Some geotechnical characteristics of fragmented Queenston Shale

1985 ◽  
Vol 22 (3) ◽  
pp. 403-408 ◽  
Author(s):  
R. H. Caswell ◽  
B. Trak
Keyword(s):  
Experimental Study ◽  
Particle Size ◽  
Shear Strength ◽  
Granular Material ◽  
Key Words ◽  
Strength Properties ◽  
Stress Strain ◽  
Triaxial Apparatus ◽  
Geotechnical Characteristics ◽  
Strain Behaviour

This paper presents the results of an experimental study to determine the stress–strain behaviour of fragmented Queenston Shale from Russell, Ontario and to investigate how its strength properties altered when the material was subjected to repeated slaking cycles. Slaking tests showed that large (cobble-size) blocks of the material degrade rapidly to a particle size of 20 mm upon exposure to water and air. Consolidated drained tests in a large triaxial apparatus under monotonic loading conditions on specimens of fresh and slaked material were performed. They indicate that the shear strength of fragmented Queenston Shale of particle size smaller than 20 mm is not affected by slaking. Key words: Queenston Shale, compaction shale, granular material, rockfill, slaking, shear strength, consolidated drained tests.

Post-Peak Behaviour of Sensitive Clays in Undrained Shear

1968 ◽  
Vol 5 (2) ◽  
pp. 59-68 ◽  
Author(s):  
B Ladanyi ◽  
J P Morin ◽  
C Pelchat
Keyword(s):  
Shear Strength ◽  
Indirect Method ◽  
Peak Stress ◽  
Large Strains ◽  
Peak Strain ◽  
Stress Strain ◽  
Strain Behaviour ◽  
Structural Breakdown ◽  
Undrained Shear

The post-peak stress-strain behaviour in undrained shear of three different clays has been investigated by using an indirect method. This method, which is in principle similar to that used by Kallstenius (1963), consists in first compressing a clay specimen to a given post-peak strain between two parallel platens and subsequently determining its current remoulded strength by the laboratory vane method. By a repeated compression procedure, axial strains of up to 200 per cent have been attained. As the three clays tested differed widely in sensitivity, a comparison of their post-peak behaviour made clearly apparent the effect of structural breakdown on the reserve shear strength at large strains.

The Experimental Study of the Influence of the Matric Suction on the Unsaturated Soil Strength

2014 ◽  
Vol 580-583 ◽  
pp. 514-517 ◽  
Author(s):  
Cui Ran Liu
Keyword(s):  
Experimental Study ◽  
Shear Strength ◽  
Moisture Content ◽  
Unsaturated Soil ◽  
Matric Suction ◽  
Saturated Soil ◽  
Triaxial Apparatus ◽  
Soil Shear Strength ◽  
Soil Triaxial Apparatus ◽  
Water Contents

With modified unsaturated soil triaxial apparatus, unsaturated soil shear strength of the tests under the condition of different water contents are done. Experimental results show that the matric suction exist in unsaturated soil and increases with the decrease of moisture content. And the shear strength of unsaturated soil is higher than that of saturated soil. Shear strength of unsaturated soil varies as the matric suction and water content. The shear strength increases when the matric suction increases. when soil tend to be saturated, the matric suction will tend to be zero. And the shear strength of unsaturated soil values gradually close to the strength of the saturated soil.

Shear strength and stress—strain behaviour of Athabasca oil sand at elevated temperatures and pressures

1987 ◽  
Vol 24 (1) ◽  
pp. 1-10 ◽  
Author(s):  
J. G. Agar ◽  
N. R. Morgenstern ◽  
J. D. Scott
Keyword(s):  
Shear Strength ◽  
Oil Sands ◽  
Elevated Temperatures ◽  
Triaxial Compression ◽  
Substantial Reduction ◽  
Hyperbolic Model ◽  
Oil Sand ◽  
Hydrocarbon Gases ◽  
Stress Strain ◽  
Strain Behaviour

The results of a series of triaxial compression tests on undisturbed samples of Athabasca oil sand at elevated temperatures ranging from 20 to 200 °C are summarized. The material tested had experienced gradual unloading and depressurization as a result of erosion in the Saline Creek valley near Fort McMurray. More deeply buried oil sands are known to contain much higher concentrations of dissolved hydrocarbon gases in the pore fluids. The measured shear strength of Athabasca oil sand did not change significantly as a result of the increased temperatures that were applied. The strength of Athabasca oil sand (at 20–200 °C) was found to be greater than comparable shear strengths reported for dense Ottawa sand (at 20 °C). Although heating to 200 °C had little effect on shear strength, it is recognized that pore pressure generation during undrained heating may cause substantial reduction of the available shearing resistance, particularly in gas-rich oil sands. The experimental data were used to investigate the influence of such factors as stress path dependency, microfabric disturbance, and heating to elevated temperatures on the shear strength and stress–strain behaviour of oil sand. Curve fitting of the test data suggests that the hyperbolic model is a useful empirical technique for stress—deformation analyses in oil sands. Hyperbolic stress—strain parameters derived from the experimental results for Athabasca oil sand are presented. Key words: oil sand, Athabasca oil sand, tar sand, shear strength, stress, strain, deformation, heating, high temperature, elevated temperatures, high pressure, elevated pressure, thermal properties, drained heating, undrained heating, triaxial compression testing.

scholarly journals Comparative Study in Method of Compaction by Consolidated Drained and Direct Shear Test

2020 ◽  
Vol 78 (2) ◽  
pp. 143-152
Author(s):  
Abdul Samad Abdul Rahman ◽  
N. Sidek ◽  
Juhaizad Ahmad ◽  
N. Hamzah ◽  
M. I. F. Rosli
Keyword(s):  
Shear Strength ◽  
Bearing Capacity ◽  
Triaxial Test ◽  
Direct Shear Test ◽  
Shear Test ◽  
Void Ratio ◽  
Direct Shear ◽  
Test Results ◽  
Stress Strain ◽  
Strain Behaviour

Soil compaction has been a common practice in the construction of highways, embankments, earth dams and other related structures where the condition of the soil is high in void ratio and therefore having a very low in bearing capacity. Therefore, the soil needs to be compacted in order to minimize the void ratio and in the same time would results in having a very high bearing capacity to sustain load. Nevertheless, only a few researches have been done to investigate the method of compaction using different energy on the behavior of shear strength by consolidated drained and direct shear test. In this research, the effect of different compaction in energy of 25 number of blows compared to 40 number of blows on the stress-strain behaviour of drained triaxial test has been done and findings of the data are to be compared with direct shear test. Results reveal that there is an increase in soil unit weight by using different energy in compaction with an increase of 5% from 1790 kg/m3 to 1880 kg/m3 for 25 and 40 number of blows respectively. However, the stress-strain behaviour of the specimens shows differently when compared between consolidated drained triaxial and direct shear test. The shear strength for direct shear-stress is at higher value compared to drained triaxial test. For drained triaxial test, results reveal that the effective friction angles are increase only about 1% from 37° to 38°. This is due to the soil particles rearranging itself with the different applied pressures thus eliminating the effects of different energy on the shear strength of the specimens. However, for direct shear test, the shear strength increases drastically from 29° to 32°. The increase of the shear strength is more likely influence by the soil particle arrangement due to the impact of the energy of the no of blows to the desired specimen.

scholarly journals Behaviour of tire shred – sand mixtures

2004 ◽  
Vol 41 (2) ◽  
pp. 227-241 ◽  
Author(s):  
Jorge G Zornberg ◽  
Alexandre R Cabral ◽  
Chardphoom Viratjandr
Keyword(s):  
Shear Strength ◽  
Aspect Ratio ◽  
Large Scale ◽  
Experimental Testing ◽  
Volumetric Strain ◽  
Confining Pressure ◽  
Stress Strain ◽  
Aspect Ratios ◽  
Strain Behaviour ◽  
Tire Shreds

Tire shreds and tire shred – soil mixtures can be used as alternative backfill material in many geotechnical applications. The reuse of tire shreds may not only address growing environmental and economic concerns, but also help solve geotechnical problems associated with low soil shear strength. In this study, an experimental testing program was undertaken using a large-scale triaxial apparatus with the goal of evaluating the optimum dosage and aspect ratio of tire shreds within granular fills. The effects on shear strength of varying confining pressure and sand matrix relative density were also evaluated. The tire shred content and tire shred aspect ratio were found to influence the stress–strain and volumetric strain behaviour of the mixture. The axial strain at failure was found to increase with increasing tire shred content. Except for specimens of pure tire shreds and with comparatively high tire shred content, the test results showed a dilatant behaviour and a well-defined peak shear strength. The optimum tire shred content (i.e., the one leading to the maximum shear strength) was approximately 35%. For a given tire shred content, increasing the tire shred aspect ratio led to increasing overall shear strength, at least for the range of tire shred aspect ratios considered in this study. The shear strength improvement induced by tire shred inclusions was found to be sensitive to the applied confining pressure, with larger shear strength gains obtained under comparatively low confinement.Key words: tire shreds, shear strength, reinforcement, triaxial testing, stress–strain behaviour.

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