IMPROVEMENT OF EXPANSIVE SOIL BY ELECTRO-KINETIC METHOD

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Tran Thi Thanh Thuy ◽  
Doni Prakasa Eka Putra ◽  
Wawan Budianta ◽  
Hemanta Hazarika
Keyword(s):  
Shear Strength ◽  
Calcium Chloride ◽  
Pure Water ◽  
Expansive Soil ◽  
Soil Improvement ◽  
Undrained Shear Strength ◽  
Soil Samples ◽  
Atterberg Limits ◽  
Engineering Properties ◽  
Undrained Shear

The roadway in Karangjati, Ngawi Regency, East Java, Indonesia, which is underlain by expansive soil, is susceptible to damage due to volume change. This research aims to improve the engineering properties, such as consistency limits, compressibility, and undrained shear strength of the montmorillonite dominated soil in this area using an electrokinetic stabilization method. Four electro-kinetic experiments were conducted using different electrolytes (calcium chloride or pure water) under different conditions (no-flow or flow water). The results show that, pH values of all soil samples decreased at anolyte and increased at catholyte. Atterberg limits of the soil samples were found to increase, where the liquid limit (LL) range of 79.72– 86.14%, plastic limit (PL) 25.22–30.80%, and plasticity index (PI) 53.28–60.92, liquidity Index (LI) 0.91–1.08. The compression index Cc was 0.50– 0.742. Undrained shear strength of treated soil range of 7–11 kPa. Moreover, strengthening degree of the treated soils achieve 304–556%. The soil improvement was achieved by decreasing the Atterberg limits, and compressibility and increasing the undrained shear strength. Applying calcium chloride and flow water condition were the most effective methods for the soil improvement. The mineralogical compositions of the soil samples did not change after the treatment. Keywords: Electro-kinetic stabilization, electro chemical injection, clayey soil improvement.

Shear strength of remolded soils at consistency limits

2010 ◽  
Vol 47 (3) ◽  
pp. 259-266 ◽  
Author(s):  
Kamil Kayabali ◽  
Osman Oguz Tufenkci
Keyword(s):  
Shear Strength ◽  
Linear Relationship ◽  
Water Content ◽  
Undrained Shear Strength ◽  
Liquid Limit ◽  
Soil Samples ◽  
Atterberg Limits ◽  
Plastic Limit ◽  
Water Contents ◽  
Undrained Shear

The undrained shear strength of remolded soils is of concern in certain geotechnical engineering applications. Several methods for determining this parameter exist, including the laboratory vane test. This study proposes a new method to estimate the undrained shear strength, particularly at the plastic and liquid limits. For 30 inorganic soil samples of different plasticity levels, we determined the Atterberg limits, then performed a series of reverse extrusion tests at different water contents. The plastic and liquid limits are derived from the linear relationship between the logarithm of the extrusion pressure and water content. The tests show that the average undrained shear strength determined from the extrusion pressures at the plastic limit is about 180 kPa, whereas the average undrained shear strength at the liquid limit is 2.3 kPa. We show that the undrained shear strength of remolded soils at any water content can be estimated from the Atterberg limits alone. Although the laboratory vane test provides a reasonable undrained shear strength value at the plastic limit, it overestimates the undrained shear strength at the liquid limit and thus, care must be taken when the laboratory vane test is used to determine undrained shear strengths at water contents near the liquid limit.

The Influence of Dehumidifying Condition on Expansive Soil Engineering Properties

2012 ◽  
Vol 594-597 ◽  
pp. 487-492
Author(s):  
Xiong Wei Li ◽  
Ai Jun Wang ◽  
Guo Zhong Dai
Keyword(s):  
Shear Strength ◽  
Relative Humidity ◽  
Water Content ◽  
Expansive Soil ◽  
Expansion Ratio ◽  
Soil Samples ◽  
Engineering Properties ◽  
Drying Rate ◽  
Initial Water Content ◽  
Initial Water

The expansive soil behaviour of expansive deformation and shear strength is deeply influenced by humidity condition. Different soil drying rate was set with constant temperature and different relative humidity. When saturated soil samples was dried to the different predetermined water content, the expansion ratio test with the upper load was made. It is shown that in the condition of high relative humidity, the expansion ratio is high. The smaller initial water content and upper load may lead to a larger swelling deformation. When soil samples with different initial water content was fully expanded, the consolidated direct shear tests were made. It is shown that the smaller drying rate leads to the greater shear strength after full expansion. What’s more, the upper load may improve the soil shear strength.

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.

scholarly journals Prediction of Undrained Shear Strength of Crushed Tire Mixture with Fine-Grained Soil by using Machine Learning Approaches

2021 ◽  
Author(s):  
Chia Zarei ◽  
parveen sihag ◽  
Leila Rahimi
Keyword(s):  
Shear Strength ◽  
Specific Gravity ◽  
Undrained Shear Strength ◽  
Soil Samples ◽  
Vertical Stress ◽  
Waste Material ◽  
Support Vector ◽  
Data Set ◽  
Testing Stage ◽  
Undrained Shear

Abstract This research examines the ability of soft computing approaches (i.e. Linear Regression (LR), Gaussian Process regression (GP), Adaptive neuro-fuzzy inference system (ANFIS),Support Vector Machine (SVM) and deep neural network (DNN)) to predict the undrained shear strength (SU) of soil mixed waste crushed tires. Data set consisting of 72 different samples were used and obtained from the laboratory experiments. Out of 72 experimental observations randomly separated 50 observations were selected for model development whereas residual 22 were selected for the validation of the developed models. Input data set consist of vertical stress, percentage of the crushed tire, percentage of clay, size of clay, specific gravity of tires, Liquid limit, Plastic limit and Specific gravity of clay samples were considered as inputs whereas undrained shear strength of stabilized soil using waste crushed tires material (SU) was considered as output. Five most popular goodness fit assessment parameters were used for the comparison among developed models. Results suggest that DNN based model works superior to other developed models for the prediction of SU the soil samples mixed with tires waste material with coefficient of correlation values as 0.9975, 0.9736, Root mean square error values as 2.4198, 7.5319, Mean absolute error values as 1.8407, 6.1870, Scatter index values as 0.0311, 0.0959 and Nash Sutcliffe model efficiency values as 0.9943, 0.9387 for training and testing stage respectively. Sensitivity analyses offer that specific gravity of tires, size of clay and vertical stress were the most influencing variables in the prediction SU the soil samples mixed with tires waste material.

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 Strength Properties of Reinforced Peat Using Fiber-Polyester and Shredded Rubber-Crumb as Reinforcement Material

2018 ◽  
Vol 7 (3.18) ◽  
pp. 26
Author(s):  
Norazzlina M.Sa’don ◽  
Abdul Razak Abdul Karim ◽  
Siti Noor Linda Taib ◽  
Mahshuri Yusof
Keyword(s):  
Shear Strength ◽  
Waste Disposal ◽  
Strength Properties ◽  
Undrained Shear Strength ◽  
Engineering Properties ◽  
Rubber Crumb ◽  
Fiber Reinforced ◽  
Effective Contact ◽  
Strength Improvement ◽  
Undrained Shear

This paper presents an investigation of the strength improvement of reinforced peat by using the fiber reinforcement techniques of the lightweight waste material, i.e., tire-waste disposal. The fiber-polyester and shredded rubber crumb are extracted and process for the collected tire-waste disposal. In this study, the fiber-polyester and shredded rubber-crumb are mixed with peat (Pt), with undrained shear strength, cu of <10 kPa and 5 % cement content, which act as a binder. The peat samples are mixed at various percentages of fiber-polyester and shredded rubber-crumb. The compacted fiber-reinforced peat samples were prepared at optimum moisture content, mixes thoroughly to a uniform condition by laboratory mixer and air cured for 7 and 28 days in a single batch. The strength improvement of undrained shear strength, cu of >100 kPa is targeted at minimal percentages of cement added. The Unconfined Compression Strength (UCS) and California Bearing Ratio (CBR) tests are performed for determination of the engineering properties of fiber-reinforced peat. Based on the results obtained, one can be seen that both fiber-polyester and shredded rubber crumb shows an increment in unconfined compressive strength value of 214 kPa and 55 kPa, respectively. In summary, the study shown that, the inclusion of fiber-polyester and shredded rubber-crumb from tire-waste disposal increased the effective contact area between reinforced material and peat, which then improved the strength significantly, and the used of tire-waste disposal for the construction may not only provide the alternative mean of recycling and reusing, however, it also addressed economic and environmental concerns and reduce construction cost by making the best use of locally available materials.  

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