scholarly journals Effect of temperature on the residual shear strength of fine grained soil

2021 ◽  
Author(s):  
Marcin Witowski ◽  
Witold Bogusz
Keyword(s):  
Shear Strength ◽  
Natural Variability ◽  
Heat Extraction ◽  
Effect Of Temperature ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Residual Shear Strength ◽  
Temperature Changes ◽  
Fine Grained ◽  
The Impact

Abstract The impact of low-range temperature variation on the residual shear strength parameters has been investigated. For this purpose, a standard ring shear apparatus has been subjected to low-cost modifications and equipped with thermoelectric temperature control system constructed in-house. This allowed to conduct a series of tests for clay samples at temperatures of 5°C and 20°C, which is a typical range of variation for thermo-active structures during heat extraction. In order to distinguish the impact of temperature from the natural variability of the soil samples, additional temperature changes during shearing were performed, after residual strength had been reached. The obtained results revealed an observable impact of the temperature change on the residual shear strength of tested clay; however, the variance has been close to the resolution of the measurement sensor and within the range comparable to the natural variability of fine-grained soils. Therefore, low-range temperature changes can be considered as negligible in regard to the residual shear strength parameters.

A landslide in till near Warman, Saskatchewan, Canada

1985 ◽  
Vol 22 (2) ◽  
pp. 195-204 ◽  
Author(s):  
E. Karl Sauer ◽  
E. A. Christiansen
Keyword(s):  
Shear Strength ◽  
Water Table ◽  
Back Analysis ◽  
Clay Content ◽  
Aerial Photographs ◽  
Adjacent Area ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Residual Shear Strength ◽  
Insight Into

Little information is available about typical shear strength parameters of tills in southern Saskatchewan even though till is the most common earth material used for construction in this region. The Warman landslide in the South Saskatchewan River Valley provides some insight into the shear strength characteristics of a till, and the results are compared with laboratory tests. The till is from the Upper till of the Sutherland Group, which has a high clay content relative to the underlying and overlying tills. A back analysis of the landslide produced [Formula: see text]′ = 27° assuming c′ = 0. Comparison with laboratory test data and results from a similar landslide near Lebret, Saskatchewan, suggests that [Formula: see text]′ = 22.5° with c′ = 7 kPa may be appropriate "residual" shear strength parameters. A rising water table appears to have been the main contributing factor to instability between 1969 and 1984. There is a possibility, however, that at the 1:50 return interval for flood levels on the river, erosion at the toe of the landslide debris may be a significant factor. Numerous slump scars in the form of small amphitheatres, presently inactive, can be observed in the aerial photographs of the adjacent area. These failures likely occurred intermittently, depending on fluctuating water table and river flood levels. Key words: landslide, till, correlation, stratigraphy, back analysis, shear strength, residual, aerial photographs.

Slope Stability Analysis in Anisotropic Winnipeg Clays

1974 ◽  
Vol 11 (1) ◽  
pp. 59-71 ◽  
Author(s):  
W. S. Freeman ◽  
Hugh B. Sutherland
Keyword(s):  
Shear Strength ◽  
Cross Sections ◽  
Strength Properties ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Residual Shear Strength ◽  
Lower Shear ◽  
The Stability ◽  
Mechanism Of Failure ◽  
Cut Slopes

Two major aspects of an investigation dealing with the stability of natural and cut slopes in the Winnipeg area are described. The first concerns an experimental investigation of the anisotropic shear strength characteristics of the layered Lake Agassiz clays and the second is a study of the mechanism of failure for slopes in these layered clays.Four main types of clay were investigated and it was found that the effective shear strength parameters were greater for failure across the layers than for failure along the layers. Residual shear strength parameters were also determined.Stability analyses were carried out for representative slope cross sections using circular and noncircular failure surfaces, taking into account the anisotropic shear strength effects measured in the laboratory tests.Factors of safety were found for the conventional method of analysis assuming circular arc failure surfaces and isotropic shear strength properties. These factors of safety were found to be up to 0.5 greater than those obtained from noncircular failure surfaces which partially passed along the layers and so mobilized the lower shear strength properties of these layers.

scholarly journals Effect of soil water saturation on slope stability: Tomsk case study

2019 ◽  
Vol 98 ◽  
pp. 05005 ◽  
Author(s):  
Natalia Brakorenko ◽  
Anna Leonova ◽  
Aleksey Nikitenkov
Keyword(s):  
Shear Strength ◽  
Slope Stability ◽  
Soil Water ◽  
Water Saturation ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
A Site ◽  
The Impact ◽  
Soil Water Saturation

We investigate in this article the impact of soil water saturation on the slope stability, using a site in Tomsk city as a case study. The dependency of the shear strength parameters of soil on the degree of soil water saturation has been demonstrated. The paper also provides equations for the calculation of slope stability coefficient under different values of soil water saturation.

scholarly journals Plane strain shear strength of unsaturated fiber-reinforced fine-grained soils

2021 ◽  
Author(s):  
Houman Soleimani-Fard ◽  
Diethard König ◽  
Meisam Goudarzy
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Hydraulic Conductivity ◽  
Soil Conditions ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Fine Grained ◽  
Vapor Equilibrium ◽  
Wide Range ◽  
Ductile Behavior

AbstractDiscrete randomly distributed fibers are commonly used to improve the engineering characteristics of the soil and thus soil properties such as shear strength, compressibility, density, and hydraulic conductivity. Most studies have so far focused on describing the behavior of soils containing randomly distributed fibers under dried or saturated conditions. However, the water table may seasonally fluctuate, thus generating unsaturated soil conditions. Therefore, a better understanding of the hydro-mechanical properties of unsaturated improved soils is of high necessity. In this research, the shear strength parameters of fine-grained soils were evaluated using the biaxial device available at Ruhr Universität Bochum. The applied device was modified to test unsaturated fine-grained soils with various degrees of saturation using axis translation and vapor equilibrium techniques. The experiments were conducted on fine soils containing 0, 0.5, and 1% fiber contents under a wide range of matric suctions. The ductile behavior was more noticeable in samples with lower suctions and higher straw contents. Furthermore, the shear strength of both unreinforced and reinforced fine-grained soils considerably increased by an increase in the suction. Finally, shear band inclination increased by the suction while decreasing by straw content.

SHEAR STRENGTH DEGRADATION OF SEMARANG BAWEN CLAY SHALE DUE TO WEATHERING PROCESS

2015 ◽  
Vol 77 (11) ◽  
Author(s):  
Idrus M Alatas ◽  
Samira A Kamaruddin ◽  
Ramli Nazir ◽  
Masyhur Irsyam ◽  
Agus Himawan
Keyword(s):  
Shear Strength ◽  
Drying Process ◽  
Shear Strength Parameters ◽  
Stress Release ◽  
Strength Parameters ◽  
Residual Shear Strength ◽  
Clay Shale ◽  
Saturated Clay ◽  
Internal Angle ◽  
Weathering Process

The effect of weathering processes in decreasing the shear strength of clay shale had been done in this study. The drying process of clay shale with sunlight in the laboratory up to 80 days had been conducted to create the conditions of weathered sample. The peak and residual shear strength parameters of unsaturated and saturated clay shale were obtained from triaxial laboratory test, and all samples were tested on each 8 days of weathering process. Decrease of shear strength in peak and residual condition was obtained during 80 days of the drying process. The residual shear strength parameters were distinguished between residual shear strength without stress release and with stress release of confining pressure. The results up to 80 days of unsaturated clay shale showed that the cohesion at peak stress conditions reduced to 30 % based on initial shear strength before the occurrence weathering, while the internal angle friction reduced to 64 %. Residual cohesion without and with stress release reduced to 4 % and 1 %, respectively while residual internal angle friction without and with stress release reduced to 15 % and 5 %. Similar situation also occurs for the saturated clay shale samples.

scholarly journals Statistical evaluation of shear strength parameters of fine grained tills

2021 ◽  
Author(s):  
Chandra Prakash Poudyal
Keyword(s):  
Shear Strength ◽  
Stress Ratio ◽  
Maximum Stress ◽  
Shear Failure ◽  
Triaxial Tests ◽  
Ratio Method ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Fine Grained ◽  
Deviator Stress

A statistical analysis is conducted in this study on the shear strength parameters of fine-grained tills from a series of consolidated undrained triaxial tests performed for a light rail transit project in the City of Toronto. Three different failure criteria are applied: the maximum stress ratio, the maximum deviator stress, and the residual stress. Three methods generate only minimal difference in the shear failure angle and a slight difference in cohesion. The friction angle calculated using the maximum stress ratio method ranges from 18.6 to 35.26 degrees compared with values ranging from 18.5 to 34.26 degrees by the maximum deviator stress method. The undrained shear modulus calculated from one-third and two-third peak deviator stress points generate a wide variation from 2 MPa to 167 MPa with an average value of 34 MPa.

scholarly journals Impact of shear strength parameters on slope stability

2020 ◽  
Vol 310 ◽  
pp. 00040
Author(s):  
Slávka Harabinová ◽  
Eva Panulinová
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Slope Stability ◽  
Factor Of Safety ◽  
Slip Surface ◽  
Friction Angle ◽  
Internal Friction Angle ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Fine Grained

Analysis and assessment of the slopes stability are an important in geotechnical engineering for all the times. The paper deals with the assessment of slope stability in fine-grained soils. The influence of change in shear strength parameters on the factor of safety has been studied. The factor of safety can be correctly obtained only if the critical failure surface of the slope is accurately identified and shear strength parameters are correctly. To investigate effect of soil strength parameters on the factor of safety, different values of shear strength parameters: cohesion (c), internal friction angle (ϕ), were chosen. The calculation and assessment of slope stability was made using methods which assume a circular shape of the slip surface (Bishop and Petterson method) and methods that consider the polygonal shape of the slip surface (Spencer and Janbu method). We analyzed the impact of shear strength parameters of the resulting factor of slope stability of fine grained soil. The results of the study showed that the factor of safety of the slope changes with varying cohesion c and internal friction angle ϕ.

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