scholarly journals Comparison between the in situ and laboratory water retention curves for a silty sand

2010 ◽  
pp. 423-428 ◽  
Author(s):  
A Askarinejad ◽  
F Casini ◽  
P Kienzler ◽  
S Springman
Keyword(s):  
Water Retention ◽  
Silty Sand ◽  
Laboratory Water

scholarly journals Hydromechanical behaviour of a silty sand from a steep slope triggered by artificial rainfall: from unsaturated to saturated conditions

2013 ◽  
Vol 50 (1) ◽  
pp. 28-40 ◽  
Author(s):  
Francesca Casini ◽  
Victor Serri ◽  
Sarah M. Springman
Keyword(s):  
Mechanical Behaviour ◽  
Water Retention ◽  
Stress Path ◽  
Steep Slope ◽  
Silty Sand ◽  
Water Retention Curve ◽  
Retention Curve ◽  
Hydromechanical Behaviour ◽  
Water Contents

This paper presents an experimental investigation aimed at studying the hydromechanical behaviour of a silty sand from a steep slope in Ruedlingen in the northeast of Switzerland, where a landslide-triggering experiment was carried out. The hydromechanical behaviour of the statically compacted Ruedlingen silty sand has been studied under saturated and unsaturated conditions, beginning with different initial void ratios and water contents. The specimens were prepared in the laboratory using static compaction, to reproduce the mean dry density and mean water content expected in natural unsaturated in situ conditions, thus promoting specimen homogeneity and test repeatability. The choice of compaction parameters was supported by a detailed physical and microstructural investigation to produce laboratory specimens with a similar microstructure to that of the natural soil. The aim of the work was to characterize the mechanical behaviour of the soil at different gravimetric water contents in a triaxial stress path apparatus and to link the mechanical behaviour with the soil-water retention curve obtained under suction-controlled conditions with different void ratios. Soil specimens with three different gravimetric water contents were exposed to conventional isotropically consolidated drained and undrained stress paths for the water phase and to stress paths simulating in situ anisotropic compression followed by a decrease of mean effective stress at constant axial load. The radial deformation of the unsaturated specimens was measured with a laser device installed in a triaxial stress path cell. Results have been interpreted using a Bishop stress approach, evaluating the suction through the water retention curve. A simple equation has been proposed to model the compressibility behaviour of the soil tested, which depends on the parameter χ and the stress ratio η. Possible unstable response along the stress path analysed has been investigated by means of second-order work and the validity of a unified framework has also been verified under unsaturated conditions.

Gas permeability and water retention of a repacked silty sand amended with different particle sizes of peanut shell biochar

2020 ◽  
Vol 84 (5) ◽  
pp. 1630-1641
Author(s):  
Zhongkui Chen ◽  
Chaowei Chen ◽  
Viroon Kamchoom ◽  
Rui Chen
Keyword(s):  
Water Retention ◽  
Gas Permeability ◽  
Silty Sand ◽  
Particle Sizes ◽  
Peanut Shell

scholarly journals Determination of the Soil Water Retention Curve Using the Flow Pump

2015 ◽  
Vol 68 (2) ◽  
pp. 207-213
Author(s):  
Luciana Portugal Menezes ◽  
Waldyr Lopes Oliveira Filho ◽  
Cláudio Henrique Carvalho Silva
Keyword(s):  
Soil Water ◽  
Water Retention ◽  
Unsaturated Flow ◽  
Silty Sand ◽  
Water Retention Curve ◽  
Soil Water Retention Curve ◽  
Soil Water Retention ◽  
Retention Curve ◽  
Flow Problems ◽  
Flow Pump

AbstractReliable measurements of the Soil Water Retention Curve, SWRC, are necessary for solving unsaturated flow problems. In this sense, a method to obtain the SWRC of a silty sand using a flow pump, as well as details about procedures and some results, are herein presented. The overall conclusion is that the new method is very convenient, fully automated, and produces reliable results in a fast and easy way, making the technique very promising.

scholarly journals A Novel Frequency Domain Impedance Sensor with a Perforated Cylinder Coaxial Design for In-Situ Measuring Soil Matric Potential

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2626 ◽  
Author(s):  
Chao Chen ◽  
Xiaofei Yan ◽  
Qiang Xu ◽  
Song Yu ◽  
Yihan Ma ◽  
...  
Keyword(s):  
Water Content ◽  
Water Retention ◽  
Soil Samples ◽  
Environmental Research ◽  
Water Retention Curve ◽  
The Novel ◽  
Soil Matric Potential ◽  
Matric Potential ◽  
Retention Curve

Soil matric potential is an important parameter for agricultural and environmental research and applications. In this study, we developed a novel sensor to determine fast and in-situ the soil matric potential. The probe of the soil matric potential sensor comprises a perforated coaxial stainless steel cylinder filled with a porous material (gypsum). With a pre-determined gypsum water retention curve, the probe can determine the gypsum matric potential through measuring its water content. The matric potential of soil surrounding the probe is inferred by the reading of the sensor after the soil reaches a hydraulic equilibrium with the gypsum. The sensor was calibrated by determining the gypsum water retention curve using a pressure plate method and tested in three soil samples with different textures. The results showed that the novel sensor can determine the water retention curves of the three soil samples from saturated to dry when combined with a soil water content sensor. The novel sensor can respond fast to the changes of the soil matric potential due to its small volume. Future research could explore the application for agriculture field crop irrigation.

In situ modification of Nafion® membranes with phospho-silicate for improved water retention and proton conduction

2009 ◽  
Vol 333 (1-2) ◽  
pp. 50-58 ◽  
Author(s):  
Aravindaraj G. Kannan ◽  
Namita Roy Choudhury ◽  
Naba K. Dutta
Keyword(s):  
Water Retention ◽  
Proton Conduction ◽  
In Situ Modification

Design of a hierarchically structured hybrid material via in situ assembly of a silica aerogel into a wood cellular structure

RSC Advances ◽  
2016 ◽  
Vol 6 (67) ◽  
pp. 62825-62832 ◽  
Author(s):  
M. Sedighi Gilani ◽  
S. Zhao ◽  
S. Gaan ◽  
M. M. Koebel ◽  
T. Zimmermann
Keyword(s):  
Thermal Conductivity ◽  
Hybrid Material ◽  
Dimensional Stability ◽  
Silica Aerogel ◽  
Cellular Structure ◽  
Water Retention ◽  
Heat Of Combustion ◽  
Structure Modification ◽  
Reduced Water

We present a route for incorporation of silica aerogel into wood cellular structure. Modification results in an improved dimensional stability and reduced water retention of the material, with lower thermal conductivity and total heat of combustion.

scholarly journals Hydrogels Improve Plant Growth in Mars Analog Conditions

2021 ◽  
Vol 8 ◽  
Author(s):  
Frédéric Peyrusson
Keyword(s):  
Plant Growth ◽  
Food Production ◽  
Water Retention ◽  
Organic Matter Content ◽  
Matter Content ◽  
Research Station ◽  
Soil Water Retention ◽  
Mentha Spicata ◽  
Potting Medium

Sustainable human settlement on Mars will require in situ resource utilization (ISRU), the collection and utilization of Mars-based resources, including notably water and a substrate for food production. Plants will be fundamental components of future human missions to Mars, and the question of whether Mars soils can support plant growth is still open. Moreover, plant cultivation may suffer from the lack of in situ liquid water, which might constitute one of the biggest challenges for ISRU-based food production on Mars. Enhancing the crop yield with less water input and improving water utilization by plants are thus chief concern for sustainable ISRU food production. Hydrogels are polymers able to absorb large quantity of water and to increase soil water retention, plant establishment and growth. This work reports on the short-term assessment of plant growth in Mars soil analogs supplemented with hydrogels. Soil analogs consisted of sand and clay-rich material, with low organic matter content and alkaline pH. Soils were supplemented with 10% (w/w) potting medium and were sampled in Utah desert, in the vicinity of the Mars Desert Research Station, surrounded by soils sharing similarities in mineralogical and chemical composition to Martian soils. Height and dry biomass of spearmint (Mentha spicata) were compared under various irrigation frequencies, and seed germination of radish (Raphanus sativus) were monitored. Under limited irrigation, results indicate that the soil analogs were less capable of supporting plant growth as a comparison to potting medium. The effects of hydrogel supplementation were significant under limited irrigation and led to spearmint heights increased by 3 and 6% in clay- and sand-containing soils, respectively. Similarly, hydrogel supplementation resulted in spearmint mass increased by 110% in clay-containing soils and 78% in sand-containing soils. Additionally, while radish seeds failed to germinate in soil analogs, hydrogel supplementation allows for the germination of 27% of seeds, indicating that hydrogels might help loosening dense media with low water retention. Collectively, the results suggest that supplementation with hydrogel and plant growth substrate could help plants cope with limited irrigation and poor alkaline Mars soil analogs, and are discussed in the context of strategies for ISRU-based off-world colonization.

scholarly journals Swelling behavior of unsaturated claystone/ bentonite mixtures

2020 ◽  
Vol 195 ◽  
pp. 04011
Author(s):  
Marvin Middelhoff ◽  
Olivier Cuisinier ◽  
Farimah Masrouri ◽  
Jean Talandier ◽  
Nathalie Conil
Keyword(s):  
Water Retention ◽  
Experimental Program ◽  
Dry Density ◽  
Swelling Properties ◽  
Rock Formations ◽  
Backfill Materials ◽  
Retention Characteristics ◽  
Collapse Behavior ◽  
The Impact

This laboratory experimental program investigated the impact of variations in the expansive mineral content, the grain size distribution of employed bentonite, the initial dry density and the selected hydration path on the water retention characteristics and swelling properties of processed Callovo-Oxfordian claystone and its mixtures with MX80 bentonite. The French reference concept for the disposal of nuclear waste in deep sedimentary rock formations envisages the reemployment of excavated material as backfill material, which is installed in situ by means of conventional compaction techniques. The investigations were of special interest as the major issues involving in situ compacted backfill materials were portrayed. Experiments showed that the impact of variations in the dry density on the water retention characteristics of all materials vanished as suctions exceeded 100 MPa. The negligible impact of variations in the initial dry density on the collapse behavior of claystone/ bentonite mixtures remained questionable.

scholarly journals The Effect of Heterogeneity on the Distribution and Treatment of PFAS in a Complex Geologic Environment

2021 ◽  
Vol 2 ◽  
Author(s):  
Rick McGregor ◽  
Leticia Benevenuto
Keyword(s):  
Activated Carbon ◽  
Hydraulic Conductivity ◽  
Emerging Contaminants ◽  
Fractured Rock ◽  
Ion Exchange Resin ◽  
Subsequent Treatment ◽  
Silty Sand ◽  
Aquifer System ◽  
Pump And Treat

Per-and polyfluoroalkyl substances (PFAS) have been identified as emerging contaminants of concern in the environment in a wide variety of media including groundwater. Typically, PFAS-impacted groundwater is extracted by pump and treat systems and treated using sorptive media such as activated carbon and ion exchange resin. Pump and treat systems are generally considered ineffective for the remediation of dissolved phase contaminants including PFAS but instead are considered applicable for plume containment. An alternative to pump and treat is in-situ treatment. The demonstrated use of in-situ treatment for PFAS-impacted groundwater is limited with only colloidal activated carbon (CAC) being shown to effectively attenuate PFAS over short and moderate time periods. Active research topics for the in-situ treatment of PFAS include the effect of heterogeneity on the distribution of the CAC, the lifespan of the CAC itself, the effect of competitive adsorption/absorption, and the effect of other geochemical conditions on the removal process. This study looked at the effect of heterogeneity on the distribution of CAC and subsequent treatment of PFAS at a site with a multiple aquifer system. The site’s geology varied from a silty sand to sand to fractured bedrock with all three units being impacted by PFAS and benzene (B), toluene (T), ethylbenzene (E), and xylene (X). Parameters evaluated included the distribution of the CAC as well as the subsequent treatment of the PFAS and BTEX. Results of groundwater sampling indicated that the PFAS detected within the groundwater were treated effectively to below their respective reporting limits for the duration of the 1-year test in both the silty sand and sand aquifers. The PFAS in the fractured rock aquifer showed a different treatment profile with longer carbon chained PFAS being attenuated preferentially compared to the shorter carbon chained PFAS. These results suggest that competitive sorptive reactions were occurring on the CAC within the fractured rock. Analysis of the unconsolidated aquifer materials determined that direct push injection of the CAC was effective at delivering the CAC to the target injection zones with post-injection total organic carbon (TOC) concentrations increasing by up to three orders of magnitude compared to pre-injection TOC concentrations. Heterogeneity did have an impact on the CAC distribution with higher hydraulic conductivity zones receiving more CAC mass than lower hydraulic conductivity zones.

Effect of biochar type on infiltration, water retention and desiccation crack potential of a silty sand

Biochar ◽  
2020 ◽  
Vol 2 (4) ◽  
pp. 465-478
Author(s):  
Rojimul Hussain ◽  
Sanandam Bordoloi ◽  
Piyush gupta ◽  
Ankit Garg ◽  
K. Ravi ◽  
...  
Keyword(s):  
Water Retention ◽  
Silty Sand ◽  
Desiccation Crack
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