Density Influence on Matric Suction of the Eolian Sand under the Condition of Loop of Dehumidifying and Humidifying Process

2011 ◽  
Vol 250-253 ◽  
pp. 2157-2160
Author(s):  
Yan Xun Song ◽  
Qiang Xu ◽  
Xi An Li ◽  
Hong Zhou Lin
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Matric Suction ◽  
Dry Density ◽  
Test Results ◽  
Unsaturated Sand ◽  
Water Characteristics ◽  
Eolian Sand ◽  
The Relationship ◽  
Variation Tendency

The matric suction has very important influence on the characteristics of unsaturated sand; and it is closely relevant to density. In order to discuss the relationship among the matric suction, water content and dry density, the matric suction of the eolian sand were measured in laboratory. The soil-water characteristics curves for unsaturated eolian sand with different dry densities are obtained. The test results show that the variation tendency of soil-water characteristics curves has been corresponding to the different densities.

Study on the Test of Soil Water Characteristic Curve

2011 ◽  
Vol 261-263 ◽  
pp. 1094-1098
Author(s):  
Yu You Yang ◽  
Qin Xi Zhang ◽  
Gui He Wang ◽  
Chen Liu
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Unsaturated Soil ◽  
Characteristic Curve ◽  
Mathematic Model ◽  
Matric Suction ◽  
Engineering Properties ◽  
Soil Water Characteristic Curve ◽  
Van Genuchten Model ◽  
The Relationship

The test of soil water characteristic curve (SWCC) and its mathematic model are present. The SWCC can describe the relationship between unsaturated soil matric suction and water content. Matric suction is an important parameter to address when studying the engineering properties of unsaturated soil. And while the measurement of substrate attraction is a very difficult issue, it is also one of the biggest obstacles in the engineering applications of unsaturated soil. By analyzing and researching the test data of SWCC researchers can initially establish the mathematic model which is the SWCC equation. The Van Genuchten model and the Fredlund and Xing model were used to simulate better the changes between the volume water content and the matric suction. Predictions were compared with experimental results to determine the simulation capability of the model for the soil of Beijing.

Experimental Research of Matrix Suction of the Unsaturated Red Clay

2014 ◽  
Vol 919-921 ◽  
pp. 835-838 ◽  
Author(s):  
Wen Feng Zhao ◽  
Long Li ◽  
Yu Hang Xiao
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Characteristic Curve ◽  
Matric Suction ◽  
High Water Content ◽  
Dry Density ◽  
Red Clay ◽  
Soil Water Characteristic Curve ◽  
Matrix Suction ◽  
The Impact

Matric suction has great impact on the strength of soil. Some physico-mechanical indexes, such as the water content, dry density of soil, have close relationship with the matric suction. The experiments were conducted in the laboratory to study the relationship between the matric suction, the water content and dry density of unsaturated red clay. The filter paper method was used to get the soil-water characteristic curve of the unsaturated red clay. The results show that: water content has great impact on matrix suction. The soil-water characteristic curve can be divided into three stages. In low water content area, matrix suction decreases rapidly with the increase of water content.Then, the rate of change slows down after the inflection point. Matrix suction increases obviously with the increase of dry density under the condition of low water content, but the impact disappears under high water content. So the matrix suction is affected by dry density and water content.

Soil-water characteristic curves of clays

2014 ◽  
Vol 51 (8) ◽  
pp. 869-883 ◽  
Author(s):  
Snehasis Tripathy ◽  
Mohd Yuhyi M. Tadza ◽  
Hywel Rhys Thomas
Keyword(s):  
Polyethylene Glycol ◽  
Water Content ◽  
Soil Water ◽  
Matric Suction ◽  
Degree Of Saturation ◽  
Chemical Analyses ◽  
Test Results ◽  
Characteristic Curves ◽  
Soil Water Characteristic Curves

The drying suction – water content soil-water characteristic curves (SWCCs) of three clays (MX80 bentonite, yellow bentonite, and Speswhite kaolin) were experimentally determined using axis-translation, vapour equilibrium, and osmotic techniques. The shrinkage paths of the clays were established from Clod tests. The suction – water content SWCCs in conjunction with the Clod test results enabled establishing the suction – degree of saturation SWCCs and further determination of the air-entry values (AEVs) of the clays. Chemical analyses of the polyethylene glycol (PEG) solutions in the osmotic tests revealed an imbalance of the osmotic suctions between the expelled and the retained salts on either side of semi-permeable membranes. A decrease in the water content due to an applied suction for clays with significant osmotic efficiencies was explained by two mechanisms. In mechanism 1, the water content decrease prior to the air entry is controlled by the interparticle repulsive pressure, and in mechanism 2, a decrease in the degree of saturation following the air entry is primarily due to the matric suction. The agreements between the AEVs of the clays determined based on the osmotic suctions corresponding to various applied suctions and that determined from the suction – degree of saturation SWCCs were found to be very good.

scholarly journals Soil–Water Retention Curves Derived as a Function of Soil Dry Density

GeoHazards ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 3-19 ◽  
Author(s):  
Yulong Chen
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Unsaturated Soils ◽  
Water Retention ◽  
Matric Suction ◽  
Soil Samples ◽  
Volumetric Water Content ◽  
Proton Nuclear Magnetic Resonance ◽  
Dry Density ◽  
Soil Water Retention

The soil–water retention curves (SWRC) of soil plays a key role in unsaturated soil mechanics, which is a relatively new field of study having wide applications particularly in geotechnical and geo-environmental engineering. SWRCs were used to evaluate the ability of unsaturated soils to attract water with various water contents and matric suctions. Drying and wetting SWRCs for a sandy soil with different dry densities were studied in a laboratory. Proton nuclear magnetic resonance, image processing technology, and mercury intrusion porosimetry were used to characterize the microscopic mechanisms of pore size distribution in the soil. Soil–water retention in the soil samples was strongly dependent on the dry density. With zero matric suction, soil samples with a higher dry density had a lower initial volumetric water content. Volumetric water content changed at a slower rate when values of matric suction increased in soils with a higher dry density. Soil samples had residual matric suction and a larger air-entry value with a smaller slope of the SWRC when they had a higher density. Dry density change is mainly responsible for the large pores. The number of large pores decreased as dry density increased. As the dry density increased, the area of macropores occupying the largest portion decreased, while the area of mesopores and micropores increased. Minipores accounted for the smallest proportion of total area and they were nearly constant. The proportion of large diameter pores decreased relative to pores with small diameters in the tested soils. The total pore volume was lower for soil specimens that had larger dry densities, as compared to relatively loose specimens. There was hysteresis between the drying and wetting curves for all soil samples. Hysteresis decreased as the dry density of the soil increased. The different liquid–solid contact angle was the main factor causing hysteresis of SWRC.

Soil Water Characteristic Curve and its Applications in Tunnel

2011 ◽  
Vol 261-263 ◽  
pp. 1039-1043
Author(s):  
Yu You Yang ◽  
Qin Xi Zhang ◽  
Gui He Wang ◽  
Jia Xing Yu
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Land Subsidence ◽  
Unsaturated Soil ◽  
Characteristic Curve ◽  
Tunnel Construction ◽  
Coupling Theory ◽  
Engineering Analysis ◽  
Soil Water Characteristic Curve ◽  
The Relationship

A soil water characteristic curve (SWCC) can describe the relationship between unsaturated soil matric suction and water content. By analyzing and researching the test data of the soil water characteristic curve researchers can initially establish the SWCC equation and apply this equation to the actual engineering analysis. In another words, this article is based on the fluid-solid coupling theory of unsaturated soil used to analyze and study the problem of land subsidence caused by tunnel construction. Numerical calculations show that the coupling results agree well with the measured curve works.

The relationship between solar radiation interception and soil water content in a tropical deciduous forest in Mexico

CATENA ◽  
1999 ◽  
Vol 36 (1-2) ◽  
pp. 153-164 ◽  
Author(s):  
L Galicia ◽  
J López-Blanco ◽  
A.E Zarco-Arista ◽  
V Filips ◽  
F Garcı́a-Oliva
Keyword(s):  
Solar Radiation ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Deciduous Forest ◽  
Tropical Deciduous Forest ◽  
Radiation Interception ◽  
The Relationship

The Study of Correction Method for Soil-Water Characteristic Curve of Swelling-Shrinking Soil

2013 ◽  
Vol 712-715 ◽  
pp. 873-876
Author(s):  
Peng Du ◽  
Xiao Ling Liu ◽  
Xiao Ying Li
Keyword(s):  
Soil Water ◽  
Volume Fraction ◽  
Characteristic Curve ◽  
Correction Method ◽  
Matric Suction ◽  
Engineering Properties ◽  
Water Volume ◽  
Volume Deformation ◽  
Water Volume Fraction ◽  
The Relationship

The swelling-shrinking soil embodies the features of expanding when absorbing water and shrinking when drying out; its engineering properties are sensitive to water fluctuation. Mainstream test instruments of SWCC cannot accurately get its relationship between matric suction and water volume fraction. So a correction method based on the results of shrinkage test is carried out. The method is accomplished by using the volume deformation which is obtained in shrinkage test to calculate its real water volume fraction and then combining the results of SWCC test and finally constructing the relationship between matric suction and water volume fraction. Through real application, this method is proved to be feasible and essential.

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