Large-Scale Direct Shear Test on Scrap Tire Strip Reinforced Brick Powder

In order to clear the shear mechanism of the scrap tire strips reinforced brick powder, a series of large-scale direct shear tests were carried out on the pure brick powder and reinforced brick powder. The scrap tire strips with 50 mm in length, 5 mm in thickness, and 10 mm, 30 mm, and 50 mm in width were put into the brick powder with volume percentages of 2%, 6%, and 10% as reinforcement, respectively. The results show that the internal friction angle and cohesion increase by adding scrap tire strips into brick powder. The peak shear strength of reinforced brick powder initially decreases, thereafter increases and finally decreases with the increase of volume percentage of the scrap tire strips. And the peak shear strength increases in the initial stage and then decreases with the increase of the scrap tire strips dimension. The optimal dimension and volume percentage of the scrap tire strips are 50 mm × 30 mm × 5 mm and 6%, respectively. In addition, the scrap tire strips provide constraints to restrict the vertical displacement of integral reinforced brick powder, and relative to the pure brick powder, the larger the vertical load is, the greater the decrease of vertical displacement is.

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Evaluation of Interface Shear Strength Properties of Geogrid Reinforced Foamed Recycled Glass Using a Large-Scale Direct Shear Testing Apparatus

Advances in Materials Science and Engineering ◽

10.1155/2015/235424 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8 ◽

Cited By ~ 7

Author(s):

Arul Arulrajah ◽

Suksun Horpibulsuk ◽

Farshid Maghoolpilehrood ◽

Wisanukorn Samingthong ◽

Yan-Jun Du ◽

...

Keyword(s):

Shear Strength ◽

Large Scale ◽

Vertical Displacement ◽

Strength Properties ◽

Direct Shear ◽

Interface Shear Strength ◽

Interface Shear ◽

Mse Wall ◽

Tensile Forces ◽

Mechanically Stabilized

The interface shear strength properties of geogrid reinforced recycled foamed glass (FG) were determined using a large-scale direct shear test (DST) apparatus. Triaxial geogrid was used as a geogrid reinforcement. The geogrid increases the confinement of FG particles during shear; consequently the geogrid reinforced FG exhibits smaller vertical displacement and dilatancy ratio than FG at the same normal stress. The failure envelope of geogrid reinforced FG, at peak and critical states, coincides and yields a unique linear line possibly attributed to the crushing of FG particles and the rearrangement of crushed FG after peak shear state. The interface shear strength coefficientαis approximately constant at 0.9. This value can be used as the interface parameter for designing a reinforced embankment and mechanically stabilized earth (MSE) wall when FG is used as a lightweight backfill and triaxial geogrid is used as an extensible earth reinforcement. This research will enable FG, recently assessed as suitable for lightweight backfills, to be used together with geogrids in a sustainable manner as a lightweight MSE wall. The geogrid carries tensile forces, while FG reduces bearing stresses imposed on the in situ soil. The use of geogrid reinforced FG is thus significant from engineering, economical, and environmental perspectives.

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Influence of Structural Plane Microscopic Parameters on Direct Shear Strength

Advances in Civil Engineering ◽

10.1155/2018/9178140 ◽

2018 ◽

Vol 2018 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Yanhui Cheng ◽

Weijun Yang ◽

Dongliang He

Keyword(s):

Particle Size ◽

Shear Strength ◽

Internal Friction ◽

Direct Shear Test ◽

Shear Test ◽

Friction Angle ◽

Internal Friction Angle ◽

Direct Shear ◽

Stiffness Ratio ◽

Structural Plane

Structural plane is a key factor in controlling the stability of rock mass engineering. To study the influence of structural plane microscopic parameters on direct shear strength, this paper established the direct shear mechanical model of the structural plane by using the discrete element code PFC2D. From the mesoscopic perspective, the research on the direct shear test for structural plane has been conducted. The bonding strength and friction coefficient of the structural plane are investigated, and the effect of mesoscopic parameters on the shear mechanical behavior of the structural plane has been analyzed. The results show that the internal friction angle φ of the structural plane decreases with the increase of particle contact stiffness ratio. However, the change range of cohesion is small. The internal friction angle decreases first and then increases with the increase of parallel bond stiffness ratio. The influence of particle contact modulus EC on cohesion c is relatively small. The internal friction angle obtained by the direct shear test is larger than that obtained by the triaxial compression test. Parallel bond elastic modulus has a stronger impact on friction angle φ than that on cohesion c. Under the same normal stress conditions, the shear strength of the specimens increases with particle size. The shear strength of the specimen gradually decreases with the increase of the particle size ratio.

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Study on Water Characteristic Curve and Shear Characteristics of Typical Unsaturated Silty Clay in Shaoxing

Geofluids ◽

10.1155/2021/5510535 ◽

2021 ◽

Vol 2021 ◽

pp. 1-15

Author(s):

Ruiqian Wu ◽

Youzhi Tang ◽

Shaohe Li ◽

Wei Wang ◽

Ping Jiang ◽

...

Keyword(s):

Shear Strength ◽

Internal Friction ◽

Unsaturated Soil ◽

Direct Shear Test ◽

Shear Test ◽

Characteristic Curve ◽

Friction Angle ◽

Matric Suction ◽

Silty Clay ◽

Direct Shear

In order to probe into one simplified method to predict the shear strength of Shaoxing unsaturated silty clay, the test method combining unsaturated soil consolidation instrument and conventional direct shear instrument is used to study the shear strength, and the method is compared and verified with the results of equal suction direct shear test. The research results show that the soil water characteristic curve fitted by the measured data points and VG model has obvious stage characteristics in the range of 0~38 kPa, 38~910 kPa, and 910~10000 kPa. The shear strength of unsaturated soil measured by consolidation meter combined with conventional direct shear test is in good agreement with that measured by equal suction direct shear test in the range of 0~500 kPa. The results show that the shear strength, total cohesion, and effective internal friction angle of soil increase slightly with the increase of matric suction in the range of 0~38 kPa. When the matric suction increases from 38 kPa to 500 kPa, the shear strength and total cohesion force of the soil have similar stage characteristics with the SWCC, which first increases and then tends to be stable, while the effective internal friction angle changes slightly. Finally, taking the air-entry value as the demarcation point, an improved model of unsaturated shear strength is proposed by analyzing the error value. Compared with the measured value, the absolute value of relative error is basically kept in the range of 5%~10%, which is close to the measured value.

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Influence of Maximum Particle Diameter on the Mechanical Behavior of Soil-Rock Mixtures

Advances in Civil Engineering ◽

10.1155/2020/8850221 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9

Author(s):

Zhuoling He ◽

Junyun Zhang ◽

Tao Sun

Keyword(s):

Shear Strength ◽

Large Scale ◽

Direct Shear Test ◽

Shear Test ◽

Particle Diameter ◽

Size Difference ◽

Direct Shear ◽

Fine Grained ◽

Fine Grained Soil ◽

Maximum Particle

With the steady development of the development of the western region in China, the construction of mountain highways has developed rapidly, and the soil-rock mixed filler, as an excellent filler, is widely used in the subgrade filling of mountain highways. Unlike ordinary fine-grained soil, the source of the soil-rock mixtures (S-RMs) is not unique, and the particle size difference is large and the water content is not uniform, resulting in very complicated mechanical properties. But the current highway embankment codes are still mainly established on the fine-grained soil. It is not fully applicable to soil-rock filled embankment. Based on soil-rock filled embankment engineering practice, this research uses a large-scale direct shear test to research the mechanical characteristics of the S-RMs with different maximum particle diameters. According to the large-scale direct shear test of S-RMs with different maximum particle diameters, the shear displacement vs shear stress curve, shear dilation, and strength characteristics with maximum particle diameter were analyzed. Results demonstrate that whether secondary hardening occurs mainly depends on the normal stress and the maximum particle diameter of the filler. At different maximum particle diameters, the horizontal displacement vs vertical displacement curves of the S-RMs can be roughly divided into continuous shearing and beginning of shearing and quick dilation. And the shear strength increases with the increase of the maximum particle diameter. Moreover, the cohesion decreases first and then increases with the increase of the maximum particle diameter, and the internal friction angle increases with the increase of the maximum particle diameter. Therefore, some RBs with large particle diameter added to filler can effectively improve the shear strength of the S-RMs, which may be valuable for realistic engineering.

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Shear Strength of Sand–Clay Interfaces Through Large-Scale Direct Shear Tests

Arabian Journal for Science and Engineering ◽

10.1007/s13369-020-04459-w ◽

2020 ◽

Vol 45 (5) ◽

pp. 4343-4357

Author(s):

Zhong-Liang Zhang ◽

Zhen-Dong Cui ◽

Ling-Zi Zhao

Keyword(s):

Shear Strength ◽

Large Scale ◽

Direct Shear ◽

Shear Tests ◽

Direct Shear Tests

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

Periodica Polytechnica Civil Engineering ◽

10.3311/ppci.15766 ◽

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.

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Effect of Rock Particle Content on the Mechanical Behavior of a Soil-Rock Mixture (SRM) via Large-Scale Direct Shear Test

Advances in Civil Engineering ◽

10.1155/2019/6452657 ◽

2019 ◽

Vol 2019 ◽

pp. 1-16

Author(s):

Longqi Liu ◽

Xuesong Mao ◽

Yajun Xiao ◽

Qian Wu ◽

Ke Tang ◽

...

Keyword(s):

Shear Strength ◽

Normal Stress ◽

Large Scale ◽

Direct Shear Test ◽

Shear Test ◽

Volumetric Strain ◽

Direct Shear ◽

Stress Strain ◽

Particle Content ◽

Rock Particle

The mechanical strength of the landslide deposits directly affects the safety and operation of the roads in the western mountainous area of China. Therefore, the research is aimed at studying the mechanisms of a landslide deposit sample with different rock particle contents by analyzing its characteristics of the stress-strain behavior, the “jumping” phenomenon, the volumetric strain, and the shear strength parameters via a large-scale direct shear test. Stress-strain results show that stress-strain curves can be divided into 3 different stages: liner elastic stage, yielding stage, and strain-hardening stage. The shear strength of SRM behaves more like “soil” at a lower rock particle content and behaves more like “rock joints” at a higher rock particle content. Characteristics of the “jumping” phenomenon results show that the “intense jumping” stage becomes obvious with the increasing rock particle content and the normal stress. However, the lower the rock particle content is, the more obvious the “jumping” phenomenon under the same normal stress is. Volumetric strain results show that the sample with a lower rock particle content showed a dilatancy behavior under the low normal stress and shrinkage behavior under the high normal stress. The dilatancy value becomes smaller with the increasing normal stress. The maximum shear stress value of the rock particle content corresponds to the maximum value of dilatancy or shrinkage. We also conclude that the intercept of the Mohr failure envelope of the soil-rock mixture should be called the “equivalent cohesion,” not simply called the “cohesion.” The higher the normal stress and rock particle content are, the bigger the equivalent cohesion and the internal friction angle is.

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Shear Strength and Pull-Out Response of Tire Shred-Sand Mixture Reinforced with Deformed Steel Bars

Advances in Civil Engineering ◽

10.1155/2020/5185093 ◽

2020 ◽

Vol 2020 ◽

pp. 1-15

Author(s):

Beenish Jehan Khan ◽

Irshad Ahmad ◽

Hassan Nasir ◽

Abdullah Abdullah ◽

Qazi Khawar Gohar

Keyword(s):

Shear Strength ◽

Large Scale ◽

Friction Angle ◽

Sand Mixture ◽

Strain Behavior ◽

Backfill Material ◽

Pull Out ◽

Tire Shreds ◽

Steel Bars ◽

Different Diameters

The use of scrap tires in various engineering applications has been extensively explored. The present study has the following aim: to evaluate the suitability of tire-sand mixtures as backfill material based on its shear strength. To achieve this objective, modified Proctor compaction tests were performed on tire shred-sand mixture with mixing proportions by weight of tire shreds and sand (0/100, 20/80, 30/70, and 40/60) using different sizes of tire shreds (50 mm, 75 mm, and 100 mm). Based on the results of the modified Proctor compaction test, the two mixing proportions, i.e., tire shred/sand, 20/80 and 30/70, respectively, were selected. Large-scale direct shear test indicated higher internal friction angle and cohesion values for tire shred-sand mixtures (30/70) with 100 mm tire size (38.5° and 19 kPa) as compared with sand-only backfill material (30.9° and 0 kPa). Based on stress-strain behavior plots, it was indicated that the inclusion of tire shreds imparts ductility to backfill mixtures. To achieve the second objective, the pull-out tests were performed with deformed steel bars of two different diameters (12.7 mm and 15.8 mm) embedded in various backfill mixtures prepared with tire shreds of three different sizes (50, 75, and 100 mm). The pull-out test result indicated that the deformed steel bars exhibit higher pull-out resistance in tire shred-sand mixtures (9.9 kN/m) compared with sand-only backfill material (4.1 kN/m).

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Direct Shear Strength of Clay Reinforced with Coir Fiber

UKaRsT ◽

10.30737/ukarst.v4i2.1020 ◽

2020 ◽

Vol 4 (2) ◽

pp. 151

Author(s):

Anita Widianti ◽

Willis Diana ◽

Maratul Hasana

Keyword(s):

Shear Strength ◽

Dry Weight ◽

Friction Angle ◽

Strength Test ◽

Fiber Content ◽

High Plasticity ◽

Coir Fiber ◽

Direct Shear ◽

Maximum Increase ◽

Shear Strength Test

Indonesia is the largest coconut producing country in the world. However, the resulting coir waste is still rarely used for structural materials. This research studied the effect of random inclusion of coir fiber on the shear strength of clay with high plasticity. The carried test in this study is a direct shear strength test. The fiber content variations used are 0%, 0.25%, 0.50%, 0.75%, and 1% of the dry weight of the mixture with a fiber length of between 30 mm to 50 mm. The results show that the reinforcement of coir fiber can increase the cohesion and friction angle. The maximum increase in cohesion value was obtained at fiber content of 0.75%, which was 39.66%. The increase in the value of the friction angle was obtained at 1% fiber content, which was 46.67%. The optimum coir fiber content was achieved at the fiber content of 0.75%. With this content, the value of the shear strength reaches its maximum with an increase of 39.4% at a normal stress of 8.071 kPa.

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Characteristics of Direct Shear and Particle Breakage of Pebble Gravel Materials

Geofluids ◽

10.1155/2020/8820045 ◽

2020 ◽

Vol 2020 ◽

pp. 1-13

Author(s):

Chenjie Hong ◽

Man Huang ◽

Danyu Zhang ◽

Pingshan Shou ◽

Zhiyong Zhu

Keyword(s):

Particle Size ◽

Shear Strength ◽

Large Scale ◽

Size Range ◽

Normal Load ◽

Particle Breakage ◽

Direct Shear ◽

Particle Size Range ◽

Relationship Model ◽

Characteristic Particle

Particle size is an important factor affecting the Thermal-Hydraulic-Mechanical (THM) coupling behavior of graveled rock mass, especially for the shear mechanical properties. In this study, three groups of the particle size range and nine particle grading samples are designed for a large-scale direct shear test. The relationships between shear stress and shear displacement, shear strength, stress ratio, shear strength parameters, and particle breakage of pebble gravel are analyzed. The influence of particle size range and grade on the strength and particle breakage of gravel material is discussed. Results show evident particle breakage in the process of direct shear, and the degree of fragmentation is controlled by the normal load and the particle size distribution of the sample. The shear strength of the sample is no longer applicable to Mohr-Coulomb strength theory because of particle breakage that is more in line with the power function relationship. Shear strength of pebble gravel material has scale effect, and a corresponding relationship model between friction coefficient f of material and characteristic particle size of the sample is proposed.

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