The Freezing Characteristic Curve of a Coarse-Grained Volcanic Soil

Author(s):  
Junping Ren ◽  
Shoulong Zhang ◽  
Tatsuya Ishikawa ◽  
Sai K. Vanapalli
2021 ◽  
Vol 337 ◽  
pp. 02004
Author(s):  
Sebastian Sepulveda-Cano ◽  
Edwin F. Garcia-Aristizabal ◽  
Carlos A. Vega-Posada

This work aims to numerically study the desaturation process in a coarse-grained sandy deposit by means of air injection. It is well-known that the soil cyclic strength to liquefaction of a saturated, sandy deposit is positively affected by the presence of gas in the void space in either a dissolved or a free form. A numerical study is performed to investigate some of the factors affecting the desaturation advance and controlling the soil desaturation process by air injection. Among these factors are: a) soil-water characteristic curve and intrinsic permeability (hydraulic parameters), b) injection time, and c) standard approach to two injection wells placement. Only the standard mechanisms of biphasic flow are investigated (i.e., incompressible and isothermal biphasic flow in an isotropic homogeneous porous media with capillary effects).


2013 ◽  
Vol 838-841 ◽  
pp. 1785-1790
Author(s):  
Qing Hua Jiang ◽  
Chen Xiang Yu

As a problematic material, fine grained tailings have many particular engineering characteristics and seriously affect the safety and stability of the tailing dam body. These engineering properties are closely related to moisture migration and soil suction under different water content. This article chose fine grained tailings of Li Tie Lan Ting tailings dam in Zhejiang province as an example, and measured the soil water characteristic curve (SWCC) of fine grained tailings with different partical size composition and dry density using vapour equilibrium technique. Efforts have also been made to demonstrate the influences of soil type, dry density on water retention. The study result shows that particle-size composition has a significant impact on SWCCs of the tailings. Finer grained samples have lower water loss rate and higher water-holding capacity than coarse grained samples in the same suction state. Contrary with low suction stage, dry density has negligible influence on the soil suction, and parameters effect SWCCs at high suction stage. The research results may provide a theoretical support and a beneficial reference for further research of fine grained tailingss engineering properties.


2021 ◽  
Vol 51 (1) ◽  
pp. 20210049
Author(s):  
Junping Ren ◽  
Shoulong Zhang ◽  
Chong Wang ◽  
Tatsuya Ishikawa ◽  
Sai K. Vanapalli

2005 ◽  
Vol 42 (1) ◽  
pp. 252-262 ◽  
Author(s):  
Jeff R Reinson ◽  
Delwyn G Fredlund ◽  
G Ward Wilson

Design of effective capillary barrier systems requires a thorough understanding of the soil–water interactions that take place in both coarse- and fine-grained unsaturated soils. Experimental observations of water flow through coarse porous media are presented to gain greater understanding of the processes and mechanisms that contribute to the movement and retention of water in coarse-grained unsaturated soils. The use of pendular ring theory to describe how water is held within a porous material with relatively low volumetric water contents is explored. Experimental measurements of seepage velocity and volumetric water content were obtained for columns of 12 mm glass beads using digital videography to capture the movement of a dye tracer front at several infiltration rates. An estimated curve for hydraulic conductivity versus matric suction is shown and compared to a theoretical curve. The method is shown to provide a reasonable predictive tool.Key words: soil-water characteristic curve, hydraulic conductivity curve, water permeability function, capillary barrier, matric suction.


2021 ◽  
Vol 337 ◽  
pp. 02010
Author(s):  
Roberto Alves ◽  
Gilson de F.N. Gitirana ◽  
Sai K. Vanapalli

The particle-size distribution (PSD) is the key information required by several models for prediction of the soil-water characteristic curve (SWCC). The performance of these models has been extensively investigated in the literature; however, limited studies have been undertaken with respect to the uncertainty associated with the SWCC predictions resulting from the variability in the PSD. This study aims to investigate the influence of the variability of the PSD in the prediction of SWCCs using five different models applied to three different glass beads (GBs). The PSD curves were determined by sieve analysis, laser diffraction, and image analysis. The various testing procedures were statistically evaluated to understand the influence of variability of the PSD in terms of the coefficient of uniformity (CU) and de size of particles corresponding to 10% in the PSD (D10). For each prediction model, a combination of PSD curves and their coefficient of variation were used to estimate the SWCCs. Both the CU and D10 proved to have a strong relationship with the predicted SWCCs. The CU appears to influence more the residual suction prediction while the D10 seems to have a major role for the transition and residual stages.


UKaRsT ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 33
Author(s):  
Arlita Mey Hapsari ◽  
Dian Sisinggih ◽  
Andre Primantyo Hendrawan ◽  
Sri Wahyuni

Kali Putih River is a river that is often affected by the eruption of Mount Kelud. The resulting large deposits of volcanic sand materials cause exploitation through uncontrolled sand mines. This will have an impact on potential hazards caused by environmental damage; for example, there have been several cases of riverbank landslides. Based on previous studies, it is important to study the identification of physical characteristics and mineralogy of riverbank materials through laboratory testing. The Gs value was found to be within 2.650-2.697, which can be classified as gravel or sand. According to the AASHTO standard, the classification is coarse-grained soil. By USCS classification, all samples were determined as well-graded sand. Based on the JGS standard, these samples can be classified as Volcanic Soil (VS) and Volcanic Sand (SV). SEM results showed that the grain samples had low sphericity with angular to sub-angular and a bladed-oblate granular form. From X-RD analysis, the mineral composition of samples was dominated by anorthite (CaAl2Si2O8) and albite (Na(AlSi3O8)). Associated with Bowen's Reaction, these compounds are common in young materials when the weathering process is still progressing.


10.14311/588 ◽  
2004 ◽  
Vol 44 (4) ◽  
Author(s):  
A. Farouk ◽  
L. Lamboj ◽  
J. Kos

The objective of this research is to introduce a numerical simulation model to predict approximate values of the matric suction inside unsaturated soils that have low water contents. The proposed model can be used to predict the relationship between the water content and the matric suction of a studied soil to construct the soil-water characteristic curve. In addition, the model can be utilized to combine the predicted matric suction with the soil parameters obtained experimentally, which enables us to explain how matric suction can affect the behaviour of unsaturated soils, without the need to utilize advanced measuring devices or special testing techniques. The model has given good results, especially when studying coarse-grained soils.


1996 ◽  
Vol 33 (4) ◽  
pp. 595-609 ◽  
Author(s):  
Julian K-M Gan ◽  
D G Fredlund

The saturated and unsaturated shear strength behavior of an undisturbed, completely decomposed fine ash tuff and an undisturbed, completely decomposed granite from Hong Kong were studied using direct shear and triaxial tests. The completely decomposed fine ash tuff is a fine- to medium-grained saprolite. The completely decomposed granite is a coarse-grained saprolite. Results show that matric suction increases the shear strength of both soils. The extent of the increase is the shear strength with matric suction is related to the soil-water characteristic curve for the soil and to the amount of dilation during shear. The effect of matric suction on the shear strength was more pronounced for the fine- to medium-grained completely decomposed fine ash tuff than for the coarse-grained completely decomposed granite. These studies on the saprolitic soils provide insight into the understanding of the shear strength of unsaturated, coarse-grained soils. Key words: saprolites, shear strength, matric suction, triaxial, direct shear, coarse-grained soils.


Sign in / Sign up

Export Citation Format

Share Document