Influence of Water Contents on Shear Strength of Rammed Earth Wall of Earth-Building

2011 ◽  
Vol 382 ◽  
pp. 172-175
Author(s):  
Ren Wei Wu ◽  
Xing Qian Peng ◽  
Li Zhang
Keyword(s):  
Shear Strength ◽  
Water Content ◽  
Triaxial Compression ◽  
Friction Angle ◽  
World Heritage Site ◽  
Rammed Earth ◽  
Compression Tests ◽  
Rammed Earth Wall ◽  
Influence Of Water ◽  
Water Contents

As the "Fujian earth-building" have been inscribed by UNESCO in 2008 as World Heritage Site, attentions of protection about the "Fujian earth-building" has getting more and more. This article takes samples of a rammed-earth wall from Yongding earth-buildings and determines the shear strength of the samples with different water content through triaxial compression tests. The influence on shear strength of water content of rammed-earth samples is analyzed. Test results show that the shear strength of rammed-earth has much to do with the water content of the soil, the greater the water content is，the smaller the shear strength is. With water content increasing, cohesion and internal friction angle of rammed-earth were decreases, and its changing trend is of marked characteristic of stage. When water contents of rammed-earth is under some value, its cohesion changes in small ranges; when water contents of rammed-earth is over the value, its cohesion decreases with water content increasing.

scholarly journals Experimental Investigation on the Influence of Water Content on the Mechanical Properties of Coal under Conventional Triaxial Compression

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Meichang Zhang ◽  
Rongshan Nie
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Internal Friction ◽  
Water Content ◽  
Triaxial Compression ◽  
Friction Angle ◽  
Conventional Triaxial Compression ◽  
Influence Of Water ◽  
Confining Pressures ◽  
Water Contents

The presence of water is one of the most important factors in coal mining, and it has a dual influence on the mechanical behavior of rock. To study the influence of water content on the mechanical properties of coal under complicated stress conditions, dry coal specimens and wet coal specimens with water contents of 1.8% and 3.6% were conducted by uniaxial and conventional triaxial compression tests. The relations between the uniaxial compressive strength, deformation, and water content were observed. The reductions in the strength and elastic modulus under different confining pressures were obtained. The mechanical properties of coal specimens with different water contents under triaxial compression were studied. The influences of water content on the microstructure, clay minerals, internal friction angle, and cohesive force of coal were discussed. The results show that the strengths and elastic moduli of wet specimens are clearly lower than those of dry specimens under different confining pressures. The water content has a significant influence on the postfailure mechanical behavior of coal. The loss rates of strength and elastic modulus decrease with increasing confining pressure. The water content has almost no effect on the internal friction angle, while the cohesive force of the saturated specimens is 36.5% lower than that of the dry specimens. The results can provide a reference for inhibiting the occurrence of disasters during coal mining and exploiting coal efficiently.

Mechanical Properties of Bentonite-Sand Mixtures Under Triaxial Stress Condition

1994 ◽  
Vol 353 ◽  
Author(s):  
M. Umedera ◽  
A. Fujiwara ◽  
N. Yasufuku ◽  
M. Hyodo ◽  
H. Murata
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Water Content ◽  
Triaxial Compression ◽  
Confining Pressure ◽  
Strength Properties ◽  
Compression Tests ◽  
Optimum Water Content ◽  
Triaxial Compression Tests ◽  
Optimum Water

AbstractA series of triaxial compression tests is being conducted under the drained condition on bentonite and sand mixtures, known as buffer, in saturated and optimum water content states to clarify the mechanical properties of the buffer.It was found that the mechanical properties of bentonite and sand mixtures are strongly influenced by water and bentonite contents: shear strength in a saturated state is less than that in an optimum water content state; shear strength decreases rapidly with increasing bentonite content. Strength properties are much dependent on confining pressure.

Isothermal modeling of sand–bentonite mixtures at elevated temperatures

1995 ◽  
Vol 32 (1) ◽  
pp. 78-88 ◽  
Author(s):  
B.E. Lingnau ◽  
J. Graham ◽  
N. Tanaka
Keyword(s):  
Shear Strength ◽  
Elevated Temperatures ◽  
Triaxial Compression ◽  
Friction Angle ◽  
Compression Tests ◽  
Strain Behavior ◽  
Bentonite Buffer ◽  
State Boundary ◽  
Increasing Temperature ◽  
Triaxial Compression Tests

Two models are proposed for describing the stress–strain behavior of sand–bentonite (buffer) mixtures at elevated temperatures: (1) isothermal pseudoelasticity and (2) isothermal elastic-plasticity. Data to support the models come from consolidated undrained triaxial compression tests performed on dense saturated buffer specimens at effective confining stresses up to 9.0 MPa and temperatures of 26°, 65°, and 100 °C. Measurements indicate that volumes decrease with increasing temperature if the tests are carried out under drained conditions. These trends can be modelled by a family of hardening lines in semilog compression space. Power law relationships are presented for undrained shear-strength envelopes that increase in size with an increase in temperature. The slopes of unload-reload lines, κ, in semilog compression space vary with temperature and can be related to systematic variation in the friction angle [Formula: see text]. The shear modulus G50 at 50% peak strength also depends on temperature. Several plotting techniques are used to show the existence of different state boundary surfaces for each test temperature. Key words : sand–bentonite, buffer, compression, shear strength, temperature, modelling.

scholarly journals Influence of water content on the shear strength parameters of clayey soil in relation to stability analysis of a hillside in Brno region

2013 ◽  
Vol 61 (6) ◽  
pp. 1583-1588 ◽  
Author(s):  
Kristýna Bláhová ◽  
Lenka Ševelová ◽  
Pavla Pilařová
Keyword(s):  
Shear Strength ◽  
Stability Analysis ◽  
Water Content ◽  
Clayey Soil ◽  
Friction Angle ◽  
Dry Density ◽  
Stability Analyses ◽  
Influence Of Water ◽  
Moisture Conditions ◽  
Processing Stability

Shear strength of soils is highly affected by moisture conditions (i.e. water content), especially if the soil contains clay materials. Usually the laboratory specimen, which are used to determine shear strength of soil are prepared at water content and dry density same as in the field conditions, without respect to the fact, that the conditions in the future might not remain the same. For the purpose of this study soil specimen were compacted and the optimum moisture content was identified. After compaction soil was tested at the dry side of optimum water content at w = 9 %, 10 % and 11 %. Parameters of shear strength were obtained and used for stability analysis with software GEOSLOPE/W 2012. According to referenced literature, it was expected for the shear strength of the soil to decrease with increasing water content. This hypothesis was not proven for clayey soil from Brno region. Development of values of friction angle and cohesion exhibited anomalous behaviour and such development was found also for values of Factor of safety (FOS) obtained from stability analyses. Results proved the necessity of taking moisture conditions into account, when processing stability analyses, in order to achieve reliable and safe constructions.

Gravel Content Effect on the Shear Strength of Clay-Gravel Mixtures

2011 ◽  
Vol 71-78 ◽  
pp. 4685-4688 ◽  
Author(s):  
Chen Wang ◽  
Chuan Ni Zhan
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Triaxial Compression ◽  
Constant Strain Rate ◽  
Friction Angle ◽  
Confining Pressure ◽  
Internal Friction Angle ◽  
Compression Tests ◽  
Gravel Content ◽  
Confining Pressures

Gravel content is an important factor affecting the mechanical properties of clay-gravel mixtures. To study the effects of gravel content on the shear strength of clay-gravel mixtures, constant-strain-rate drained triaxial compression tests were conducted for various mixtures. The gravel contents were 30%, 40%, 50% and 70%. The confining pressures were varied from 50kPa to 300kPa. Test results indicate that the deviator stress at failure under the same confining pressure increases with the increase in gravel content. As the gravel content in the mixtures is between 30% and 50%, the shear strength is jointly attributed by clay and gravel. An increase in gravel content results in slight increases in both the cohesion intercept and internal friction angle. At gravel content of up to 70%, the shear strength of the mixture is controlled by that of the gravel, and the cohesion intercept and the internal friction angle increase sharply.

Exploring the effects of nanoscale zero-valent iron (nZVI) on the mechanical properties of lead-contaminated clay

2019 ◽  
Vol 56 (10) ◽  
pp. 1395-1405 ◽  
Author(s):  
Yong-Zhan Chen ◽  
Wan-Huan Zhou ◽  
Fuming Liu ◽  
Shuping Yi
Keyword(s):  
Shear Strength ◽  
Triaxial Compression ◽  
Morphological Characteristics ◽  
Friction Angle ◽  
Zero Valent Iron ◽  
Compression Tests ◽  
Shear Tests ◽  
Nanoscale Zero Valent Iron ◽  
Triaxial Compression Tests ◽  
Oedometer Tests

Nanoscale zero-valent iron (nZVI) is a well-known efficient nanomaterial for the immobilization of heavy metals and has been widely applied in the remediation of contaminated groundwater and soils. In this study, a series of field emission scanning electron microscopy (FESEM) analyses, vane shear tests, triaxial compression tests, and oedometer tests was conducted on lead-contaminated clay using four dosages of nZVI treatment (0.2%, 1%, 5%, and 10%). The geotechnical properties, including basic index properties, stiffness, shear strength, and compressibility, were assessed after the reaction procedure. FESEM analysis was performed to explore the potential mechanisms of nZVI treatment in terms of morphological characteristics. It was found that the plasticity index decreased gradually with increasing nZVI dosage. Treating contaminated soil with nZVI caused an increase in the vane shear strength, stiffness, and friction angle. The compression index increased gradually because of the nZVI treatment. Based on the FESEM analysis, a conclusion can be deduced that larger aggregates and conjoined structures resulting from nZVI treatment can lead to the strengthening of lead-contaminated clay.

scholarly journals Influence of water and rock particle contents on the shear behaviour of a SRM

2020 ◽  
Vol 2 (1) ◽  
pp. 29-43
Author(s):  
Longqi Liu ◽  
Xuesong Mao ◽  
Yajun Xiao ◽  
Tiequan Wang ◽  
Menglan Nie
Keyword(s):  
Shear Strength ◽  
Water Content ◽  
Normal Stress ◽  
Volumetric Strain ◽  
Friction Angle ◽  
Shear Behaviour ◽  
Mountainous Area ◽  
Particle Content ◽  
Rock Particle ◽  
Influence Of Water

Abstract The contents of both water and rock particles are important factors affecting the mechanical strength of a soil–rock mixture (SRM) filled subgrade in the western mountainous area of China. Therefore, the purpose of this paper is to study the mechanisms of reconstituted landslide deposit samples with different water and rock particle contents by analysing the characteristics of shear strength, volumetric strain and ‘jumping’ phenomenon via large-scale direct shear tests. The results show that the influence of water content on shear strength is greater than the influence of rock particle content under a lower normal stress, and the results are reversed in the case of a higher normal stress. The effect of water content on the equivalent cohesion is bigger, especially for the sample with a high rock particle content. The friction angle of the specimen with same water content increases with the increasing rock particle content, but when the number of rock particles increases to a certain extent, there is a little effect on the friction angle. However, the friction angle decreases with increasing water content at the same rock particle content. Specimens with the same rock particle content change from dilation to compression with increasing water content. Finally, the continuous stage of the ‘intense jumping’ at different water content has been analysed. The ‘jumping’ phenomenon of samples with low water and rock particle content will first strengthen and then weaken the samples with increasing normal stress.

scholarly journals Analysis on the Triaxial Shear Behavior and Microstructure of Cement-Stabilized Clay Reinforced with Glass Fibers

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Bo Ruan ◽  
Shilong Zheng ◽  
Jidong Teng ◽  
Hui Ding ◽  
Chao Ma
Keyword(s):  
Shear Strength ◽  
Glass Fiber ◽  
Test Specimen ◽  
Glass Fibers ◽  
Triaxial Compression ◽  
Friction Angle ◽  
Confining Pressure ◽  
Fiber Content ◽  
Compression Tests ◽  
Brittle Behavior

A series of triaxial compression tests were conducted to investigate the influence of the fiber content and confining pressure on the shearing characteristics of cement-stabilized clay reinforced with glass fibers. The glass fiber contents were 0, 1‰, 2‰, 3‰, and 4‰ by weight of the dry soil. The stress strain and volume change behavior, shear strength, and energy absorption of the test specimen were obtained. The results indicate that the inclusion of glass fibers can increase the shear strength, inhibit the volumetric dilation of the test specimen, and improve its brittle behavior. The cohesion of the cement-stabilized clay reinforced with 4‰ glass fiber content is 2.8 times greater than that of the cement-stabilized clay. The effect of the fiber content on the friction angle is not obvious. It is found that the glass fiber reinforcement is more substantial under a low confining pressure. The scanning electron microscopy test results show that the surface of the glass fiber is wrapped with cement hydrate crystals, which increases the bite force and friction between the fiber and the soil particles. A single fiber is similar to an anchor in the soil, which enhances the mechanical properties of the cement-stabilized clay reinforced with fibers.

Characterization of Shear Strength and Interface Friction of Organic Soil

2020 ◽  
Vol 857 ◽  
pp. 203-211
Author(s):  
Majid Hamed ◽  
Waleed S. Sidik ◽  
Hanifi Canakci ◽  
Fatih Celik ◽  
Romel N. Georgees
Keyword(s):  
Shear Stress ◽  
Shear Strength ◽  
Internal Friction ◽  
Moisture Content ◽  
Water Content ◽  
Friction Angle ◽  
Structural Materials ◽  
Organic Soil ◽  
Internal Friction Angle ◽  
Interface Friction

This study was undertaken to investigate some specific problems that limit a safe design and construction of structures on problematic soils. An experimental study was carried out to examine the influence of loading rate and moisture content on shear strength of organic soil. Influece of moisture content on interface friction between organic soil and structural materials was also attempted. A commonly used soil in Iraq was prepared at varying moisture contents of 39%, 57% and 75%. The experimental results showed that the increase in water content will decrease the shear stress and the internal friction angle. An increase of the shearing rate was found to decrease the shear stress and internal friction angle for all percetanges of water contents. Further, direct shear tests were carried out to detect the interface shear stress behavior between organic soil and structural materials. The results revealed that the increase in water content was shown to have significant negetavie effects on the interface internal friction and angle shear strength.

scholarly journals REGRESSÃO QUADRÁTICA PARA TEORES DE ÁGUA EM FUNÇÃO DA COMPACTAÇÃO DO SOLO

Irriga ◽  
2021 ◽  
Vol 26 (1) ◽  
pp. 186-194
Author(s):  
Barbara Barreto Fernandes ◽  
Indiamara Marasca ◽  
Murilo Battistuzzi Martins ◽  
Jefferson Sandi ◽  
Kleber Pereira Lanças
Keyword(s):  
Water Content ◽  
Clayey Soil ◽  
Superficial Layer ◽  
Mechanical Resistance ◽  
Mato Grosso ◽  
Randomized Design ◽  
Influence Of Water ◽  
E Mail ◽  
Mato Grosso Do Sul ◽  
Water Contents

REGRESSÃO QUADRÁTICA PARA TEORES DE ÁGUA EM FUNÇÃO DA COMPACTAÇÃO DO SOLO     Barbara Barreto Fernandes¹; Indiamara Marasca²; Murilo³ Battistuzzi Martins; Jefferson Sandi4 e Kleber Pereira Lanças5   1 Engenheira agrônoma, Rua Luis Carlos Da Silveira, 345, Tenis Clube, 19806-370, Assis – SP, Brasil. E-mail: [email protected] 2 Engenheira agrônoma, Fazenda Cachoeira do Montividiu – 75915-000, Montividiu – GO, Brasil. E-mail: [email protected] 3 Universidade Estadual de Mato Grosso do Sul – Unidade de Cassilândia. Rodovia MS 306 - km 6,4; 79540-000, Cassilândia, MS, Brasil. E-mail:  [email protected] 4 Universidade La Salle de Lucas do Rio Verde. Av. Universitária, 1000, Parque das Emas - 78455-000, Lucas do Rio Verde, MT, Brasil. E-mail: [email protected] 5 Departamento de Engenharia Rural na FCA/UNESP, Av. Universitária, 3780 - Altos do Paraíso, 18610-034, Botucatu, SP, Brasil. E-mail: [email protected]     1 RESUMO   O trabalho teve por objetivo avaliar a influência do teor de água na avaliação de resistência mecânica a penetração do solo, medida através do índice de cone. O experimento foi realizado na UNESP/FCA, Botucatu-SP, sendo selecionadas duas classes de solo: o Nitossolo Vermelho distroférrico e o Latossolo Vermelho. Utilizou-se o delineamento inteiramente casualizado, com os seguintes tratamentos de compactação: T0 = 0; T1 = 1; T2 = 2; T3 = 3; T4=5 e T5 = 10 passadas consecutivas de um trator agrícola. Utilizou-se um penetrômetro hidráulico-eletrônico para a amostragem da resistência mecânica do solo à penetração nas camadas de: 0,00 - 0,10; 0,10 - 0,20; 0,20 - 0,30; 0,30 - 0,40 m em quatro condições de teor de água. Com o aumento do tráfego, maior foi a compactação. Porém para o solo argiloso, a partir de uma passada do trator, os valores de resistência à penetração tiveram pouco aumento, não diferindo estatisticamente para a camada mais superficial (0-0,20 m) e para a camada de 0,20-0,40 m a partir de duas passadas. Para o solo de textura média, este comportamento foi observado a partir de uma passada para a camada mais superficial (0-0,20 m) e de cinco passadas para a camada de 0,20-0,40m.   Palavras-chave: resistência do solo, umidade, agregação.     FERNANDES, B. B.; MARASCA, I.; MARTINS, M. B.; SANDI, J.; LANÇAS, K. P. QUADRACTIC REGRESSION FOR WATER CONTENTS IN THE FUNCTION OF SOIL COMPACTION     2 ABSTRACT   The objective of this work was to evaluate the influence of water content in the evaluation of mechanical resistance to soil penetration, measured through the cone index. The experiment was conducted at UNESP/FCA, Botucatu - SP, being selected two classes of soil: a Nitossolo Vermelho distroférrico and a Latosolo Vermelho. A completely randomized design was used, with the following compaction treatments: T0 = 0; T1 = 1; T2 = 2; T3 = 3; T4 = 5 and T5 = 10 consecutive passes of an agricultural tractor. A hydraulic-electronic penetrometer was used to sample the mechanical resistance of the soil to penetrate the layers; 0.00 – 0.10; 0.10 - 0.20; 0.20 - 0.30; 0.30 - 0.40 m in four water content conditions. With the increase in traffic, greater was the compression. However, for the clayey soil, from a tractor pass, the penetration resistance values ​​had a small increase, not differing statistically for the most superficial layer (0 - 0.20m) and for the 0.20 - 0.40 m layer from two passes. For medium textured soil, this behavior was observed from one pass to the most superficial layer (0 - 0.20 m) and five passes to the 0.20 - 0.40 m layer.   Keywords: soil resistance; moisture; aggregation.      

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