Influence of the Range of Suction Measurement on the Soil Suction-Water Content Relationship

An investigation was conducted to determine the effects of temperature, compaction water content, and compaction efforts on soil suction of two expansive subgrade soils. For this purpose, two expansive soils were statically compacted at target water contents ranging from 5% to 20%. This made it possible to explore a broad spectrum of compaction conditions. Filter paper method and thermocouple psychrometer were used to measure soil suction at temperatures ranging from 10°C to 60°C. Experimental results show that compaction water content, compaction effort, and temperature have influences on soil suction. As water content increases, the influences of compaction effort and temperature on suction become less significant. Finally multiple regression formulations for predicting the soil suction of as-compacted clayey soil were established.

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Variation of Initial Soil Suction with Compaction Conditions for Clayey Soils

Journal of Mechanics ◽

10.1017/jmech.2012.52 ◽

2012 ◽

Vol 28 (3) ◽

pp. 431-437 ◽

Cited By ~ 4

Author(s):

S.-R. Yang ◽

H.-D. Lin ◽

W.-H. Huang

Keyword(s):

Water Content ◽

Clay Fraction ◽

Degree Of Saturation ◽

Soil Suction ◽

Clayey Soils ◽

Test Results ◽

Wide Range ◽

Initial Soil ◽

Compaction Energy ◽

The Relationship

AbstractIn this study, the initial soil suction of as-compacted clayey soils was evaluated for various compaction conditions, covering a wide range of compaction energy and molding water content. The soil specimens were prepared by impact compaction under three levels of compaction energy. The filter paper method was used to measure the initial soil suction of as-compacted specimens. Test results indicate that the relationship between the soil suction and the molding water content is bilinear under three different compaction energies. However, the effect of compaction energy on soil suction is different for the soils with different amounts of clay fraction and is elucidated by the macro soil properties. The change of soil suction due to different compaction energies can be predicted by the void ratio and the degree of saturation.

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RELATIONSHIPS BETWEEN THE LEAF WATER STATUS OF BARLEY AND SOIL WATER

Canadian Journal of Plant Science ◽

10.4141/cjps70-070 ◽

1970 ◽

Vol 50 (4) ◽

pp. 363-370 ◽

Cited By ~ 4

Author(s):

AGUSTIN A. MILLAR ◽

MURRAY E. DUYSEN ◽

ENOCH B. NORUM

Keyword(s):

Water Potential ◽

Water Content ◽

Soil Water ◽

Relative Water Content ◽

Soil Suction ◽

Soil Matric Potential ◽

Pressure Potential ◽

Matric Potential ◽

Relative Water ◽

Leaf Relative Water Content

Total water potential of barley (Hordeum vulgare L.) leaves from plants grown under greenhouse and growth chamber conditions was divided into pressure and osmotic potential components, and their relationship to leaf relative water content was determined. Pressure potential approached zero at a water potential of about −32 bars, and a relative water content of about 65%. A change in the elasticity of leaves occurred at about 2 bars pressure potential and about −12 bars water potential. First visible wilting was observed between 75 and 80% relative water content. Transpiration decreased as leaf relative water content decreased but transpiration was independent of soil water content until about 16% (0.6 bar soil suction). First visible wilting of barley leaves was observed at soil water content between 9 and 13% (1–5 bars soil suction). Water potential and leaf relative water content decreased as the soil matric potential decreased. There was a shift to lower relative water content and water potential values as plants became older when the soil matric potential decreased.

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Estimating soil suction from electrical resistivity

Natural Hazards and Earth System Science ◽

10.5194/nhess-13-2369-2013 ◽

2013 ◽

Vol 13 (9) ◽

pp. 2369-2379 ◽

Cited By ~ 13

Author(s):

E. Piegari ◽

R. Di Maio

Keyword(s):

Electrical Resistivity ◽

Water Content ◽

Southern Italy ◽

Geophysical Methods ◽

Matric Suction ◽

High Potential ◽

Soil Suction ◽

Explosive Activity ◽

Small Areas ◽

Soil Stress

Abstract. Soil suction and resistivity strongly depend on the degree of soil saturation and, therefore, both are used for estimating water content variations. The main difference between them is that soil suction is measured using tensiometers, which give point information, while resistivity is obtained by tomography surveys, which provide distributions of resistivity values in large volumes, although with less accuracy. In this paper, we have related soil suction to electrical resistivity with the aim of obtaining information about soil suction changes in large volumes, and not only for small areas around soil suction probes. We derived analytical relationships between soil matric suction and electrical resistivity by combining the empirical laws of van Genuchten and Archie. The obtained relationships were used to evaluate maps of soil suction values in different ashy layers originating in the explosive activity of the Mt Somma-Vesuvius volcano (southern Italy). Our findings provided a further example of the high potential of geophysical methods in contributing to more effective monitoring of soil stress conditions; this is of primary importance in areas where rainfall-induced landslides occur periodically.

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Time-dependent collapse potential of unsaturated collapsible gypseous soils

World Journal of Engineering ◽

10.1108/wje-09-2019-0276 ◽

2020 ◽

Vol 17 (2) ◽

pp. 283-294

Author(s):

Mohammed Y. Fattah ◽

Basma A. Dawood

Keyword(s):

Water Content ◽

Large Scale ◽

Void Ratio ◽

Scale Model ◽

Soil Suction ◽

Content Type ◽

Collapse Potential ◽

Time Stress ◽

Large Scale Model ◽

Gypsum Content

Purpose This study aims to predict the volume changes and collapse potential (CP) associated with the changes in soil suction by using the pressure cell and the effect of initial load on soil suction. Three types of gypseous soils have been experimented in this study, sandy gypseous soil from different parts of Iraq. A series of collapse tests were carried out using the oedometer device [single oedometer test (SOT) and double oedometer test (DOT)]. In addition, large-scale model with soil dimensions 700 × 700 × 600 mm was used to show the effect of water content changes in different relations (collapse with time, stress with time, suction with time, etc.). Design/methodology/approach A series of collapse tests were carried out using the oedometer device (SOT and DOT). In addition, a large-scale model with soil dimensions 700 × 700 × 600 mm was used to show the effect of water content changes in different relations (collapse with time, stress with time, suction with time, etc.). Findings The CP increases with the increasing of the void ratio for each soil. For each soil, the CP decreased when the initial degree of saturation increased. Kerbala soil with gypsum content (30%) revealed collapse value higher than Tikrit soil with gypsum content (55%) under the same initial conditions of water content and density, this is because the higher the Cu value of Kerbala soil is, the more well-graded the soil will be. Upon wetting, the smaller particles or fractions of the well-graded soil tend to fill in the existing voids, resulting in a lower void ratio as compared to the poorly graded one. Consequently, soils with high Cu value tend to collapse more than poorly graded ones. The compressibility of the soil is low when loaded under unsaturated condition, the CP for samples tested in the DOTs under stress level 800 kPa are greater than those obtained from collapse test at a stress level of 200 kPa. Originality/value The initial value of suction for all soils increases with initial water content decreases.

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Evaluation of time response of GMS for soil suction measurement

MATEC Web of Conferences ◽

10.1051/matecconf/202133701014 ◽

2021 ◽

Vol 337 ◽

pp. 01014

Author(s):

Danilo L. Vettorello ◽

Fernando A. M. Marinho

Keyword(s):

Water Content ◽

Indirect Method ◽

Civil Engineering ◽

Time Response ◽

Engineering Practice ◽

Soil Suction ◽

Residual Soil ◽

Content Variation ◽

Granular Matrix ◽

Matrix Sensor

The Granular Matrix Sensor (GMS) is an indirect method for soil suction measurement. Since GMS is comparatively inexpensive, robust and usually provide continuous soil suction data, it is a natural candidate for civil engineering practice. The sensor has been used mainly for irrigation purposes, and also for some civil engineering activities. Questions about its effectiveness and reliability are still posed, making studies about this topic desirable. This study presents a laboratory comparison between Watermark and an ordinary tensiometer during an equilibrium period and for a wetting procedure performed in a compacted sandy silt soil (residual soil of gneiss). The results yielded that GMS may provide tensiometer equivalent suction values in a context of no significant water content variation. However, it takes a longer time to obtain stabilized suction values. During the wetting procedure, GMS presented a delay of about 2 h in detecting water while tensiometer detection was almost instantaneous.

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A General Discussion of Soil-Water Interaction in Expansive Soil

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.368-370.1591 ◽

2013 ◽

Vol 368-370 ◽

pp. 1591-1595

Author(s):

Y.Y. Zhou ◽

Feng Hua Zhao ◽

Wei Cheng Shi ◽

Jie Li

Keyword(s):

Water Content ◽

Soil Water ◽

Effective Stress ◽

Characteristic Curve ◽

Expansive Soil ◽

Soil Suction ◽

Soil Behavior ◽

Soil Covers ◽

Water Interaction ◽

Soil Settlement

In Australia, the distortions of light structures in expansive soil are widely reported, often such damages are due to the soil settlement caused by expansive soil swelling and shrinkage. Expansive soil covers large areas of land in this country and its behavior is complicated. Generally the expansive soil behavior is closely related with the water content. This paper gives a preliminary discussion of soil-water interaction in expansive soil in three aspects: effective stress, soil suction profile and soil water characteristic curve (SWCC). Hopefully the investigation can help making the engineering guideline in real construction.

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A Theoretical Study of Some Unsaturated Properties for Different Soils

Journal of University of Babylon for Engineering Sciences ◽

10.29196/jubes.v26i9.1720 ◽

2018 ◽

Vol 26 (9) ◽

pp. 149-165

Author(s):

Mohammed Nawaf Jirjees Alzaidy

Keyword(s):

Shear Strength ◽

Hydraulic Conductivity ◽

Water Content ◽

Unsaturated Soil ◽

Basic Relation ◽

Soil Suction ◽

Unsaturated Hydraulic Conductivity ◽

Clayey Silt ◽

Two Parameters ◽

Different Soils

Soil–water characteristic curves (SWCC) can be defined as the relationship between the water content and suction of an unsaturated soil. It considered a basic relation to explanation of the engineering behaviour of unsaturated soil such as hydraulic conductivity and shear strength, So the study of SWCC is useful to reduce the time and cost of unsaturated soil testing for different engineering purposes. An approach model has been used to predict the SWCC for different soils. The influence of the soils on SWCC shape, the unsaturated hydraulic conductivity and shear strength parameters have been studied in this paper using mathematical models. The results of SWCC show that suction of clay soil is bigger than sandy soil, while the clayey silt soils exhibit an intermediate behaviour at same water content. The values of unsaturated shear strength are increasing while the unsaturated hydraulic conductivity is decreasing with increasing soil suction. This behaviour of the last two parameters with soil suction should be taken in consideration for engineering purposes.

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Soil cracking propagation due to dryness and its relation to suction

MATEC Web of Conferences ◽

10.1051/matecconf/202133701021 ◽

2021 ◽

Vol 337 ◽

pp. 01021

Author(s):

Elisangela do Prado Oliveira ◽

Karoline Soecki ◽

Vitor Pereira Faro ◽

Alessander Christopher Morales Kormann

Keyword(s):

Intensity Factor ◽

Water Content ◽

Soil Water ◽

Hydraulic Properties ◽

Clay Content ◽

Water Infiltration ◽

Soil Suction ◽

Weather Variables ◽

Hydraulic Behaviour ◽

Soil Cracks

Investigation of Crack Intensity Factor is essential as it affects the mechanical and hydraulic behaviour of soils. Soil water coming from the wet seasons or from the water table, is removed by evaporation during the driest season. The loss of water provokes a significant increase in suction. When it exceeds the tensile strength of the soil, cracks occur that can modify the mechanical and mainly hydraulic properties of the soil, creating preferred paths for water infiltration. Little research is conducted on quantifying cracking in soil relating it to its hydraulic properties. This research aims to investigate the cracking of soils with focus on analysing its relation to water content and soil suction. Soils from a specific region in Brazil with clay predominance are collected and characterized. Unsaturated soil specimens are prepared and subjected to environmental real conditions in order to progressively check the consequences caused by the environment in soils with different clay content during four weeks. The Crack Intensity Factor is measured along the time through image processing. The water content is monitored through volume water content sensors. The measured results are evaluated to correlate crack intensity factor as function of weather variables and soil water content.

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