scholarly journals Influence of moisture content of cohesive soils on their shear strength

2017 ◽  
Vol 2017 (5) ◽  
pp. 10-19 ◽  
Author(s):  
Tymoteusz Zydroń ◽  
Małgorzata Wojciechowska-Dymańska ◽  
Andrzej Gruchot ◽  
Tomasz Zalewski
Keyword(s):  
Shear Strength ◽  
Moisture Content ◽  
Optimum Moisture Content ◽  
Cohesive Soils ◽  
Test Results ◽  
Angle Of Internal Friction ◽  
Shearing Rate ◽  
Strength Tests ◽  
Shear Box ◽  
Direct Shear Apparatus

Influence of moisture content of two cohesive soils on their shear strength was the purpose of the tests. The shear strength tests were carried out in a standard direct shear apparatus of dimensions of the box 6 x 6 x 1,8 cm. Each sample of assumed moisture content was preliminary compacted at Proctor apparatus, then was cut using a square cutter and to set into the shear box. Each series of samples were tested at four values of moisture content: equal, lower and higher than optimum moisture content. One series of samples, sheared at moisture content higher than optimum moisture content, the shearbox during consolidation and shearing was filled with the water to the level corresponding to shearing plane. Main tests were done using shearing rate equal to 1,0 mm.min-1 and time of consolidation was equal to 12 hours. Additional tests were done using shearing rate equal to 0,05 mm.min-1 and the samples during consolidation and shearing were saturated. Test results revealed that the most beneficial values of shear strength were obtained at optimum moisture content or lower that optimum moisture content. It stated that the increase of moisture content cause decrease of angle of internal friction and the highest values of cohesion was obtained at optimum moisture content. Comparison of test results obtained for series of samples sheared at optimum moisture content revealed that saturation of soil sample and low shearing rate cause very significant reduction of obtained values of cohesion.

Reliability of Shear-Box Tests Upon Soaking Process on the Sand Soil in Al-Najaf City

2020 ◽  
Vol 857 ◽  
pp. 212-220
Author(s):  
Mohammed Sh. Mahmood ◽  
Waseem H. Al-Baghdadi ◽  
Asaad M. Rabee ◽  
Suhad H. Almahbobi
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Sandy Soil ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Engineering Structures ◽  
Angle Of Internal Friction ◽  
Shear Box ◽  
Testing Condition ◽  
Direct Shear Apparatus

Accurate prediction of the soil shear strength parameters is essential in the reliable geotechnical design of civil engineering structures. This recent paper investigates the effect of the dry testing condition on the shear strength parameters of the sandy soil using the direct shear apparatus and compared with the saturated condition tests in previous researches on the same soil. The dry soil, usually above the water table, is the principal condition of the Al-Najaf city soil in Iraq. Samples are selected from the site of the University of Kufa, which represents the sandy soil of the city. For reliability purposes, the soil is exposed to different pre-soaking durations (one, two, and four weeks) then air-dried for shear tests. The main results revealed that the angle of internal friction (Φ) tested as a dry sample decreases about -6% up to two-weeks soaking then recovered upon four-week soaking about +6%. Compared to the saturated testing, there are increases in F between 6%-17% from saturated tests. Finally, it is recommended to aware in the selection of testing conditions for calculations of the angle of internal friction.

scholarly journals Influence of randomly oriented fibres on shear strength of mineral soils

2019 ◽  
Vol 52 (2) ◽  
pp. 235
Author(s):  
Tymoteusz Zydroń ◽  
Andrzej Gruchot
Keyword(s):  
Shear Strength ◽  
Moisture Content ◽  
Shear Velocity ◽  
Cohesive Soil ◽  
Dry Mass ◽  
Soil Test ◽  
Test Results ◽  
Medium Sand ◽  
Mineral Soils ◽  
Direct Shear Apparatus

The purpose of the paper was to determine two things: the influence of type and amount of reinforcement on shear strength of soil and the relation between the efficiency of reinforcement and soil moisture content. Shear strength was determined in a direct shear apparatus in a box with a square section of 80x80 mm. The range of normal stress was from 25 to 150 kPa and the shear velocity was 1.0 mm×min<sup>-1</sup>. The tests were carried out on medium sand and clayey coarse silt at two moisture contents and with two types of reinforcement - polyolefine fibres and 40x3 mm foil stripes. The addition of reinforcement was 0.5 and 1.0% in relation to the dry mass of soil. Test results indicated that using polyolefine fibres as dispersed reinforcement in a sandy soil increased its shear strength. Whereas the influence of using foil stripes on shear strength was little. However, using both types of reinforcement in a cohesive soil increased its shear strength and this influence was particularly clear at higher moisture content.

scholarly journals Shear strength of clayey soils from the vicinity of Gorlice and Ciężkowice

2015 ◽  
Vol 47 (3) ◽  
pp. 225-236
Author(s):  
Tymoteusz Zydroń ◽  
Ewa Prawica
Keyword(s):  
Shear Strength ◽  
Residual Strength ◽  
Linear Equations ◽  
Clayey Soils ◽  
Angle Of Internal Friction ◽  
Strength Tests ◽  
Non Linear ◽  
Shearing Strain ◽  
Direct Shear Apparatus ◽  
Non Linear Equations

Abstract The work presents results of maximum and residual strength tests of six clayey soils from the landslide areas near Gorlice and Ciężkowice. The tests were carried out in a direct shear apparatus on samples of dimensions 60 × 60 mm that were sheared at least three times. A shearing strain rate was equal 0.1 mm·min–1, and the range of horizontal deformation of the samples was equal 20%. The results of the tests revealed that multiple shearing of the soil caused a significant decrease of its shear strength, resulting in significant changes in cohesion, and the smaller changes in the angle of internal friction. It was shown that the three-time shearing reduced the initial shear strength of about 50%, and further three series of shearing decreased it approximately 15% more. The study also showed that by using a Coulomb-Mohr shear strength linear equation, the analyzed soils had a little residual cohesion. Therefore, to describe the characteristics of the residual strength, there were used two non-linear equations proposed by Mesri and Shanien (2003) and Lade (2010), which led to the same results. It was also shown that the use of non-linear characteristics of the residual strength at low values of the normal stresses gave more unfavourable results of stability calculations in relation to the method based on the linear strength characteristic taking into consideration the presence of the residual cohesion.

scholarly journals Strength Tests and Numerical Simulations of Loess Modified by Desulfurization Ash and Fly Ash

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 512
Author(s):  
Zhi Cheng ◽  
Xinrong Cheng ◽  
Yuchao Xie ◽  
Zhe Ma ◽  
Yuhao Liu
Keyword(s):  
Shear Strength ◽  
Fly Ash ◽  
Power Plants ◽  
Utilization Rate ◽  
Direct Shear ◽  
Test Results ◽  
Mass Ratio ◽  
Direct Shear Tests ◽  
Strength Tests ◽  
Actual Test

Desulfurization ash and fly ash are solid wastes discharged from boilers of power plants. Their utilization rate is low, especially desulfurization ash, most of which is stored. In order to realize their resource utilization, they are used to modify loess in this paper. Nine group compaction tests and 32 group direct shear tests are done in order to explore the influence law of desulfurization ash and fly ash on the strength of the loess. Meanwhile, FLAC3D software is used to numerically simulate the direct shear test, and the simulation results and the test results are compared and analyzed. The results show that, with the increase of desulfurization ash’s amount, the shear strength of the modified loess increases first and then decreases. The loess modified by the fly ash has the same law with that of the desulfurization ash. The best mass ratio of modified loess is 80:20. When the mass ratio is 80:20, the shear strength of loess modified by the desulfurization ash is 12.74% higher than that of the pure loess on average and the shear strength of loess modified by fly ash is 3.59% higher than that of the pure loess on average. The effect of the desulfurization ash on modifying the loess is better than that of the fly ash. When the mass ratio is 80:20, the shear strength of loess modified by the desulfurization ash is 9.15% higher than that of the fly ash on average. Comparing the results of the simulation calculation with the actual test results, the increase rate of the shear stress of the FLAC3D simulation is larger than that of the actual test, and the simulated shear strength is about 8.21% higher than the test shear strength.

scholarly journals Effect of Sand Percentage on the Compaction Properties and Undrained Shear Strength of Low Plasticity Clay

2021 ◽  
Vol 9 (1) ◽  
pp. 16-20
Author(s):  
Iyad Alkroosh ◽  
Ali Al-Robay ◽  
Prabir Sarker ◽  
Saif Alzabeebee
Keyword(s):  
Shear Strength ◽  
Moisture Content ◽  
Undrained Shear Strength ◽  
Optimum Moisture Content ◽  
Dry Density ◽  
Sand Content ◽  
Compression Tests ◽  
Maximum Dry Density ◽  
Sand Mixture ◽  
Undrained Shear

This paper investigates the influence of sand content on the mechanical behavior of a low plasticity clay that collected from south of Iraq (Sumer town). Samples have been prepared with sand contents of 0%, 10%, 20%, 30%, and 40% of the clay weight. Standard Proctor and unconfined compression tests have been carried out and the optimum moisture content, maximum dry density, and undrained shear strength have been determined. The results show a gradual increasing trend of the maximum dry density with the increase of the sand content up to 30%. The highest dry density reaches 1.90 g/cm3 corresponding to an optimum moisture content of 12%. In addition, this paper shows that the undrained shear strength is inversely proportional to the increase of the percentage of sand. The results of this work provide a useful addition to the literature regarding the behaviour or low plasticity clay-sand mixture.

Analysis for Influence Factors of Cold Recycling Mixture Compaction Test

2012 ◽  
Vol 204-208 ◽  
pp. 1633-1637
Author(s):  
Yong Bing Wang ◽  
Guo Qiang Ying ◽  
Jian Lin Hu ◽  
Hua Wei Wei ◽  
Qian Zhang
Keyword(s):  
Moisture Content ◽  
Water Absorption ◽  
Base Material ◽  
Optimum Moisture Content ◽  
Dry Density ◽  
Surface Material ◽  
Test Results ◽  
Maximum Dry Density ◽  
Compaction Test ◽  
Recycled Material

In order to study the factors which influence the inorganic binder stabilized material’s compaction test results, different recycled material content therefore different reclaimed gradation mixtures are tested while varying the amount of cement. The experiment results show that contents of the recycled base material and the recycled surface material on the compaction test results are determined by the change of their density and water absorption ratio. Dry density of the recycled mixture increases with the increase of the reclaimed base material density. Low water absorption ratio of the recycled material reduces the reclaimed mixture’s optimum moisture content. Density of the reclaimed wearing surface material reduces the maximum dry density of the reclaimed mixture because the old wearing surface material has lower density. Its low water absorption reduces the optimum moisture content of the recycled mixture. Influence of cement content on compaction test results is the increase of the cement content can enhance the maximum dry density and optimum moisture content of the recycled material. Through the analysis of the results of the compaction test, the key factors in the recycled material compaction test are unveiled.

Effect of sand percentage on the compaction properties and undrained shear strength of low plasticity soft clay

2021 ◽  
Author(s):  
Iyad Alkroosh ◽  
◽  
Ali Al-Robay ◽  
Prabir Sarker ◽  
Saif Alzabeebee ◽  
...  
Keyword(s):  
Shear Strength ◽  
Moisture Content ◽  
Soft Clay ◽  
Undrained Shear Strength ◽  
Optimum Moisture Content ◽  
Dry Density ◽  
Sand Content ◽  
Compression Tests ◽  
Maximum Dry Density ◽  
Undrained Shear

This study investigated the influence of sand content on the mechanical behaviour of a low plasticity clay found in Iraq. Samples were prepared with sand contents of 0%, 10%, 20%, 30%, and 40% of the weight of the clay. Standard Proctor and unconfined compression tests were carried out and the optimum moisture content, maximum dry density, and undrained shear strength were determined. The results showed a gradual increasing trend of the maximum dry density with the increase of the sand content up to 30%. The highest dry density reached was 1.90 gm/cm3 corresponding to an optimum moisture content of 12%. In addition, it was also found that the undrained shear strength was inversely proportional to the increase of the percentage of sand. Thus, the dry density of the clay could be increased well above 1.70 g/cm3, which is the minimum dry density accepted as a compacted subgrade according to the Iraqi General Specifications for Roads and Bridges (2003); hence, the rejected low plasticity clay could be utilised by mixing with sand. The reasons for the increase of the dry density and the decrease of the undrained shear strength has been extensively discussed in the paper.

Effect of Glass Fiber on Shear Strength of Soil

2018 ◽  
Vol 775 ◽  
pp. 603-609
Author(s):  
Himadri Shekhar Saha ◽  
Debjit Bhowmik
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Moisture Content ◽  
Glass Fiber ◽  
Water Content ◽  
Soil Samples ◽  
Fiber Content ◽  
Triaxial Tests ◽  
Angle Of Internal Friction ◽  
Increase With Increase

This paper investigates the effect of glass fiber reinforcement on the shear strength properties of the sand clay mixture. The soil samples were prepared by mixing 50% of locally available Barak river sand with 50% of local clay soil. Triaxial tests were conducted on the soil samples containing five different percentage of fiber to know the effect of fiber content on the shear strength of the soil. Unconsolidated Undrained (UU) Triaxial tests were conducted under three different confining pressures for each sample. Samples were prepared with five different values of moisture content considering 2% less than OMC (Optimum Moisture Content), 1% less than OMC, OMC, 1% more than OMC, and 2% more than OMC to study the effect of water content (w) on behavior of fiber reinforced soil. A parametric study has been carried out in this paper to know the effect of different influencing parameters on the cohesion value and angle of internal friction. The results show that the failure stress and angle of internal friction increase with increase in fiber content up to an optimum value then decrease. On the other hand, the cohesion value increases consistently with increase in fiber content. The study also indicates that the peak deviator stress, angle of internal friction and cohesion values increase with increase in water content up to an optimum value which is less than OMC then decrease with further increase in water content.

Preliminary report on a new method for determining the shear strength of a soil surface - the resin plate method

Soil Research ◽  
1993 ◽  
Vol 31 (5) ◽  
pp. 539 ◽  
Author(s):  
N Collis-George ◽  
PE Tolmie ◽  
H Moahansyah
Keyword(s):  
Shear Strength ◽  
Moisture Content ◽  
Preliminary Report ◽  
Soil Surface ◽  
Horizontal Stress ◽  
Rigid Plate ◽  
Plate Method ◽  
Torsional Shear ◽  
Box Method ◽  
Shear Box

The proposed method consists of pouring a thin layer of resin onto the soil surface. This impregnates the soil to approx. 2 mm regardless of moisture content. The resultant rigid plate of resin and soil is detached from the soil beneath by applying a horizontal stress. Results for three sands and one soil are compared with those from the torsional shear box method. The method is quick, inexpensive and the results are highly reproducible. The implications of the method are discussed.

Differences of Shear Strength between Undisturbed and Remolded Soils of Lands for Agriculture and Forestry in Menglianggu Watershed of Linyi City

2012 ◽  
Vol 599 ◽  
pp. 815-819
Author(s):  
Xiao Ming Zhang ◽  
Qian Jin Liu ◽  
Xing Xiu Yu
Keyword(s):  
Particle Size ◽  
Shear Strength ◽  
Soil Mechanics ◽  
Dry Density ◽  
Land Uses ◽  
Factors Affecting ◽  
Angle Of Internal Friction ◽  
Undisturbed Soils ◽  
Direct Shear Apparatus ◽  
Different Soils

To find the effects of pedoturbation on soil erosion of lands for agriculture and forestry in Menglianggu watershed of Linyi city from soil mechanics, shear strengths of 3 typical land uses (6 different soils) which are undisturbed and remolded respectively were measured by direct shear apparatus. Effects of particle size and binding materials on shear strength were analyzed by comparing shear properties of undisturbed and remolded soils with the same dry density, water content and vertical loads. The results show that all the angle of internal friction ( ) and most of soil cohesion ( ) of undisturbed soils are bigger than that of remolded soils; The final shearing stress also comply with the law above; The main factors affecting shear strength are soil particle size and binding materials.

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