Correlation of shear strength, hydraulic conductivity, and thermal gradients with sediment disturbance: South Pass region, Mississippi Delta

1985 ◽  
Vol 5 (2) ◽  
pp. 113-119 ◽  
Author(s):  
D. H. Abbott ◽  
R. W. Embley ◽  
M. A. Hobart
Keyword(s):  
Shear Strength ◽  
Hydraulic Conductivity ◽  
Mississippi Delta ◽  
Thermal Gradients ◽  
Sediment Disturbance

THE EFFECTS OF SLOPE POSITION AND CROPPING SEQUENCE ON SOIL PHYSICAL PROPERTIES IN PRINCE EDWARD ISLAND

1988 ◽  
Vol 68 (4) ◽  
pp. 763-774 ◽  
Author(s):  
LINNELL M. EDWARDS
Keyword(s):  
Shear Strength ◽  
Hydraulic Conductivity ◽  
Prince Edward Island ◽  
Soil Depth ◽  
Aggregate Stability ◽  
Penetration Resistance ◽  
Slope Position ◽  
Bottom Slope ◽  
Freezing And Thawing ◽  
Freeze Thaw

Soil physical characteristics were examined at depth intervals of 0–15 and 15–30 cm over three slope positions (top-, mid-, and bottom-slope) for three cropping sequences (hay-barley, cereals-barley, and potato-barley). Hydraulic conductivity was a significant (P ≤ 0.05) 40–50% greater at top-slope than mid- or bottom-slope, and aggregate stability percentage was a significant 6–7% greater at bottom-slope than mid- or top-slope when the soil aggregates were pretreated by freezing and thawing (freeze/thaw). Under the potato-barley sequence shear strength, penetration resistance and bulk density were significantly greater than any other sequence by up to 29, 21 and 15%, respectively; while hydraulic conductivity and maximum penetration depth were, respectively, up to 65 and 28% lower than any other sequences. Under hay-barley, hydraulic conductivity and aggregate stability (freeze/thaw) were, respectively, up to a significant 82 and 10% greater than any other sequence. There was, therefore, significantly more compaction under potato-barley and more soil physical enhancement under hay-barley than other respective sequences. Disease severity was up to 55% greater at bottom-slope than at mid-slope or top-slope for Birka barley, which also showed a significant linear decrease (r2 = 0.89) in yield with increasing shear strength. Yield of Perth barley showed a significant linear increase with increasing soil depth (r2 = 0.92) and clay-silt content (r2 = 0.78). Key words: Aggregate stability (freeze/thaw), crop rotation, penetration resistance, shear strength, barley, potatoes, hay

scholarly journals Insights into Desiccation and Self-Healing of Bentonite in Geosynthetic Clay Liners under Thermal Loads

2019 ◽  
Vol 92 ◽  
pp. 03006
Author(s):  
Abbas El-Zein ◽  
Bowei Yu ◽  
Ali Ghavam-Nasiri
Keyword(s):  
Hydraulic Conductivity ◽  
Mechanical Model ◽  
Thermal Gradients ◽  
Self Healing ◽  
Transient Phase ◽  
Geosynthetic Clay Liners ◽  
Clay Liners ◽  
Sodium Bentonite ◽  
Mechanical Loads ◽  
Numerical Investigations

Geosynthetic Clay Liners (GCLs) are widely used for protecting groundwater from pollution sources at the surface, including applications in which they are subject to significant thermal gradients. Hence, sodium bentonite in the GCL may undergo significant dehydration and cracking, and the GCL might fail as a result. The paper presents outcomes of a set of recent experimental and numerical investigations exploring the propensity of bentonite to desiccate and self-heal, as well as means of mitigating the effect of thermal gradients on the hydraulic conductivity of GCLs. An elasto-plastic thermo-hydro-mechanical model was found to yield reasonable predictions of experimental behaviour, except for the transient phase of pre-heating hydration. Introducing an airgap between the GCL and the heat source can reduce the extent of desiccation and its effects on hydraulic conductivity. However, the effectiveness of the solution will depend on other factors including subgrade, magnitude of thermal and mechanical loads and type of GCL.

Development of a Homogeneous Model Municipal Solid Waste

2013 ◽  
Vol 831 ◽  
pp. 331-335 ◽  
Author(s):  
Ren Peng ◽  
Yu Jing Hou ◽  
Xue Dong Zhang ◽  
Qing Lei Sun
Keyword(s):  
Shear Strength ◽  
Hydraulic Conductivity ◽  
Physical Properties ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Homogeneous Model ◽  
Saturated Hydraulic Conductivity ◽  
Unit Weight ◽  
The Real ◽  
Compression Factor

A model waste mixing with kaolin, sand, and peat was developed. The physical properties of the waste were compared with the real municipal solid waste (MSW). The influence of unit weight on compression factor, shear strength, and saturated hydraulic conductivity was acquired. In addition, the homogeneous of the soil model was detected using the IWHR 450g-ton centrifuge and the newly developed centrifuge-robot.

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.

scholarly journals Hydraulic conductivity and undrained shear strength of clay-construction and demolition solid waste materials mixtures

2021 ◽  
Vol 44 (2) ◽  
pp. 1-9
Author(s):  
Mohammed Abdulnafaa ◽  
Muwafaq Awad ◽  
Ali Cabalar ◽  
Nurullah Akbulut ◽  
Burak Ozufacik
Keyword(s):  
Shear Strength ◽  
Hydraulic Conductivity ◽  
Clayey Soil ◽  
Experimental Tests ◽  
Dry Weight ◽  
Undrained Shear Strength ◽  
K Value ◽  
Soil Plasticity ◽  
Mixing Ratios ◽  
Undrained Shear

The study aims to investigate the effects of three different construction and demolition materials (CDMs), including crushed waste asphalt (CWA), crushed waste bricks (CWB), and crushed waste concrete (CWC), on some geotechnical properties of low plastic clayey soil, particularly, the undrained shear strength (Su) and the hydraulic conductivity (k). A set of experimental tests were performed on clayey soil and on clayey soil-CDM mixtures at mixing ratios of 5%, 10%, 15%, and 20% by dry weight. The results show that the soil plasticity decreases as the CDMs increase. Quantitatively, it is found a maximum of 12%, 6%, and 6% decrease in the liquid limits (LL) and a maximum of 9%, 4%, and 6% decrease in the plasticity limit (PI) of the mixtures with 20% of CWA, CWB, and CWC, respectively. The results of the Su estimated empirically from the fall cone tests show that the Su decreases as the CDMs increase. The Su reduces by approximately 10% and 2% of the mixtures with 20% CWA and CWB, respectively. But the Su is not affected by the CWC additive for water content lower than approximately 35%. The k value increases as the CDMs increase. The results show that the reported k value increases by 75%, 79%, and 247% of the mixtures with 20% of CWA, CWB, and CWC, respectively. Additionally, the k values obtained from the consolidation test confirm the findings of the effect of the CDMs on the coefficient of hydraulic conductivity.

Influence of Density on the Hydraulic and Mechanical Properties of Sands

2014 ◽  
Vol 580-583 ◽  
pp. 659-664
Author(s):  
Osvaldo de Freitas Neto ◽  
Olavo Francisco dos Santos Jr. ◽  
Ricardo Nascimento Flores Severo
Keyword(s):  
Shear Strength ◽  
Hydraulic Conductivity ◽  
Triaxial Compression ◽  
Friction Angle ◽  
Coarse Fraction ◽  
Direct Shear ◽  
Direct Shear Tests ◽  
Strength Tests ◽  
Constant Head ◽  
Direct Shear Testing

This article aims at assessing the influence of relative density on the hydraulic conductivity and shear strength of two sands, denominated S01 and S02, derived from different regions and formation processes. S01 is wind-blown and S2 alluvial. The results of characterization and hydraulic conductivity in constant head tests were presented for both samples. The results of direct shear tests with sand S01 prepared with 5 different void ratios were also presented, for a vertical stress of 100kPa. The S02 sample was prepared with 4 different void ratios and these underwent direct shear testing with vertical stresses of 25kPa and 150kPa. This sample was prepared with the maximum and minimum void ratio and submitted to strength tests at CD triaxial compression with confining stresses of 50kPa, 100kPa and 200kPa. Results showed that even with different grain sizes, and under different density conditions, there were no significant variations in the permeability of the materials. With respect to shear strength, sand S01 obtained higher angle of friction values than sand S02, even though the latter had a higher percent coarse fraction. Sand S02 was relatively similar in terms of friction angle values obtained in direct shear and triaxial compression strength tests.

scholarly journals Special reinforcement solutions of railway permanent ways’ soil substructures

2021 ◽  
Author(s):  
Muayad Habashneh
Keyword(s):  
Shear Strength ◽  
Hydraulic Conductivity ◽  
Soil Stabilization ◽  
Effective Solution ◽  
Geosynthetic Reinforcement ◽  
Rehabilitation Process ◽  
Comprehensive Review ◽  
The Core ◽  
Main Target ◽  
Increasing Demand

This mini review aims to summarize relevant international publications. Thus, based on this, giving a comprehensive review about the reinforcement solutions of permanent ways' soil substructure. Generally, the core weakness of soil is its inadequacy to resist tensile stresses. The main target of strengthening the soil is to enhance the engineering characteristics of the soil to build up specific parameters such as shear strength, compressibility, density, and hydraulic conductivity. In addition, special reinforcement techniques of railway permanent ways' soil substructures will be considered in this paper due to the increasing demand of improving railways and rehabilitation process. The main findings of this study that there are a lot of special reinforcement techniques which can be considered as effective solution for soil stabilization such as geosynthetic reinforcement.

A Theoretical Study of Some Unsaturated Properties for Different Soils

2018 ◽  
Vol 26 (9) ◽  
pp. 149-165
Author(s):  
Mohammed Nawaf Jirjees Alzaidy
Keyword(s):  
Shear Strength ◽  
Hydraulic Conductivity ◽  
Water Content ◽  
Unsaturated Soil ◽  
Basic Relation ◽  
Soil Suction ◽  
Unsaturated Hydraulic Conductivity ◽  
Clayey Silt ◽  
Two Parameters ◽  
Different Soils

Soil–water characteristic curves (SWCC) can be defined as the relationship between the water content and suction of an unsaturated soil. It considered a basic relation to explanation of the engineering behaviour of unsaturated soil such as hydraulic conductivity and shear strength, So the study of SWCC is useful to reduce the time and cost of unsaturated soil testing for different engineering purposes. An approach model has been used to predict the SWCC for different soils. The influence of the soils on SWCC shape, the unsaturated hydraulic conductivity and shear strength parameters have been studied in this paper using mathematical models. The results of SWCC show that suction of clay soil is bigger than sandy soil, while the clayey silt soils exhibit an intermediate behaviour at same water content. The values of unsaturated shear strength are increasing while the unsaturated hydraulic conductivity is decreasing with increasing soil suction. This behaviour of the last two parameters with soil suction should be taken in consideration for engineering purposes.

Effects of Fines Content on Hydraulic Conductivity and Shear Strength of Granular Structural Backfill

2014 ◽  
Vol 2462 (1) ◽  
pp. 1-6
Author(s):  
Brian W. Gomez ◽  
Mandar M. Dewoolkar ◽  
John E. Lens ◽  
Christopher C. Benda
Keyword(s):  
Shear Strength ◽  
Hydraulic Conductivity ◽  
Fines Content
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