scholarly journals Some Geotechnical Properties of Plastic Soil Enhanced with Cement Dust

2021 ◽  
Vol 27 (10) ◽  
pp. 20-33
Author(s):  
Abeer F. Hussein ◽  
Ahmed S. Ali ◽  
Abbas J. Al-Taie
Keyword(s):  
Shear Strength ◽  
Dry Weight ◽  
Undrained Shear Strength ◽  
Geotechnical Properties ◽  
Cement Kiln ◽  
Compression Tests ◽  
Cement Dust ◽  
Engineering Structures ◽  
Soil Cement ◽  
Undrained Shear

Plastic soil exhibits unfavorited geotechnical properties (when saturation), which causes negative defects to engineering structures. Different attempts (included various materials) were conducted to proffer solutions to such defects by experimenting in practical ways. On one hand, these attempts aimed to improve the engineering characteristics of plastic soil, and on the other hand, to use problematic waste materials as a stabilizer, like cement kiln dust, and to reduce environmental hazards. This paper explored the shrinkage, plasticity, and strength behavior of plastic soil enhanced with cement dust. The cement dust contents were 0%, 5%, 10%, 15% and 20% by dry weight of soil. An experimental series of shrinkage and plasticity tests and unconfined compression tests were carried out to explore the effects of cement dust on the quantitative amount of shrinkage, plasticity characteristics, and shear strength experienced by plastic soil. The effects of curing on soil strength were also investigated. The finding of this paper showed that the critical behavior and plasticity of plastic soil could be reduced by mixing the soil with 15% or 20% of cement dust. The undrained shear strength, cu, of plastic soil-cement dust mixtures increased with the increasing dust content up to 20%. In fact, this strength was affected by the curing period. The best enhancement was attained when the content of cement dust was 20%, and the undrained shear strength was increased more than three times at this content.

scholarly journals Shrinkage and Strength Behavior of Highly Plastic Clay Improved by Brick Dust

2020 ◽  
Vol 26 (5) ◽  
pp. 95-105
Author(s):  
Ali F. Al-Baidhani ◽  
Abbas J. Al-Taie
Keyword(s):  
Shear Strength ◽  
Dry Weight ◽  
Undrained Shear Strength ◽  
Engineering Properties ◽  
Compression Tests ◽  
Engineering Structures ◽  
Plastic Clay ◽  
Strength Behavior ◽  
Undrained Shear ◽  
Brick Dust

Highly plastic soils exhibit unfavorited properties upon saturation, which produce different defects in engineering structures. Attempts were made by researchers to proffer solutions to these defects by experimenting in practical ways. This included various materials that could possibly improve the soil engineering properties and reduce environmental hazards. This paper investigates the strength behavior of highly plastic clay stabilized with brick dust. The brick dust contents were 10%, 20%, and 30% by dry weight of soil. A series of linear shrinkage and unconfined compression tests were carried out to study the effect of brick dust on the quantitative amount of shrinkage experienced by highly plastic clay and the undrained shear strength. The effect of curing on soil shear strength was included in this paper. It was found that the critical behavior of highly plastic soil can be mitigated by mixing with 20% or 30% of brick dust. The undrained shear strength of highly plastic clay mixed with brick dust increased with the increase of brick dust content up to 20%. It was affected by the curing period. The best improvement was achieved when the optimum content of brick dust was 20%. Finally, seven days of curing improved the undrained shear strength with over 100%.

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.

The 2nd Hanrahan Lecture: Geotechnical properties of Irish compressible soils

2020 ◽  
Vol 53 (4) ◽  
pp. 475-522
Author(s):  
Michael Long
Keyword(s):  
Shear Strength ◽  
Undrained Shear Strength ◽  
Geotechnical Properties ◽  
Rapid Rate ◽  
Soft Soils ◽  
Micro Scale ◽  
Ground Investigation ◽  
The Future ◽  
Work Done ◽  
Undrained Shear

The objectives of this paper are to provide an update on work done and the development of knowledge on Irish compressible soils since Eamon Hanrahan's book on the topic. Eamon subdivided these soils into three categories; namely, alluvial, estuarine and lake-bed deposits, and he termed them ‘troublesome soils’. A brief background geology will initially be presented. The complexity of the deposits both on a macro- and micro-scale will be highlighted. Sites that have been well studied will be summarized and the engineering solutions used to construct on these sites will be reviewed. Although work on these sites presents a significant engineering achievement, some important lessons were learned. The remainder of the paper deals with how these lessons might be addressed in the future; for example, how to use modern ground investigation techniques to best characterize these complex deposits and what are the best techniques for examining important detailed aspects of 1D consolidation behaviour such as the identification of the apparent preconsolidation stress, the sometimes rapid rate of consolidation and creep, and also how to characterize the undrained shear strength of the soils. The work will be benchmarked against experience of the behaviour of Scandinavian soft soils.

scholarly journals Interpretation of undrained shear strength observed in confined triaxial compression tests on compacted clay

2021 ◽  
Author(s):  
Chee K. Wong ◽  
Martin Lun ◽  
Ron C.K. Wong
Keyword(s):  
Shear Strength ◽  
Unsaturated Soil ◽  
Water Pressure ◽  
Triaxial Compression ◽  
Undrained Shear Strength ◽  
Compacted Clay ◽  
Compression Tests ◽  
Basic Model ◽  
Triaxial Compression Tests ◽  
Undrained Shear

This paper presents an interpretation technique to quantify the effects of compaction state and matric suction on the undrained shear strength of compacted clay under confined undrained triaxial compression. This novel technique is based on the mathematical frameworks of SHANSEP (Stress History and Normalized Soil Engineering Property) method for saturated soil and BBM (Barcelona Basic model) for unsaturated soil. Test data of compacted Calgary till were analyzed and interpreted using the proposed technique. The interpretation technique is very useful in delineating the relative impacts of the factors on the behavioral trends in measured undrained shear strength. It was found that in addition to the initial compacted void ratio and suction, soil structure and failure mode exert significant influence on the undrained shear strength of compacted clay. This technique is attractive to engineering practitioners because the confined undrained compression tests (with no pore air and water pressure measurement) are much simpler and less time consuming compared to rigorous laboratory tests on unsaturated soil.

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.

Effects of Electro Osmotic Consolidation in South West of Johor: Small Laboratory Scale

2014 ◽  
Vol 803 ◽  
pp. 255-264
Author(s):  
Khairul Nizar Mohd Yusof ◽  
Fauziah Ahmad ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Muhammad Faheem Mohd Tahir
Keyword(s):  
Shear Strength ◽  
Water Content ◽  
Clay Soil ◽  
Soft Clay ◽  
Soil Improvement ◽  
Undrained Shear Strength ◽  
Engineering Structures ◽  
Vertical Loading ◽  
South West ◽  
Undrained Shear

Clay soil is one of the problematic soils due to its natural states which have low bearing capacity and high compressibility. The effect and problem of the clay soil characteristic creates a problem for construction especially excessive settlement and this can lead to unstable and potential cracks of engineering structures. At presents, there are few of soil improvement types can be carried out to overcome these problems, and electro osmotic consolidation is one of the options. This method has been applied many years ago especially in european countries. The study encompasses the determination of water content, atterberg’s limits and undrained shear strength after electro osmotic consolidation treatment of clay soils taken from 0.5 m and 1.5 m at southwest part of johor. All the samples were tested according to BS1377:1990. An experimental study was implemented in a pvc cylinder tube having dimensions of 300 mm height and 100 mm diameter. In the results of electro osmotic consolidation tests by installing copper spring electrodes, the measured undrained shear strength was increased considerably at the anodes especially compared to the initial undrained shear strength due to electro osmosis process and consolidation. As laboratory studies of its measurement have shown, the application of electro osmotic consolidation after the application of a direct current applied voltage of 10 volts, at the anodes especially: (i) a decrease by approximately 35% in water content; (ii) an increase around 29% in undrained shear strength; and (iii) a decrease about 21% in index plasticity. The results obtained in this study shows that the electro osmotic enhanced 15 kpa vertical loading consolidation is a feasible approach in strengthening of south west soft clay in johor. It can be clearly suggested that the higher the voltage applied in the system, the higher readings of undrained shear strength and the lower of water content especially at the anodes.

Geotechnical properties of soft clays from the Witch Ground Basin, central North Sea

1991 ◽  
Vol 7 (1) ◽  
pp. 151-156 ◽  
Author(s):  
M. A. Paul ◽  
L. M. Jobson
Keyword(s):  
Shear Strength ◽  
Undrained Shear Strength ◽  
Geotechnical Properties ◽  
Seismic Surveys ◽  
Soft Clays ◽  
Fine Grained ◽  
Acoustic Signatures ◽  
The Witch ◽  
Central North Sea ◽  
Undrained Shear

AbstractThe Witch Ground Basin to the northeast of Peterhead is occupied by Late to Postglacial clays which reach a maximum thickness of over forty metres. High resolution seismic surveys have shown that the Sediments can be divided into two stratigraphic units on the basis of their acoustic signatures: the upper Witch Ground Formation shows in its lower part a finely detailed pattern of laterally continuous multiple reflectors, whereas the lower Swatchway and Coal Pit Formations present a disorganised signature in which few reflectors are continuous.Profiles of bulk density, water content and undrained shear strength have been obtained from two continuously sampled, adjacent boreholes which penetrated the sediments to a depth of forty metres. These show that the deposits of the Witch Ground Basin comprise a single geotechnical unit with the properties expected of a fine grained sediment of glaciomarine origin. The principal geotechnical properties change gradationally as a result of changes in composition and from selfweight compression. The different seismic signatures on which the basin stratigraphy is based are not reflected by major geotechnical changes within the sediment, but may well result from secondary features of the geotechnical profile.

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.

scholarly journals Improving geotechnical properties of clayey soil using polymer material

2018 ◽  
Vol 162 ◽  
pp. 01002 ◽  
Author(s):  
Hussein Karim ◽  
Kawther Al-Soudany
Keyword(s):  
Shear Strength ◽  
Polymer Material ◽  
Clayey Soil ◽  
Undrained Shear Strength ◽  
Geotechnical Properties ◽  
Fiber Content ◽  
Strength Parameter ◽  
Polymer Content ◽  
Polymer Fiber ◽  
Undrained Shear

This study illustrates the application of polymer material for clayey soil stabilization. The article will focus on studying the strength behavior of the clayey soils reinforced with homogenously polymer fiber. In the current research, “polypropylene” was selected as polymer material to reinforce the natural clay soil. This polymer fiber was added to the clayey soil with four different percentages of (0, 1.5, 3, and 5%) by weight of soil. Various tests with different polymer contents were performed to study the effect of using such a polymer as a stabilizing agent on geotechnical properties of clay. As the fiber content increases, the optimum moisture content (OMC) is increased while the specific gravity decreases. For Atterberg’s limits, the results indicated increasing liquid limit and plasticity index while decreasing plastic limit with increase in polymer content. The outcomes of the tests also reflected a considerable improvement in the unconfined compressive strength with noticeable improvement in the shear strength parameter (undrained shear strength, cu) of the treated soils. The undrained shear strength obtained from treated soil with 5% polymer addition is more than three times that of the untreated soil. With an increase in polymer content, the consolidation parameters (Compression index Cc and recompression index Cr) decreases. Finally, the benefit of the reinforcement is increased with increasing polymer fiber content.

scholarly journals Consolidated Undrained Triaxial Compression Tests and Strength Criterion of Solidified Dredged Materials

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Jianwen Ding ◽  
Xusong Feng ◽  
Yupeng Cao ◽  
Sen Qian ◽  
Feng Ji
Keyword(s):  
Shear Strength ◽  
Water Pressure ◽  
Triaxial Compression ◽  
Strength Criterion ◽  
Undrained Shear Strength ◽  
Compression Tests ◽  
Dredged Materials ◽  
Strength Evolution ◽  
Triaxial Compression Tests ◽  
Undrained Shear

Consolidated undrained triaxial compression tests were performed to investigate the shear strength behavior of the solidified dredged materials (SDM). The variation law of deviator stress and excess pore water pressure with the increase of the applied confining pressure was investigated. It is found that the shear strength envelope is consisted of two lines, and there exists a transitional stress on the intersection point. The undrained shear strength develops slightly with the increase of applied normal stress in the preyield state. However, the undrained shear strength increases significantly in the postyield state, and the strength envelope is nearly a straight line with the extension through the origin. Based on the triaxial test data and the binary medium model, a strength criterion considering strength evolution mechanism is proposed and the relevant parameters of the strength criterion were discussed. Comparisons of the predicted results and experimental data demonstrate that the proposed strength criterion can properly describe the strength evolution rules of the SDM.

Sign in / Sign up

Export Citation Format

Share Document