Assessment of Model Consistency for Determination of Soil–Water Characteristic Curves

Matlan

Advances in Civil Engineering

et al. 2021

Self Cite

The focus of this study was to investigate the effect of loess soil treated with lime on the lateral-seepage response. Three groups of box experiments were carried out to study the lateral-seepage effect under different types of loess-lime structures. Automated testing systems were designed to perform experiments and collect data. Additionally, numerical analysis of lateral-seepage impact and embankment settlement was performed. Finally, moisture content and settlement were monitored to quantify lateral-seepage effect results under corresponding loess-lime treatment. Results showed that loess-lime compaction piles and diaphragm wall structures could effectively prevent lateral seepage, and the latter was better. The simulated results are similar to the measured values of the box experiment, which indicates the accuracy of the simulation analysis and further supports the experimental results of this study.

Section: Introductionmentioning

confidence: 99%

Experimental and Numerical Analysis Study on Loess-Lime Structures Used for Lateral Antiseepage in Deep Collapsible Ground Embankment

Matlan

Advances in Civil Engineering

et al. 2021

Self Cite

“…In recent decades, several empirical models have been developed to predict SWCC, such as Gardner [14], Brooks Corey [15], Van Genuchten [16], and Fredlund and Xing [17], among others. Researchers have also compared and evaluated the applicability and consistency of different empirical models [18,19].…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation of the Soil-Water Characteristic Curves (SWCC) of Expansive Soil: Effects of Sand Content, Initial Saturation, and Initial Dry Unit Weight

Alnmr,

Alzawi,

Ray

et al. 2024

Water

Soil-water characteristic curve (SWCC) is an essential parameter in unsaturated soil mechanics, and it plays a significant role in geotechnical engineering to enhance theoretical analysis and numerical calculations. This study investigated the effects of key factors, such as the percentage of sand, initial degree of saturation, and initial dry unit weight, on the SWCC of expansive soil by measuring the matric suction using a pressure apparatus method. The empirical equation of SWCC was obtained using the Van Genuchten and Fredlung Xing models, and the processing of experimental data checks the fitting of the two empirical models. The findings revealed that the Fredlung Xing model fit the relationship between matric suction and volumetric water content of expansive soil better than the Van Genuchten model, indicating that the pressure apparatus approach’s experimental data are correct and acceptable. The study also found that the matric suction increased with decreasing percentage of added sand at the same volumetric moisture content, and the increase in initial dry unit weight increased the matric suction, with the water retention capacity decreasing significantly after adding 20% sand. Moreover, as the initial degree of saturation increased, the volumetric water content decreased, and the characteristic curves became identical when the initial saturation degree reached 90%. Finally, to minimize the water retention capacity of expansive soils, the study recommended adding a percentage of sand not less than 30% to the expansive clay sample.

“…There are many instruments available for measuring the matric suction, such as the Tensiometer Method (Marinho et al, 2008), Pressure apparatus (Bechtold et al, 2018;Jiang et al, 2020), Electrical resistance blocks (Zeitoun et al, 2021), etc., and indirect methods, such as the Filter paper-based method (Mahler and Mendes, 2005;Fattah et al, 2021), Empirical method (Kern, 1995), etc. During the past few decades, many empirical models have been developed to predict SWCC, such as the Van-Genuechten (1980), Brooks-Corey (1964), Fredlund and Xing (1994), Gardner (1958), etc., and researchers also compared and evaluated the applicability and consistency of various empirical models (Matlan et al, 2015;Fattah et al, 2021). Based on this, the scholars investigated the SWCC of clay (Tripathy et al, 2014;Li et al, 2017), sand (Yan and Zhang, 2015), and expansive soil (Tamer et al, 2017;Ahmed et al, 2018), and they analyzed the effect of dry density (Birle et al, 2008;Gallage and Uchimura, 2010), void ratio (Heshmati and Motahari, 2015), grain size distribution (Chen et al, 2018;Zhai et al, 2020), and temperature (ElKeshky, 2011;Qiao et al, 2019) on the SWCC.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on the Effect of Key Factors on the Soil–Water Characteristic Curves of Fine-Grained Tailings

Cao

Tian

Gui

et al. 2021

Front. Environ. Sci.

The soil–water characteristic curve (SWCC) is an essential parameter for studying the mechanical properties of unsaturated tailings, and it plays an important role in stability assessment and prediction of unsaturated tailings dams. In this paper, the matrix suction was measured indirectly by a filter paper-based method to investigate the effects of key factors (gradation, temperature, and initial dry density) on the soil–water characteristic curves of fine-grained tailings, and the Van Genuchten model was adopted to obtain the empirical equation of SWCC and to verify the accuracy of experimental results. The results showed the following: 1) the Van Genuchten model fits well the relationship between matric suction and volumetric moisture content of fine-grained tailings, indicating that experimental data determined by filter paper-based method is accurate and appropriate; 2) at the same volumetric moisture content, the matrix suction increased with decreasing average particle size, and the decrease in temperature will increase the matrix suction and water-holding capacity of fine-grained tailings, and the matrix suction of the tailings in summer is 38.3% lower than that in winter under the natural volumetric moisture content (14.0%); 3) when the saturation degree of fine-grained tailings is less than 60%, the greater the initial dry density, the better the water-holding capacity and matrix suction.