A comparison between undrained shear strength of clayey soils acquired by “PMT” and laboratory tests

2020 ◽  
Vol 13 (14) ◽  
Author(s):  
Akbar Cheshomi ◽  
Ehsan Bakhtiyari ◽  
Hadi Khabbaz
Keyword(s):  
Shear Strength ◽  
Laboratory Tests ◽  
Undrained Shear Strength ◽  
Clayey Soils ◽  
Undrained Shear

scholarly journals Impact of Particle Sizes, Mineralogy and Pore Fluid Chemistry on the Plasticity of Clayey Soils

2021 ◽  
Vol 13 (21) ◽  
pp. 11741
Author(s):  
Jongmuk Won ◽  
Junghee Park ◽  
Junki Kim ◽  
Junbong Jang
Keyword(s):  
Particle Size ◽  
Shear Strength ◽  
Undrained Shear Strength ◽  
Ionic Concentration ◽  
Pore Fluid ◽  
Particle Sizes ◽  
Clayey Soils ◽  
Fluid Chemistry ◽  
Pore Fluid Chemistry ◽  
Undrained Shear

The current classification of clayey soils does not entail information of pore fluid chemistry and particle size less than 75 µm. However, the pore fluid chemistry and particle size (at given mineralogy) are critical in the plasticity of clayey soils because of their impact on negative charge density. Therefore, this study extensively discusses the description of clay with respect to mineralogy, particle sizes, and pore fluid chemistry based on liquid and plastic limits of kaolinite, illite, and bentonite, and estimates undrained shear strength from the observed liquid limits. The liquid limits and undrained shear strength estimated from the observed liquid limits as a function of mineralogy (clay type), particle size, and ionic concentration reveal the need of incorporating pore fluid chemistry and particle size into the fines classification system. Furthermore, multiple linear regression models developed in this study demonstrate the importance of particle size and ionic concentration in predicting the liquid limit of clayey soils. This study also discusses the need for a comprehensive understanding of fines classification for proper interpretation of natural phenomena and engineering applications for fine-grained sediments.

Variability of undrained shear strength cu within one organic soli layer

2017 ◽  
Vol 32 (1) ◽  
pp. 8-13
Author(s):  
Krzysztof Załęski ◽  
Patryk Juszkiewicz ◽  
Paweł Szypulski
Keyword(s):  
Shear Strength ◽  
Laboratory Tests ◽  
Organic Soil ◽  
Undrained Shear Strength ◽  
Test Results ◽  
Geotechnical Parameters ◽  
Soil Layers ◽  
Undisturbed Samples ◽  
Strength Tests ◽  
Undrained Shear

For the purpose of this article a program of geotechnical laboratory tests was performed on organic soil (mud) samples from one geological layer. All undisturbed samples were taken within the same excavation in square grid with a side about 30 cm. Differences between specimen parameters were found both at basic test results and at shear strength tests results. Based on all performed tests authors suggest carefulness in assuming geotechnical parameters of organic soil layers because of theirs spatial variability even in very close vicinity.

scholarly journals EFFECT OF DRYING-WETTING PROCESS ON FRICTION CAPACITY AND ADHESION FACTOR OF PILE FOUNDATION IN CLAYEY SOIL

2015 ◽  
Vol 77 (11) ◽  
Author(s):  
Daniel Tjandra ◽  
Indarto Indarto ◽  
Ria Asih Aryani Soemitro
Keyword(s):  
Shear Strength ◽  
Water Content ◽  
Pile Foundation ◽  
Undrained Shear Strength ◽  
Clayey Soils ◽  
Content Change ◽  
Adhesion Factor ◽  
Undrained Shear ◽  
Water Content Change ◽  
Friction Capacity

Clayey soils had a seasonal water content change, which occurred in the zone known as active zone. This change happen due to the seasonal drying and wetting cycles, which affects the fluctuation of water table. The water content variation causes the change in undrained shear strength and these changes have an impact to the friction capacity and adhesion factor of pile foundation. This paper discusses the undrained shear strength, friction capacity of pile and adhesion factor of piles under drying and wetting cycles. Research was conducted on two different types of clayey soils. Laboratory experiments for varying soil water content were done. Soil samples were placed in a cylinder tube, the concrete pile model was then inserted into the soil. The diameter of the tube was about 15 times of the pile diameter. Loading test was carried out to investigate pile friction capacity. The result of this study showed that there was great effect of seasonal water content change on undrained shear strength, friction capacity and also adhesion factor of pile in the clayey soils.

scholarly journals Influence of the rotation of principal stress directions on undrained shear strength

2013 ◽  
Vol 45 (2) ◽  
pp. 183-192 ◽  
Author(s):  
Grzegorz Wrzesiński ◽  
Zbigniew Lechowicz
Keyword(s):  
Shear Strength ◽  
Principal Stress ◽  
Laboratory Tests ◽  
Cohesive Soil ◽  
Undrained Shear Strength ◽  
Hollow Cylinder Apparatus ◽  
Stress Directions ◽  
Anisotropic Consolidation ◽  
Undrained Conditions ◽  
Undrained Shear

Abstract Influence of the rotation of principal stress directions on undrained shear strength. The paper presents the results of research on natural cohesive soil carried out in the Hollow Cylinder Apparatus (HCA). The main goal of this study was to determine the values of undrained shear strength at different angle of the rotation of principal stress directions. The research were carried out with anisotropic consolidation and shearing in undrained conditions (CAU) on cohesive soil with overconsolidation ratio (OCR) equals 4 and plasticity index (Ip) about 77%. The results of laboratory tests allow to assess the influence of the rotation of principal stress directions on undrained shear strength

Undrained shear strength in stability calculation of embankments and foundations on soft clays

1980 ◽  
Vol 17 (4) ◽  
pp. 591-602 ◽  
Author(s):  
Rolf Larsson
Keyword(s):  
Shear Strength ◽  
Laboratory Tests ◽  
Undrained Shear Strength ◽  
Test Results ◽  
Stability Calculation ◽  
Soft Clays ◽  
Empirical Relations ◽  
Undrained Shear

Undrained shear strength of soft clays is usually measured by field vane tests or laboratory tests. The relevance of the test results in stability calculations of embankments and foundations is discussed. Empirical relations for undrained shear strengths obtained from Scandinavian clays are compared with reported failures.

scholarly journals Testing of Undrained Shear Strength in a Hollow Cylinder Apparatus

2015 ◽  
Vol 37 (2) ◽  
pp. 69-73 ◽  
Author(s):  
Grzegorz Wrzesiński ◽  
Zbigniew Lechowicz
Keyword(s):  
Shear Strength ◽  
Principal Stress ◽  
Hollow Cylinder ◽  
Laboratory Tests ◽  
Undrained Shear Strength ◽  
Cohesive Soils ◽  
Silty Clay ◽  
Hollow Cylinder Apparatus ◽  
Stress Directions ◽  
Undrained Shear

Abstract The paper presents the results of tests performed in a Torsional Shear Hollow Cylinder Apparatus on undisturbed cohesive soils. The tests were performed on lightly overconsolidated clay (Cl) and sandy silty clay (sasiCl). The main objective of the tests was to determine the undrained shear strength at different angles of rotation of the principal stress directions. The results of laboratory tests allow assessing the influence of rotation of the principal stress directions on the value of undrained shear strength that should be used during designing structure foundations

Study on Influence of Unloading of Vacuum on Stability of Embankment Improved by Vacuum Combined with Preloading

2012 ◽  
Vol 178-181 ◽  
pp. 1688-1693
Author(s):  
Ji Fu Liu ◽  
Guan Feng An ◽  
Gang Zheng
Keyword(s):  
Shear Strength ◽  
Theoretical Analysis ◽  
Safety Factor ◽  
Laboratory Tests ◽  
Soft Clay ◽  
Undrained Shear Strength ◽  
Soft Ground ◽  
Analysis Laboratory ◽  
The Stability ◽  
Undrained Shear

In order to study influence of unloading of vacuum on stability of embankment whose soft ground is improved by vacuum combined with preloading, the change of effective stress of soft clay in the improved area is analyzed when vacuum is unloaded and the undrained shear strength of soft clay in the improved area after unloading of vacuum is deduced. Changes of undrained shear strength of soil and stability of embankment owing to unloading of surcharge are also analyzed for comparison. It is shown by theoretical analysis, laboratory tests and a project that the undrained shear strength of soft clay improved by vacuum combined preloading is decreased after unloading of vacuum and the stability of embankment after unloading of vacuum should be taken into account for design. Safety factor of stability of embankment increases after unloading of surcharge since decrease ratio of load of embankment is more than decrease ratio of undrained shear strength of clay.

scholarly journals Undrained Shear Strength cu and Undrained Elastic Modulus Eu of Anthropogenic Soils from Laboratory Tests

2021 ◽  
Vol 906 (1) ◽  
pp. 012118
Author(s):  
Matylda Tankiewicz ◽  
Joanna Strózyk ◽  
Zofia Zieba
Keyword(s):  
Shear Strength ◽  
Laboratory Tests ◽  
Triaxial Compression ◽  
Clay Fraction ◽  
Strain Curve ◽  
Undrained Shear Strength ◽  
Engineering Practice ◽  
Compression Tests ◽  
Materials Used ◽  
Undrained Shear

Abstract Undrained shear strength cu and undrained elasticity modulus Eu are one of the basic mechanical parameters describing soil properties in engineering practice. In a simple way cu can be established by fall cone test or, similar as the Eu modulus, can be determined from the stress-strain curve obtained from the uniaxial or triaxial compression tests. The paper presents the results of laboratory tests od cu and Eu parameters carried out on anthropogenic soil in uniaxial compression tests and fall cone tests. The soil used in the study represented different types of materials used in earthworks - containing different share of clay fraction. Tests were provided on the soil in different bulk density and water contents. The paper proposes a method of estimating Eu50 on the basis of cone penetrometer tests. Such test does not require any additional preparation and can be performed directly on the soil compacted in the cylinder of the Proctor’s apparatus, which allows for a quick assessment of the soil elasticity parameters.

Sign in / Sign up

Export Citation Format

Share Document