve and shape of the particles. The limitations and advantages of each prediction model was investigated, and a detailed comparison is presented, guiding future implementations of improved models.

On the prediction of hydraulic conductivity of frozen soils

1996 ◽  
Vol 33 (1) ◽  
pp. 176-180 ◽  
Author(s):  
Vlodek R Tarnawski ◽  
Bernhard Wagner
Keyword(s):  
Grain Size ◽  
Hydraulic Conductivity ◽  
Water Content ◽  
Bulk Density ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Input Data ◽  
Unfrozen Water ◽  
Frozen Soils ◽  
Unfrozen Water Content

This paper describes a mathematical model for predicting the hydraulic conductivity of partially frozen soils on the basis of limited input data such as grain size distribution and bulk density or porosity. A new model is based on an analogy for the hydraulic conductivity of frozen and unfrozen soils and models for the estimation of hydraulic properties of soils and unfrozen water content. Campbell's model was used for prediction of soil-water characteristics from limited data, while unfrozen water content was obtained from two models (by P.J. Williams and D.M. Anderson) applied to two different temperature ranges. The new model can be used for the rapid estimation of the hydraulic conductivity of practically any freezing soil having log-normal grain size distribution and for computer simulation of moisture migration in soils below the freezing point. An acceptable conformity between the model prediction and measured data for pure sand has been achieved. The computer program developed requires the following input data: grain size distribution, bulk density or porosity, and soil temperature. Key words: frozen soils, hydraulic conductivity, bulk density, grain size distribution, unfrozen water content.

Sign in / Sign up

Export Citation Format

Share Document