scholarly journals Experimental Study of Bearing Capacity Effect in Swelling Soil

2021 ◽  
Vol 26 (4) ◽  
pp. 167-178
Author(s):  
A.N. Mohammed ◽  
A.A. Khalil
Keyword(s):  
Bearing Capacity ◽  
Water Content ◽  
Pressure Effect ◽  
Swelling Pressure ◽  
Shear Resistance ◽  
Unit Weight ◽  
Dry Unit Weight ◽  
Swelling Soil ◽  
Natural Water Content ◽  
Swell Pressure

Abstract The current study aims to investigate the effects of swell pressure on the bearing capacity of swelling soil. A model and some laboratory tests have been created to investigate the swell pressure effect on the bearing capacity variation of soil swelling due to swelling pressure. The influence of varying water content w/c and dry unit weight (γ d ) on the shear strength and swelling pressure was studied. The soil has been taken from Diwan Residential Compound-Mosul. It is classified as highly swelling soil. The swell pressure of soils at their natural water content reached 385 kN / m2 . Experiment results show that the parameters of shear resistance decreased with the w/c increase at the constant value of (γ d ), increased with the (γd ) increase when the w/c was constant. Results show that the swelling pressure decreased with the w/c increase, while it increased with the (γ d ) increase. Also, the results obtained using was model show that the resistance of bearing capacity of pre-saturated selected soil was 196 kN / m 2, while the bearing capacity was 620kN / m 2 when taking into account in the generation of swelling pressure.

scholarly journals Forensic Evaluation of Compacted Soils using RAMCODES

2018 ◽  
Vol 4 (10) ◽  
pp. 2275 ◽  
Author(s):  
Romer D. Oyola-Guzmán ◽  
Rómulo Oyola-Morales
Keyword(s):  
Bearing Capacity ◽  
Water Content ◽  
Unit Weight ◽  
Strength Analysis ◽  
Construction Site ◽  
Compacted Soils ◽  
Compacted Soil ◽  
Dry Unit Weight ◽  
Heavy Equipment ◽  
Proctor Test

Unexpected failure of compacted soils was explained using design curves of the Rational Methodology for Compacted Geomaterial’s Density and Strength Analysis (RAMCODES).  Forensic geotechnical evaluation, applied to a compacted soil used at a construction site, demonstrated that the bearing capacity of the soil was influenced by the water content and the dry unit weight. At the construction site, the only criterion used for quality control of the compacted soil was the minimum compaction percentage; the maximum dry unit weight (achieved using the standard Proctor test) was used when the soil was compacted with light equipment, and the maximum dry unit weight (achieved using the modified Proctor test) was used when it was compacted with heavy equipment. After changing water content conditions, the soil compacted with heavy equipment and the soil compacted with light equipment exhibited changes in bearing capacity; the soil compacted with light equipment showed a failure, whereas the soil compacted with heavy equipment did not. The causes of failure were evaluated from samples of soil analyzed in the laboratory; analysis was performed using design curves obtained through a factorial experimental design. Our analysis revealed that the criterion of minimum compaction percentage was not adequate to determine the actual mechanical performance of the soil. We sought to determine why the soil compacted with light equipment did not satisfy the bearing capacity expected after compaction, and what other actions should performed at a construction site to avoid failure of soils compacted with light equipment. 

scholarly journals Evaluations of the effects of soil properties and electrical conductivity on the water content reflectometer calibration for landfill cover soils

2017 ◽  
Vol 12 (No. 1) ◽  
pp. 10-17 ◽  
Author(s):  
K. Kim ◽  
J. Sim ◽  
T.-H. Kim
Keyword(s):  
Electrical Conductivity ◽  
Soil Properties ◽  
Water Content ◽  
Clay Content ◽  
Liquid Limit ◽  
Time Domain Reflectometry ◽  
Volumetric Water Content ◽  
Unit Weight ◽  
Landfill Cover ◽  
Dry Unit Weight

This study presents soil-moisture calibrations using low-frequency (15–40 MHz) time domain reflectometry (TDR) probe, referred to as water content reflectometer (WCR), for measuring the volumetric water content of landfill cover soils, developing calibrations for 28 different soils, and evaluating how WCR calibrations are affected by soil properties and electrical conductivity. A 150-mm-diameter PVC cell was used for the initial WCR calibration. Linear and polynomial calibrations were developed for each soil. Although the correlation coefficients (R<sup>2</sup>) for the polynomial calibration are slightly higher, the linear calibrations are accurate and pragmatic to use. The effects of soil electrical conductivity and index properties were investigated using the slopes of linear WCR calibrations. Soils with higher electrical conductivity had lower calibration slopes due to greater attenuation of the signal during transmission in the soil. Soils with higher electrical conductivity tended to have higher clay content, organic matter, liquid limit, and plasticity index. The effects of temperature and dry unit weight on WCR calibrations were assessed in clayey and silty soils. The sensor period was found to increase with the temperature and density increase, with greater sensitivity in fine-textured plastic soils. For typical variations in temperature, errors in volumetric water content on the order of 0.04 can be expected for wet soils and 0.01 for drier soils if temperature corrections are not applied. Errors on the order of 0.03 (clays) and 0.01 (silts) can be expected for typical variations in dry unit weight (± 2 kN/m<sup>3</sup>).

Compressive strength behavior of fine-grained frozen soils

1990 ◽  
Vol 27 (4) ◽  
pp. 472-483 ◽  
Author(s):  
Harsha Wijeweera ◽  
Ramesh C. Joshi
Keyword(s):  
Compressive Strength ◽  
Water Content ◽  
Yield Stress ◽  
Constant Strain Rate ◽  
Unit Weight ◽  
Total Water Content ◽  
Total Water ◽  
Frozen Soils ◽  
Fine Grained ◽  
Dry Unit Weight

Constant strain-rate (0.01/s) uniaxial compression-strength tests were conducted on more than 200 saturated samples of six fine-grained frozen soils at temperatures between −5 and −17 °C. Saturated soil samples containing total water contents between 15% and 105% were prepared using a consolidation apparatus specially designed for this purpose. The effect of dry unit weight, total water content, temperature, and soil type on the behavior of peak compressive strength was studied. Test results indicate the peak compressive strength of fine-grained soils is sensitive to changes in the dry unit weight and the total water content. The temperature dependence of the peak compressive strength is represented by a simple power law. An empirical formula has been developed to predict the peak compressive strength of fine-grained frozen soils at a particular temperature using index properties, specific surface area, particle-size distribution, and dry unit weight. A linear relationship exists between the peak compressive stress and the yield stress. Key words: peak compressive strength, yield stress, frozen soils, fine-grained soils, dry unit weight, failure strain, temperature, total water content, slurry consolidation.

scholarly journals Geotechnical Properties of Soft Marine Soil at Chan May Port, Vietnam

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Thi Nu NGUYEN ◽  
Thanh Duong NGUYEN ◽  
Truong Son BUI
Keyword(s):  
Shear Strength ◽  
Water Content ◽  
Void Ratio ◽  
Soft Soil ◽  
Field Investigation ◽  
Liquid Limit ◽  
Geotechnical Properties ◽  
Unit Weight ◽  
Dry Unit Weight ◽  
Marine Soil

Soft marine soil deposit is distributed under the sea with many special properties. This type ofsoil is rarely researched in Vietnam because of the difficult geotechnical investigation under the sea level.In this paper, the experimental laboratories were performed to investigate the geotechnical properties ofsoft marine soil at Chan May port, Vietnam. The field investigation results indicate that the thickness ofsoft soil varies from a few meters to more than ten meters. Soft soil has a high value of water content,void ratio, and compressibility and a low value of shear strength. The compression index has a goodrelationship with water content, liquid limit, and dry unit weight. The unit weight, shear strength, and preconsolidationpressure increase with the increase of depth. These results show that the soil in the studyarea is unfavorable for construction activities.

Effect of Heating Borehole Spacing on Plasticity of Expansive Soil

2020 ◽  
Vol 38 (7A) ◽  
pp. 1062-1068
Author(s):  
Falah H. Rahil ◽  
Husam H. Baqir ◽  
Nabeel J. Tumma
Keyword(s):  
Water Content ◽  
Representative Sample ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Heating System ◽  
Unit Weight ◽  
Initial Water Content ◽  
Initial Water ◽  
Dry Unit Weight ◽  
Laboratory Models

This paper presents the effect of spacing between boreholes heating on plasticity of expansive soils. The expansive soils used were prepared artificially by mixing Kut clay with different percentages of bentonite. Nine laboratory models of expansive soils having dry unit weight of 17.8 kN/m3 with 6% initial water content were prepared inside a steel box of (300 mm × 300 mm × 400 mm height).  A special heating system generates 400 Co for six hours was designed and manufactured for this purpose using 12 mm diameter electric heaters inserted through boreholes. Square pattern boreholes of 170 mm length with spacing (4.16d, 6.25d and 8.33d) were used. A representative sample were taken after heating from the center of the square pattern for measuring the plasticity of the soils. The results showed that the plasticity index remarkedly decreases compared with that before heating and increases with increasing bentonite and the spacing. It is also indicated that an expansive soil could be changed from high to low plasticity

scholarly journals Investigation of effect of water content on railway granular supplementary layers

2021 ◽  
pp. 64-68
Author(s):  
S Fischer
Keyword(s):  
Bearing Capacity ◽  
Water Content ◽  
Road Construction ◽  
High Water ◽  
Shear Resistance ◽  
The Other ◽  
High Water Content ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Rock Mining

Purpose. To determine the relationship between water content of continuously graded granular supplementary layers for railway substructure and their inner shear resistance and load bearing capacity. Methodology. Four different samples were produced as standard granular products from andesite. Two of them are common base courses for road construction in Hungary, the other two are common railway supplementary layers. The author performed laboratory measurements (multi-level shear box tests) that are adequate for the evaluation of inner shear resistance. The measurements of load bearing capacity and Proctor tests were executed in the laboratory of Colas Hungaria Ltd. The author performed measurements with the optimal water content values of each sample, as well as lower and higher values than them. This can show how the given granular material is sensible to the change of water content. Findings. It was proved that the granular supplementary layers, which are standardized products in road construction (as base courses), also seems to be adequate in railway construction; they are not so sensible to the variation of their water content. It does not mean that the other two granular layers are not adequate for railway substructures, but the application of road products have to be considered as substitute products. Originality. The author tried to emphasize the adequacy of rock mining for construction of ballasted railway tracks, as well as the optimal use of mineral wealth in every country with its results. Practical value. The obtained results of the present paper can be useful in the area of rock mining, and railway infrastructure engineering. During construction procedures the optimal water content values should be taken into considerations for compaction to be able to reach maximal compactness (density), but too high water content has to be avoided, which is based on the results. They can be also considered in the design phase.

EXPERIMENTAL EVALUATION OF SOIL REINFORCEMENTS IN UNPAVED ROAD

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Nahla Salim
Keyword(s):  
Bearing Capacity ◽  
Static Load ◽  
Sandy Soils ◽  
Crushed Stone ◽  
Unit Weight ◽  
Harmonic Load ◽  
Geogrid Reinforcement ◽  
Dry Unit Weight ◽  
Load Tests ◽  
Number Of Cycles

In this study, a series of 24 laboratory tests were conducted on a footing resting on crushed stone with 17.68 kN/m3 dry unit weight overlying sandy soils of two relative densities corresponding to (60% and 80%). The subbase layer is of crushed stone with a thickness of 5, 7.5 and 10 cm. Ten tests were conducted under static load with and without geogrid. All the other 14 model tests were carried out under harmonic load which was applied in a sequence determined prior (40% of static load). Tests were conducted at (2) Hz frequency according to the loading value. The process of the loading was continued until the number of cycles reached 104. The results indicated that, for static load and with the inclusion of the geogrid, as the thickness of the subbase layer increases, the percentage of increase in bearing capacity was reduced. In general, using geogrid reinforcement with subbase thickness of 7.5 and 5 cm causes an increase in bearing capacity approximately 1.5 to 2 times greater than for unreinforced respectively. This means that by using geogrid reinforcement, the thickness of subbase can be reduced which causes a reduction in construction cost.

scholarly journals Empirical Correlations for the Swelling Pressure of Expansive Clays in the City of Barranquilla, Colombia

2017 ◽  
Vol 21 (1) ◽  
pp. 45 ◽  
Author(s):  
Victor Cantillo ◽  
Vicente Mercado ◽  
César Pájaro
Keyword(s):  
Water Content ◽  
Statistical Significance ◽  
Swelling Pressure ◽  
Technical Note ◽  
Atterberg Limits ◽  
Empirical Correlations ◽  
Expansive Clays ◽  
Swelling Clays ◽  
The City ◽  
Swell Pressure

Swelling behavior of clays is of great importance for numerous engineering applications due to the prevalence of expansive clays around the world. Expansive clays are present in Mexico City, United States, Australia, Africa and South America, among others. In some cases, these types of clays could present swell pressure values greater than 400 kPa. In this technical note, correlation equations are developed to estimate the swell pressure of clays using laboratory tests performed on swelling clays in the city of Barranquilla, Colombia. Correlations are based on Atterberg limits and water content among other soil properties. Equations with statistically significant coefficients were selected and compared with equations found in the literature. Developed correlations evidenced that swell pressure decays quickly as water content increases. It was found that for the studied soils, Atterberg Limits did not present statistical significance in the estimation of swell pressure. Correlaciones empíricas para la determinación de la presión de expansión de arcillas expansivas en Barranquilla, Colombia ResumenEl comportamiento expansivo de las arcillas presenta vital importancia alrededor del mundo, ya que este tipo de arcillas se encuentras en diversas y extensas zonas del planeta. Arcillas con este tipo de comportamiento se encuentran presentes en diversas regiones del mundo como la ciudad de México, los Estados Unidos, Australia, algunas zonas de África y Sudamérica, entre otras. Este tipo de arcillas pueden presentar en algunos casos presiones de expansión superiores a los 400 kPa. En la presente nota técnica se desarrollan correlaciones para estimar la presión de expansión de arcillas con base en ensayos de laboratorio practicados a arcillas con comportamiento expansivo presentes en la ciudad de Barranquilla, Colombia. Las correlaciones desarrolladas se basan en los límites de Atterberg y contenido de humedad, entre otras propiedades de los suelos. Se seleccionaron aquellas ecuaciones que presentaban coeficientes estadísticamente significativos y se realizaron comparaciones con correlaciones presentes en la literatura. Las correlaciones mostraron que la presión de expansión decae rápidamente a medida que el contenido de humedad aumenta. Además, se observó que para los suelos estudiados los límites de Atterberg no son estadísticamente significativos para la estimación de la presión de expansión.

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