Papers by zalihe nalbantoglu
Canadian Geotechnical Journal, 2001
Arabian Journal of Geosciences
Geotechnical Testing Journal, 2002
The calcareous expansive soil in Cyprus has caused serious damage to structures. High-quality Som... more The calcareous expansive soil in Cyprus has caused serious damage to structures. High-quality Soma fly ash admixture has shown tremendous potential as an economical method for the stabilization of the soil. Fly ash and lime-fly ash admixtures reduce the water absorption capacity and compressibility of the treated soils. Unlike some of the previously published research, an increase in hydraulic conductivity of the treated soils was obtained with an increase in percent fly ash and curing time. X-ray diffractograms indicate that pozzolanic reactions cause an alteration in the mineralogy of the treated soils, and new mineral formations with more stable silt-sand-like structures are produced. In the present study, an attempt has been made to use cation exchange capacity (CEC) values to substantiate the findings that, with increasing percentage of fly ash and curing time, soils become more granular in nature and show higher hydraulic conductivity values.
Acta Geotechnica Slovenica, 2021
Soft soils have a high compressibility, and low shear strength, and constructions on such soils o... more Soft soils have a high compressibility, and low shear strength, and constructions on such soils often require the use of ground-improvement techniques. This paper compares the use of an electrokinetic (EK) treatment of soft soils using the ionic solutions calcium chloride and sodium carbonate. The effects of the ionic-solution type, the EK-treatment duration, the cation exchange capacity (CEC), the specific surface area (Sa), the pH, the electrical conductivity (σ), and the ionic strength (Is) were considered in this study. Examining the parameters and evaluating their effects on soil behavior are difficult and complex. The design of experiments (DOE) software program was used to evaluate the effects of the parameters and determine the significant input factors for the EK treatment on soft soils. The analysis and optimization of the data produced the threshold values using the design-expert® software. In this study, the EK-treated soil with CEC = 4.9 meq 100/g, Sa = 4.5 m2/g , pH = ...
Springer Series in Geomechanics and Geoengineering, 2018
The electrokinetic (EK) treatment is proven to be an effective method in laboratory and field sca... more The electrokinetic (EK) treatment is proven to be an effective method in laboratory and field scale studies. The EK technique has lots of drawbacks such as electrode corrosion, cell setup, uncertain energy usage and cost, loss of energy with time, choice of materials, and no standard procedures. The metal electrodes corroded rapidly over a short period of time, cause voltage loss, reduce energy efficiency, and contaminate soil, thus, result in complexity and variability within the test system. Thus, EK method is seldom used as an alternative soil treatment with its enormous potentials. This paper discusses the challenges, potential remedies, and recommendations for EK technique, such as using a sacrificial anode to prevent, control or minimize the corrosion of the electrodes. The choice of electrodes is significant in improving the index and engineering properties of the soil and prevent the electrode corrosion or contamination of the soil, control variability and maintaining the electrical efficiency of the system. This implies that cheap and available metals can be used effectively in EK technique, both in the laboratory and in-situ bench-scale studies.
Marine Georesources & Geotechnology, 2021
World Academy of Science, Engineering and Technology, International Journal of Geotechnical and Geological Engineering, 2016
Arabian Journal for Science and Engineering, 2021
European Journal of Environmental and Civil Engineering, 2020
Arabian Journal for Science and Engineering, 2020
Stone columns have become a widely used method of increasing bearing capacity of soft soils. This... more Stone columns have become a widely used method of increasing bearing capacity of soft soils. This study investigates floating stone columns with and without encasement in soft soils. Although the stone columns in single-layered soil have been studied extensively, stone columns constructed in a base of varying soil layers are not fully understood. In the present study, the behavior of both single-layered soft soil and layered soil consisting of loose sand overlaying the soft soil was investigated by using small-scale laboratory pilot tests. The bearing capacity of soft soil was improved in all cases of stone column application. The contribution of stone columns on the bearing capacity of soft soil was presented by the term bearing improvement ratio (BIR). With a non-encased stone column in single-layered soft soil, the BIR was about 3.3-fold and with geotextile encasement in the same soil, the improvement ratio increased to 3.4-fold. For a non-encased stone column in layered soils, the BIR was about 2.0-fold and with geotextile enhancement in the same soil, this improvement ratio increased to 4.0-fold. The inclusion of geotextiles resulted in improved bearing capacity by distributing the induced stresses over larger areas. The maximum bulging of non-encased stone column in single-layered soft soil was observed at the depth of 1.5 times the original diameter of the stone column from the top, whereas for encased stone column in single-layered soft soil, the maximum bulging was transferred to a depth of 3.0 times the original diameter of the stone column.
SN Applied Sciences, 2019
Recycling plastic waste from water bottles has become one of the main challenges worldwide. The a... more Recycling plastic waste from water bottles has become one of the main challenges worldwide. The aim of this study is to recycle empty plastic water bottles as reinforcing material for the improvement of sandy soil. The laboratory tests were performed on both natural and reinforced sands with different plastic waste percentages: 0, 0.5, 0.75 and 1.0 of the dry weight of sand at relative density states of 30% and 60%. Direct shear box and the California Bearing Ratio, CBR tests were performed to determine the effect of the plastic waste on the shear strength and the penetration resistance of the reinforced sand. Test results indicated that plastic waste reinforcement contributed to the improvement of the shear strength and the CBR number of the reinforced sand. Higher shear strength and higher penetration resistance were obtained with plastic waste reinforcement. The optimum percentage of plastic waste required for enhancing the shear strength and the CBR number was found to be 0.75%. With the optimum percentage of plastic waste, the improvement in the shear strength and the penetration resistance of the reinforced sand increased to at least 9% compared to natural soil at relative density states of 30% and 60%.
Environmental Geotechnics, 2019
Ahead of Print articles will move to that issue's Table of Contents. When the article is publishe... more Ahead of Print articles will move to that issue's Table of Contents. When the article is published in a journal issue, the full reference should be cited in addition to the DOI.
Marine Georesources & Geotechnology, 2016
In this study, research was conducted to examine the performance of the lime pile application, a ... more In this study, research was conducted to examine the performance of the lime pile application, a deep chemical stabilization method to improve the engineering characteristics of marine soil deposits. By using a laboratory scale model, the marine soil sample was compacted into soil blocks in circular steel test tanks, with the installation of lime piles in them. An experimental program examined the effect of the lime piles on the physical and engineering properties of the soil in terms of curing periods and lime pile radial distances. Test results showed that the clay fines, linear shrinkage, compressibility and swelling pressure decreased, while the permeability, preconsolidation pressure, and stiffness increased significantly with an increase in curing periods and within a close distance to the lime piles. Also, the electrical resistivity of the treated soils was examined to monitor the changes in their electrical properties. Finally, the correlation between the measured electrical resistivity and swell pressure values of the tested soils at Marine Georesources & Geotechnology 2 different curing periods suggested that the electrical resistivity values can be used as a monitoring technique for the deep chemical treatments of the subsurface soil.
Mathematical Problems in Engineering, 2015
Wave propagation in an unbounded domain surrounding the stimulation resource is one of the import... more Wave propagation in an unbounded domain surrounding the stimulation resource is one of the important issues for engineers. Past literature is mainly concentrated on the modelling and estimation of the wave propagation in partially layered, homogeneous, and unbounded domains with harmonic properties. In this study, a new approach based on the Finite Point Method (FPM) has been introduced to analyze and solve the problems of wave propagation in any nonhomogeneous unbounded domain. The proposed method has the ability to use the domain properties by coordinate as an input. Therefore, there is no restriction in the form of the domain properties, such as being periodical as in the case of existing similar numerical methods. The proposed method can model the boundary points between phases with trace of errors and the results of this method satisfy both conditions of decay and radiation.
In recent years, the contamination of subsurface soils and groundwater from landfills, industrial... more In recent years, the contamination of subsurface soils and groundwater from landfills, industrial activities, and other sources has been receiving more attention and has created an urgent need to find feasible solutions to the problem. In this regard, examining the influence of chemical contaminants on geotechnical properties of clays and understanding the underlying mechanisms is important. In order to define the effects of organic liquids on clay soil, ethylene glycol which is generally found in petroleum contaminated sites was selected in this study. Ethylene glycol, with a medium dielectric constant of 37.7 was mixed with different percentages by the volume of distilled water and used in geotechnical tests. Atterberg limit tests were performed in order to determine the effect of different percentages of ethylene glycol on consistency of the soil. Swelling tests were also performed to evaluate the changes in the swell potential of the clay soil permeated with different percentages of ethylene glycol. Results of the investigation indicated that increase in the concentration of pore fluid resulted in a decrease in the dielectric constant which conduced to a decrease in the diffuse double layer thickness. Depression of the diffused double layer resulted in a decrease in the plasticity of the soil and hence decrease in the swelling potential of the soil was observed. Test results showed that organic chemicals caused less heaving in soils compared with distilled water.
Canadian Geotechnical Journal, 2015
Soil improvement is one of the basic requirements for preparing in situ soils for appropriate str... more Soil improvement is one of the basic requirements for preparing in situ soils for appropriate strengthening, stiffness, and stability in civil engineering designs and applications. The modification technique, which involves mechanical, thermal, and chemical components, requires monitoring techniques to determine its efficiency and suitability. This study examines the geotechnical improvement of clay soils using the lime pile technique on a laboratory-scale model. The clay–lime physicochemical reactions resulting from cation exchange were examined through basic experimental analyses. In addition, electrical conductivity measurements were performed on the selected treated soils to examine variations in their electrical properties. Remolded compacted clay soil blocks were carefully prepared in circular steel test tanks with lime piles installed in them. The treated soil block properties were then investigated as a function of radial lime pile distances and curing periods. It was observ...
Proceedings of the International Conference on Ground Improvement & Ground Control, 2012
Electrokinetic is the movement of ions, charged solid particles and water between two electrodes ... more Electrokinetic is the movement of ions, charged solid particles and water between two electrodes under the influence of an electrical field. Electrokinetic can be applied to the fields such as stabilization of soft soils and slopes, decontamination of pollutants, and sealing and leak-detection system of geomembrane, etc. The aim of this study was to evaluate the use of electrokinetic as an effective method to strengthen the soft clay soil with high compressibility. An in situ soil treatment technique using the principles of electrokinetic was tested using laboratory experimental models. The effectiveness of this approach in stabilizing and improving the physical properties of soft clay was tested and examined. In the study, soil specimens were compacted in glass tanks to reproduce in-situ density and in-situ water content. Mild steel electrodes were inserted into the soil and a direct current was passed through the soil under a constant potential gradient of 35-60 Volts for a period of 14 days. Distilled water and saturated lime solutions were introduced to the soil from anode to cathodes over the testing period. The physical and index properties of the soft clay were tested before and after the electrokinetics stabilization and the results were discussed. Test results indicated that introducing lime into the soil by electrokinetic method reduced the plasticity index of the soil and resulted in a lower compressibility of the soft clay. Treatment of soil by electrokinetic method enabled the measurement of the compressive strength of the soil which resulted in an increase in soil's strength.
Waste Management & Research, 2012
Penetration of hazardous liquids through waste containment barriers exerts contamination and cons... more Penetration of hazardous liquids through waste containment barriers exerts contamination and considerable alterations in geotechnical properties of clay liners. In general, these changes are attributed to the variation of the dielectric constant and the chemistry of the pore fluids which cause changes in soil structure. In the present study, a series of laboratory tests were performed on natural and contaminated clay soil permeated with different hazardous liquids: ethylene glycol and toluene which are generally found in petroleum-contaminated sites, possessing intermediate and low dielectric constants. Toluene was used in its pure form and ethylene glycol was used at various percentages of 0, 20, 40 and 60% by the volume of distilled water. In addition, natural sea water was also utilized as an inorganic fluid for permeation and salinization of the clay soil. The overall test results indicated that plasticity, sedimentation time, unconfined compressive strength, swell and compressi...
International Journal of Mining, Reclamation and Environment, 2011
Penetration of organic liquids through the soil causes contamination and considerable changes in ... more Penetration of organic liquids through the soil causes contamination and considerable changes in the geotechnical properties of soils. In general, these changes are attributed to variations in the dielectric constant and chemistry of the pore fluids, which result in several changes in soil behaviour. For this reason, it is necessary to investigate the geotechnical properties of contaminated soils for engineering
Clay Minerals, 1996
The use of ground granulated blast furnace slag (ggbs) is well established in many cement applica... more The use of ground granulated blast furnace slag (ggbs) is well established in many cement applications where it provides enhanced durability, including high resistance to chloride penetration, resistance to sulphate attack and protection against alkali silica reaction (ASR). The use of ggbs in soil stabilization is, however, still a novel process in the UK although it has been used in South Africa. This paper reports on efforts to extend the use of ggbs to highway and other foundation layers by determining the beneficial effect which it has on the reduction of expansion due to the presence of sulphates. The paper describes the results of laboratory tests on lime-stabilized kaolinite containing different levels of added sulphate to which different amounts of ggbs have been added. The tests determine the strength development of compacted cylinders, moist cured in a humid environment at 30°C, and the linear expansion of these moist cured cylinders on soaking in water. The results illus...
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Papers by zalihe nalbantoglu