scholarly journals Direct Shear Test: Normal and Tangential Stresses Evaluation According to Constant and Variable Shearing Area

2016 ◽  
Author(s):  
Šarūnas Skuodis ◽  
Arnoldas Norkus
Keyword(s):  
Direct Shear Test ◽  
Shear Test ◽  
Test Procedure ◽  
Horizontal Displacement ◽  
Strength Properties ◽  
Direct Shear ◽  
Angle Of Internal Friction ◽  
Testing Procedures ◽  
Direct Shear Tests ◽  
Tangential Stresses

Investigations of soil shear strength properties for Baltic Sea shore sand along Klaipėda city is presented. Investigated sand angle of internal friction (φ) and cohesion (c) is determined via two different direct shear tests procedures. First procedure is standard and ordinary in geotechnical practice, when direct shear test is provided using constant shearing area. Second test procedure is different because shearing area according to horizontal displacement each test second is recalculated and reducing during horizontal movement. According to these two different testing procedures provided comparison of normal and tangential stresses.

scholarly journals DIRECT SHEAR TESTS WITH EVALUATION OF VARIABLE SHEARING AREA / TIESIOGINIO KIRPIMO BANDYMAI ĮVERTINANT KINTAMĄ KERPAMĄJĮ PLOTĄ

2014 ◽  
Vol 6 (5) ◽  
pp. 499-503 ◽  
Author(s):  
Šarūnas Skuodis ◽  
Tadas Tamošiūnas
Keyword(s):  
Test Procedure ◽  
Horizontal Displacement ◽  
Strength Properties ◽  
Direct Shear ◽  
Shear Tests ◽  
Angle Of Internal Friction ◽  
Testing Procedures ◽  
Direct Shear Tests ◽  
Tangential Stresses ◽  
Soil Shear Strength

Investigations of soil shear strength properties for Baltic Sea shore sand along Klaipėda city are presented. Investigated sand angle of internal friction (φ) and cohesion (c) is determined via two different direct shear tests procedures. First procedure is standard and ordinary in geotechnical practice, when direct shear test is provided using constant shearing area A0. Second test procedure is different because shearing area according to horizontal displacement each test second is recalculated. This recalculated shearing area author’s call corrected shearing area A. Obtained normal and tangential stresses’ difference via two different testing procedures was 10%. Šiame straipsnyje yra pristatyta idėja, kaip įvertinti grunto kerpamojo stiprumo parametrus, t. y. vidinės trinties kampą (φ) ir sankibą (c). Eksperimentiniams bandymams atlikti buvo naudotas Baltijos jūros pakrantės smėlinis gruntas ties Klaipėda. Grunto tiesioginio kirpimo bandymai atlikti dviem skirtingomis kirpimo metodikomis. Pirmoji metodika yra standartizuota ir įprasta atliekant geotechninius tyrimus, kai kerpamasis plotas yra vertinamas kaip pastovus plotas A. Antroji kirpimo metodika skiriasi nuo pirmosios grunto kirpimo ploto įvertinimu. Antrojoje metodikoje grunto kerpamasis plotas yra perskaičiuojamas tiesiogiai pagal horizontalųjį poslinkį. Horizontaliojo poslinkio indikatoriaus rodmenys yra registruojami kiekvieną sekundę, todėl kas sekundę yra perskaičiuojamas vis naujas grunto kerpamasis plotas. Atliekant bandymus skirtingomis metodikomis, nustatytas vertikalaus normalinio ir tangentinio įtempių skirtumas, kuris apytiksliai lygus 10 %.

scholarly journals Effects of Clay and Moisture Content on Direct Shear Tests for Clay-Sand Mixtures

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Muawia A. Dafalla
Keyword(s):  
Internal Friction ◽  
Moisture Content ◽  
Direct Shear Test ◽  
Shear Test ◽  
Horizontal Displacement ◽  
Direct Shear ◽  
Shear Tests ◽  
Angle Of Internal Friction ◽  
Direct Shear Tests ◽  
Moisture Contents

The direct shear test using shear box is commonly recommended by practicing geotechnical engineers to obtain the cohesion and angle of internal friction for granular soils. The clay liners involve sand as a main constituent with added clay of variable proportions. This research aims at investigating the reliability of using the direct shear test for different clay contents and different moisture contents using an adequate shearing strain. These factors were found to affect the bilinear trends of shear force versus horizontal displacement profile as well as vertical displacement versus horizontal displacement curves. The cohesion of the mixture was found to increase consistently with the increase of clay content. Increase in moisture content was found to cause a drop in both cohesion and angle of internal friction. These changes are not independent of the density state of clay-sand mixtures. Standard compaction properties for a range of clay-sand mixtures were investigated. This work provides the general trends expected in direct shear tests for clay-sand mixtures of variable clay and moisture contents.

The Determination of Young's Modulus from the Direct Shear Test

1972 ◽  
Vol 9 (4) ◽  
pp. 504-507 ◽  
Author(s):  
D. K. J. Noonan ◽  
J. F. Nixon
Keyword(s):  
Young’S Modulus ◽  
Direct Shear Test ◽  
Shear Test ◽  
Young's Modulus ◽  
Horizontal Displacement ◽  
Direct Shear ◽  
The Finite Element Method ◽  
Direct Shear Tests ◽  
The Relationship

A method is developed for determining Young's Modulus from a direct shear test. The finite element method is employed to compute stresses in a sample of rock subjected to direct shear. From the results of the analysis, the relationship between the shear load, horizontal displacement and the Young's Modulus is established for different sample geometries. The use of the solution is illustrated. Since direct shear tests are often used for strength testing the necessity for conducting alternative tests to determine the deformability characteristics of a rock mass is reduced.

scholarly journals Shear strength characteristics of Jerash expansive soil

2021 ◽  
Vol 3 (2) ◽  
pp. 74-80
Author(s):  
Talal Masoud
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Water Content ◽  
Direct Shear Test ◽  
Shear Test ◽  
Expansive Soil ◽  
Content Increase ◽  
Direct Shear ◽  
Initial Water ◽  
Angle Of Internal Friction

The results of the direct shear test on Jerash expansive soil show the effect of the initial water content on the cohesion (c) and on the angel of internal friction ( ) [shear strength parameters].it show that, as the initial water increase, the cohesion (c) of Jerash expansive soil also increase up to the shrinkage limit, after that increase of water even small amount, decrease the cohesion of the soil. On the other hand, the results of direct shear test show also  that as the water content increase, the angle of internal friction ( )remain unchanged up to shrinkage limit , any increase of water cause a large decrease on the angle of internal friction of Jerash expansive soil.

Numerical Simulation of Interface Softening for Large Size Direct Shear Test

2011 ◽  
Vol 368-373 ◽  
pp. 3230-3235
Author(s):  
Zhao Yun Xiao ◽  
Wei Xu ◽  
Yan Sheng Deng ◽  
Fan Tu
Keyword(s):  
Numerical Simulation ◽  
Direct Shear Test ◽  
Shear Test ◽  
Friction Model ◽  
Secondary Development ◽  
Direct Shear ◽  
Shear Tests ◽  
Direct Shear Tests ◽  
Softening Behavior ◽  
Large Size

The interface of non-woven geotextile and HDPE geomembrane based on direct shear test has an obvious softening behavior. This paper adopts displacement-softening model that proposed by Esterhuizen and conducts secondary development by using ABAQUS and its embedded FRIC subroutine, making further efforts to conduct numerical simulation of interface of non-woven geotextile and HDPE geomembrane based on large-size direct shear tests. Results show that the developed interface friction model can simulate the characteristics of interface softening of certain materials better, thus providing a method when study the interface softening characteristic of materials.

scholarly journals Determining the Shear Strength Properties of a Soil-geogrid Interface Using a Large-scale Direct Shear Test Apparatus

2020 ◽  
Author(s):  
Jakub Stacho ◽  
Monika Sulovska ◽  
Ivan Slavik
Keyword(s):  
Shear Stress ◽  
Shear Strength ◽  
Large Scale ◽  
Direct Shear Test ◽  
Shear Test ◽  
Strength Properties ◽  
Coarse Grained ◽  
Direct Shear ◽  
Test Apparatus ◽  
Fine Gravel

The paper deals with the laboratory testing of coarse-grained soils that are reinforced using a geogrid. The shear strength properties were determined using a large-scale direct shear test apparatus. The tests were executed on original as well as on reinforced soil, when the geogrid was placed on a sliding surface, which permitted determining the shear strength properties of the soil-geogrid interface. The aim of the tests was to determine the interface shear strength coefficient α, which represents the ratio of the shear strength of the soil-geogrid interface to the unreinforced soil. The tests were executed on 3 samples of coarse-grained materials, i.e., poorly graded sand, poorly graded fine gravel and poorly graded medium gravel. Two types of geogrids were tested, i.e., a woven polyester geogrid and a stiff polypropylene geogrid. The results of the laboratory tests on the medium gravel showed that the reduction coefficient α reached higher values in the case of the stiff polypropylene geogrid. In the cases of the fine gravel and sand, the values of the interface coefficient α were similar to each other. The shear strength of the interface was reduced or was similar to the shear strength of unreinforced soil in a peak shear stress state, but significantly increased with horizontal deformations, especially for the fine gravel and sand. The largest value of the coefficient α was measured in the critical shear stress state. Based on the results of the testing, a correlation which allows for determining the optimal grain size distribution was obtained.

scholarly journals Reliability Analysis of a Direct Shear Test of Modified Iron Tailings Based on the Monte Carlo Algorithm

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Ping Jiang ◽  
Jian Qian ◽  
Na Li
Keyword(s):  
Monte Carlo ◽  
Direct Shear Test ◽  
Shear Test ◽  
Friction Angle ◽  
Direct Shear ◽  
Shear Tests ◽  
Type Curve ◽  
Direct Shear Tests ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle

The resource utilization of iron tailings is of great significance for all countries in the world. Considering the particle composition and physicochemical characteristics of iron tailings, fiber and lime were used to modify iron tailings. The fiber content was 0%, 0.25%, 0.5%, 0.75%, and 1%, and the lime content was 0%, 2%, 4%, 8%, and 10%, respectively. Through a direct shear test, the shear stress displacement (τ-δ) curves and shear strength of modified iron tailings, under the action of a 0 freeze-thaw cycle and 1 freeze-thaw cycle, were tested. As statistics have shown that there are uncertainty factors associated with direct shear tests, the shear strength index cohesion c and internal friction angle φ of the modified iron tailings were analyzed using the Monte Carlo method. The results show that the τ-δ curve of the fiber-modified iron tailings is a hardening-type curve and that of the lime-modified iron tailings is a softening-type curve. In the direct shear tests, the main uncertain factors are the specimen diameter, vertical force, and horizontal force. The diameter of the sample obeys a normal distribution, and the vertical and horizontal forces obey a uniform distribution. The results of the Monte Carlo simulation show that both c and φ obey a normal distribution. Under a 95% confidence condition, the effect of fiber on the cohesion on iron tailings is obvious, but the effect on the internal friction angle is not obvious. However, the values of c and φ of the iron tailings are clearly improved by lime. Additionally, the iron tailings modified by a fiber content of 1% and those modified by a lime content of 8% have the best frost resistance.

scholarly journals Effect of urease enzyme and clay mixture in shear strength properties of sand

2019 ◽  
Vol 280 ◽  
pp. 04014 ◽  
Author(s):  
Aulina Reza Putri ◽  
Wiwik Rahayu ◽  
Puspita Lisdiyanti
Keyword(s):  
Shear Strength ◽  
Calcium Chloride ◽  
Direct Shear Test ◽  
Shear Test ◽  
Soil Stabilization ◽  
Strength Properties ◽  
Urea Solution ◽  
Direct Shear ◽  
Sand Mixture ◽  
Urease Enzyme

The utilization of environmentally friendly materials in soil stabilization has grown in the last decade. Recent studies have shown that adding urease enzyme in calcium chloride and urea solution will improve the shear strength properties of sand. The purpose of this paper is to introduce the usage of clay to improve the performance of calcite produced in the mixture of urease enzyme and calcium chloride-urea solution. This mixture is then mixed manually with the clay-sand mixture and its effect is further tested using a direct shear test conducted at every two weeks of curing. The test is carried out to determine the development of the shear strength properties of the stabilized sand. The results from the test show that there is a rise in the cohesion value of the sand due to the addition of the clay mixture.

scholarly journals Non-cohesive Soil Direct Shear Strength Affected with Hydrostatic Pressure

2017 ◽  
Vol 9 (5) ◽  
pp. 520-523
Author(s):  
Tadas Tamošiūnas ◽  
Šarūnas Skuodis
Keyword(s):  
Hydrostatic Pressure ◽  
Baltic Sea ◽  
Research Work ◽  
Cohesive Soil ◽  
Pressure Change ◽  
Direct Shear ◽  
Angle Of Internal Friction ◽  
Testing Procedures ◽  
Direct Shear Tests ◽  
Shearing Strength

This paper presents first results of non­cohesive soil direct shear tests with hydrostatic pressure. To reach this aim, it was chosen the Baltic Sea Klaipėda sand, due to granulometry composition and particles shape. According to this, investigated Baltic Sea sand can be called Lithuanian standard sand for scientific testing. Analysis of results revealed, that when it is increased hydrostatic pressure, the shearing strength is also increasing. Comparing air­ dry sand results with fully saturated sand and affected with 100 kPa of hydrostatic pressure, the angle of internal friction increased for 21,24%. Meanwhile, the cohesion was not changing so dramatically according to hydrostatic pressure change. Obtained results allows to proceed this research work more detailed with different loading types, testing procedures and hydrostatic pressures.

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