Influence of initial dry density and water content on the soil–water characteristic curve and suction stress of a reconstituted loess soil

2016 ◽  
Vol 76 (3) ◽  
pp. 1085-1095 ◽  
Author(s):  
Yao Jiang ◽  
Wenwu Chen ◽  
Gonghui Wang ◽  
Guanping Sun ◽  
Fanyu Zhang
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Characteristic Curve ◽  
Loess Soil ◽  
Dry Density ◽  
Soil Water Characteristic Curve ◽  
Suction Stress

Research on Soil-Water Characteristic Curve of Unsaturated Mixed-Soil in West Sichuan

2013 ◽  
Vol 353-356 ◽  
pp. 996-1000
Author(s):  
Wei Guang Zhou ◽  
Yu Long Bao ◽  
Hong Bin Zhou
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Unsaturated Soils ◽  
Characteristic Curve ◽  
Clay Content ◽  
Dry Density ◽  
Residual Moisture ◽  
Soil Water Characteristic Curve ◽  
Physical Form ◽  
Physical Composition

A series of tests are conducted to get the physical composition, physical form and the soil-water characteristic curve in different dry density of three typical composite unsaturated soils in west Sichuan. Test data shows that the variation of physical composition, particle size and dry density can result in great change of soil-water characteristic curve. The bigger the dry density is, the more hydrophilic mineral the soil has, the more gentle the soil-water characteristic curve is, and the higher its residual moisture content is. In addition, under the same water content, matrix suction decreases with less clay content and more content. For the three typical composite unsaturated soils, with relatively bigger water content, the change of soil-water characteristic curve resulting from variation of dry density is less, but with the water content getting smaller, the change becomes clearer.

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 Curve for Unsaturated Mixed-Soil Considering Physical Form and Dry Density Effect

2013 ◽  
Vol 353-356 ◽  
pp. 785-789
Author(s):  
Kai Cui ◽  
Hui Huang
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Unsaturated Soils ◽  
Characteristic Curve ◽  
Clay Content ◽  
Dry Density ◽  
Residual Moisture ◽  
Soil Water Characteristic Curve ◽  
Physical Form ◽  
Physical Composition

A test is conducted to get the soil-water characteristic curve for three typical composite unsaturated soils in west Sichuan, considering its physical composition, physical form and dry density. Test data shows that the variation of physical composition, particle size and dry density can result in great change of soil-water characteristic curve. The bigger the dry density is and the more hydrophilic mineral it has, the more gently the soil-water characteristic curve is, and the higher dry density soil sample has higher residual moisture content. In addition, matrix suction decreased with less clay content and more content under the same water content. For three typical composite unsaturated soils, the change of soil-water characteristic curve resulting from variation of dry density is less in bigger water content, and is more in lower water content.

The Experiment on Soil Water Characteristic Curve Considering the Effect of Urea Concentration

2014 ◽  
Vol 919-921 ◽  
pp. 795-799
Author(s):  
Gai Qing Dai ◽  
Dong Fang Tian ◽  
Yao Ruan ◽  
Lang Tian ◽  
You Le Wang
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Characteristic Curve ◽  
Urea Concentration ◽  
Test Method ◽  
Materials Selection ◽  
Valuable Data ◽  
Soil Water Characteristic Curve ◽  
Concentration Test ◽  
The Impact

A new soil water characteristic curve (SWCC) experiment contemplating urea concentration is presented in the paper. We focus on the impact of the SWCC considering urea concentration test method for materials selection and introduction, experimental results, and finally, we have conducted some experiments of SWCC and obtained some valuable data which could affect urea concentration. By using linear fitting, an exponential function between water content and suction and urea concentration is established.

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.

A Soil Water Characteristic Curve Model Considering Urea Concentration

2013 ◽  
Vol 798-799 ◽  
pp. 157-160
Author(s):  
You Le Wang ◽  
Dong Fang Tian ◽  
Gai Qing Dai ◽  
Yao Ruan ◽  
Lang Tian
Keyword(s):  
Experimental Data ◽  
Water Content ◽  
Soil Water ◽  
Exponential Function ◽  
Characteristic Curve ◽  
Urea Concentration ◽  
Exponential Functions ◽  
Valuable Data ◽  
Soil Water Characteristic Curve ◽  
Curve Model

A new soil water characteristic curve (SWCC) model considering urea concentration is presented in the paper. Two assumptions are used to obtain the model. One is SWCC which could be described by exponential functions in the experiments. Another is relationship between the parameters of exponential functions and urea concentration which is linear based on experimental data. In the research, we have carried out some experiments of SWCC and obtained some valuable data which could affect urea concentration. By using linear fitting, an exponential function between water content and suction and urea concentration is established.

Aggravated water deficit in the Loess Plateau of China as indicated by the soil available water content

2020 ◽  
Author(s):  
Xiao Zhang ◽  
Wenwu Zhao ◽  
Paulo Pereira
Keyword(s):  
Land Cover ◽  
Water Content ◽  
Soil Water ◽  
Water Deficit ◽  
Loess Plateau ◽  
Characteristic Curve ◽  
The Loess Plateau ◽  
Land Cover Types ◽  
Soil Water Characteristic Curve ◽  
Available Water Content

<p>The soil available water content (AWC) has a strong ability to indicate the soil water conditions under different land cover types. Although the AWC has long been calculated, soil water characteristic curve estimation models and the distribution of AWC, as well as the impact factors, have rarely been evaluated in the Loess Plateau of China. In this study, four typical land cover types were selected: introduced shrubland, introduced grassland, natural restored shrubland and natural restored grassland. Four widely used models were compared with the van Genuchten (VG) model, including the Arya and Paris (AP) model, Mohammadi and Vanclooster (MV) model, Tyler and Wheatcraft (TW) model, and linear fitting (LF) model to estimate the wilting point. The distribution of AWC and the relationships with environmental factors were measured and analyzed. The results showed the following: (1) the MV model was the most suitable model to estimate the soil water characteristic curve in the Loess Plateau; (2) the factors impacting the AWC varied under different precipitation gradients, and the area with a mean annual precipitation of 440-510 mm was the most sensitive zone to environmental and vegetation factors; and (3) the soil water deficit was more severe when considering AWC than when considering soil water content (SWC), and the water deficits were different under introduced grassland and introduced shrubland. Consequently, the construction of vegetation restoration should be more cautious and consider the trade-off between soil conservation and water conservation. During restoration, policy makers should focus on the AWC in addition to the SWC to better assess the soil moisture status.</p>

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