scholarly journals The influence of curing time on the shear strength of fluidized fly ash

2015 ◽  
Vol 47 (2) ◽  
pp. 103-112 ◽  
Author(s):  
Andrzej Gruchot
Keyword(s):  
Shear Strength ◽  
Fly Ash ◽  
Power Plant ◽  
Internal Friction ◽  
Great Influence ◽  
Curing Time ◽  
Inverse Relation ◽  
Angle Of Internal Friction ◽  
Water Curing

Abstract The paper presents results of research on the influence of compaction and air and water curing on angle of internal friction and cohesion of fluidized fly ash from “Połaniec” Power Plant. It was stated that the increase in compaction resulted in an insignificant increase of the angle of internal friction and a quite significant increase of cohesion. While the type and time of curing had a great influence on the angle of internal friction and cohesion. The highest values of angle of internal friction were obtained in the air curing, and the lowest in the water curing whereas in case of cohesion there was an inverse relation. The rise of curing time resulted in largely increased cohesion and small changes of angle of internal friction.

scholarly journals Shear strength characteristics of Jerash expansive soil

2021 ◽  
Vol 3 (2) ◽  
pp. 74-80
Author(s):  
Talal Masoud
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Water Content ◽  
Direct Shear Test ◽  
Shear Test ◽  
Expansive Soil ◽  
Content Increase ◽  
Direct Shear ◽  
Initial Water ◽  
Angle Of Internal Friction

The results of the direct shear test on Jerash expansive soil show the effect of the initial water content on the cohesion (c) and on the angel of internal friction ( ) [shear strength parameters].it show that, as the initial water increase, the cohesion (c) of Jerash expansive soil also increase up to the shrinkage limit, after that increase of water even small amount, decrease the cohesion of the soil. On the other hand, the results of direct shear test show also  that as the water content increase, the angle of internal friction ( )remain unchanged up to shrinkage limit , any increase of water cause a large decrease on the angle of internal friction of Jerash expansive soil.

scholarly journals Shear Strength of Industrial Wastes and Their Mixtures and Stability of Embankments Made of These Materials

2019 ◽  
Vol 10 (1) ◽  
pp. 250 ◽  
Author(s):  
Andrzej Gruchot ◽  
Tymoteusz Zydroń
Keyword(s):  
Shear Strength ◽  
Fly Ash ◽  
Factor Of Safety ◽  
Triaxial Compression ◽  
Industrial Wastes ◽  
Waste Materials ◽  
Coal Waste ◽  
Angle Of Internal Friction ◽  
The Road ◽  
Earth Construction

The paper presents the results of research on the influence of compaction on the shear strength of fly ash, unburnt and burnt coal wastes, and a composite (a mixture of unburnt coal waste and 30% of fly ash). The tests were carried out in a triaxial compression apparatus on samples with a diameter and height of 10 and 20 cm, respectively. In order to verify usability of the tested waste materials for earthworks, stability calculations of the road embankment made of these materials were carried out. It was shown that the tested materials were characterized by high values of shear strength parameters, which significantly depended on compaction. The most favorable values of the angle of internal friction and cohesion were obtained for the burnt coal waste, slightly lower for the composite, and the lowest for the fly ash. Stability calculations for the road embankment model showed that the slope inclination and the load on the embankment have a significant influence on the factor of safety. It was also shown that a decrease in cohesion causes significant decrease in the factor of safety. The tests and the stability calculations showed that the tested waste materials are useful for earth construction purposes.

scholarly journals Estimation of shear strength parameters of soil using Optimized Inference Intelligence System

2021 ◽  
Vol 43 (2) ◽  
Author(s):  
Binh Thai Pham ◽  
Mahdis Amiri ◽  
Manh Duc Nguyen ◽  
Trinh Quoc Ngo ◽  
Kien Trung Nguyen ◽  
...  
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Physical Parameters ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Inference System ◽  
Angle Of Internal Friction ◽  
Intelligence System ◽  
Statistical Measures ◽  
Model Study

In recent years, machine learning techniques have been developed and used to build intelligent information systems for solving problems in various fields. In this study, we have used Optimized Inference Intelligence System namely ANFIS-PSO which is a combination of Adaptive Neural-Fuzzy Inference System (ANFIS) and Particle Swarm Optimization (PSO) for the estimation of shear strength parameters of the soils (Cohesion “C” and angle of internal friction “φ”). These parameters are required for designing the foundation of civil engineering structures. Normally, shear parameters of soil are determined either in the field or in the laboratory which require time, expertise and equipments. Therefore, in this study, we have applied a hybrid model ANFIS-PSO for quick and cost-effective estimation of shear parameters of soil based on the other six physical parameters namely clay content, natural water content, specific gravity, void ratio, liquid limit and plastic limit. In the model study, we have used data of 1252 soft soil samples collected from the different highway project sites of Vietnam. The data was randomly divided into 70:30 ratios for the model training and testing, respectively. Standard statistical measures: Root Mean Square Error (RMSE), Mean Absolute Error (MAE) and Correlation Coefficient (R) were used for the performance evaluation of the model. Results of the model study indicated that performance of the ANFIS-PSO model is very good in predicting shear parameters of the soil: cohesion (RMSE = 0.075, MAE = 0.041, and R = 0.831) and angle of internal friction (RMSE = 0.08, MAE = 0.058, and R = 0.952).

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 The Influence of Compaction and Water Conditions on Shear Strength and Friction Resistance between Geotextiles and Ash-Slag Mixture

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1086
Author(s):  
Andrzej Gruchot ◽  
Tymoteusz Zydroń ◽  
Agata Michalska
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Water Saturation ◽  
Friction Angle ◽  
Interaction Coefficient ◽  
Interfacial Friction ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Angle Of Internal Friction ◽  
Friction Resistance

The paper presents the results of tests of the shear strength of the ash–slag mixture taken from the landfill located in Kraków (Poland) and the interfacial friction resistance at the contact between the ash–slag mixture and woven or nonwoven geotextiles. The tests were carried out in a direct shear apparatus on samples with and without water saturation. The samples for testing were formed in the apparatus box at the optimum moisture by compacting them to IS = 0.90 and 1.00. The test results reveal that the shear strength parameters of the ash-slag mixture were large. It was stated the significant influence of the compaction, the growth of which has resulted in an increase in the angle of internal friction (from 7% to 9%) and cohesion (from 60% to 97%). Whereas the saturation of the samples reduced the shear strength parameters (from 4% to 6%, of the internal friction angle and 30% to 43% of cohesion). The values of the interfacial friction resistance at the contact between the ash–slag mixture and the geotextiles were large as well, but slightly smaller than the values of the shear strength parameters of the mixture itself. The compaction caused an increase in the angle of interfacial friction (from 1% to 5%) and adhesion (from 31% to 127%). The water-saturation of the samples caused a change in the angle of interfacial friction (from −6% to 3%) and decline in the adhesion (from 22% to 69%). Values of the interaction coefficient were about 0.8–1.0 and they tended to rise with increasing the normal stress. Higher values of this parameter were obtained in tests with water saturation and for non-woven geotextiles.

The influence of grain size and frictional/cohesional shear strength components on UK salt marsh substrate stability

2020 ◽  
Author(s):  
Helen Brooks ◽  
Iris Moeller ◽  
Tom Spencer ◽  
Kate Royse
Keyword(s):  
Shear Strength ◽  
Salt Marsh ◽  
Internal Friction ◽  
Water Levels ◽  
Systematic Research ◽  
Surface Erosion ◽  
Marsh Edge ◽  
Angle Of Internal Friction ◽  
Erosion Processes ◽  
Ring Shear

<p>Salt marshes attenuate waves and currents, thus protecting landward-lying constructed defences and the hinterland from incoming waves and extreme water levels. As such, understanding the stability of the marsh sedimentary platform is important, particularly as marsh edge erosion is common on many shores. To understand why marshes are losing material from their exposed fringes, we must better understand the relations between the marsh fabric and incoming hydrodynamic energy; this is likely to be strongly influenced by marsh biological, geochemical and sedimentological/geotechnical properties. Currently there is little systematic research into the within- and between-marsh variability in these properties and how they affect both marsh edge and marsh surface erosion processes.</p><p> </p><p>We compare Tillingham marsh, eastern England, where the sediment is clay/silt-dominated and the marsh canopy is species-rich, to Warton marsh, Morecambe Bay, NW England, where the sediment is sand/silt-dominated and the vegetation species-poor. We determine soil shear strength by applying geotechnical methods which, to the best of our knowledge, have not previously been applied to salt marsh environments. Shear box and ring shear tests are used to determine the natural- and residual (i.e. post-failure) shear strength of the substrate, respectively. This is expressed as the cohesion of the sediment and the angle of internal friction. We demonstrate that the ring shear test consistently returns a lower angle of internal friction for the substrate, which is expected for the residual angle of internal friction. However, we are also able to link this reduction in the angle of internal friction to substrate composition (e.g. root content, organic matter and particle size distribution). This enhanced methodological understanding will improve our comprehension of marsh resistance to edge erosion and thus our ability to predict future erosion. Ultimately, accurate measurements of the shear strength of natural foreshores are essential for the informed implementation of nature-based coastal flood defences, including ‘de-embankment’/‘managed realignment’ schemes.</p>

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.

Experimental Study on the Effect of Water on Shear Strength Characteristic of Shale

2013 ◽  
Vol 816-817 ◽  
pp. 153-160
Author(s):  
Jian Liu ◽  
Shang Ge Liu ◽  
Xiao Tao
Keyword(s):  
Shear Stress ◽  
Shear Strength ◽  
Internal Friction ◽  
Strength Characteristic ◽  
Natural State ◽  
Displacement Curve ◽  
Angle Of Internal Friction ◽  
Failure Characteristic ◽  
Effect Of Water ◽  
Water Saturated

In order to understand the shear strength characteristic of water-sensitive shale under the effect of water in the northwest of Hubei province, we carried out direct shear tests of shale in natural and water-saturated states along its bedding plane with original shale samples taken from the Guzhu expressway and analyzed the shear stress-displacement relationship under different normal stresses and explored the influence of water on shale shear deformation and strength characteristic. This study shows that the shear stress-displacement curve of shale in natural state and water-saturated state presents significant similarities and differences; compared with natural shale, water-saturated shale witnesses an obvious drop in its cohesive force, internal friction angle and residual angle of internal friction; shale in natural state presents apparent brittle failure characteristic while water-saturated shale to some extent exhibits ductile failure characteristic.

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