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The current research focuses on nanoparticles’ ground-improvement potential using clayey soil mixed with varying amounts of the nanoparticles “Silicon Carbide”. With an increase in the amount of nanomaterial, a tendency of improvement has been recorded in liquid and plastic limits, as well as the plasticity index. The maximum reduction in liquid limit (15.8%), plastic limit (13.6%), and plastic index (18.7%) was recorded at 0.25 gm of Silicon Carbide as compared to control (0 gm of SiC). There was a 26.7% and 33.3% increase in the cohesion of soil at 0.25 gm and 0.3 gm of Silicon Carbide, respectively. Furthermore, when the Silicon Carbide content increased from 0.25 gm, the rate of increment of friction angle also increased. It was 87.5% and 137.5% at 0.25 gm and 0.3 gm of Silicon Carbide, respectively. Furthermore, 0.3 gm of Silicon Carbide, is found to be optimal within the scope of the experiment as at this amount of Silicon Carbide both cohesion and angle of friction attained maximum. XRD, SEM, and FTIR were used to confirm the findings. It concludes that by using even a small amount of nanomaterial, an appreciable change in the properties of clayey soil can be obtained in the field. First published online 16 December 2022

When moisture levels fluctuate, expansive soils lose a large amount of volume. During the rainy and dry seasons, this type of soil expands and contracts, respectively. As a result, such problematic soils should be avoided or appropriately managed when encountered as subgrade materials. The strength of the subgrade is measured in terms of its California Bearing Ratio (CBR) value which is tiresome, uneconomical, and time-consuming to determine in the laboratory. In the present study, the effect of bagasse ash (BA) and calcined termite clay powder (CTCP) on the strength, index, and microstructural properties of expansive soil was investigated. Laboratory tests such as Atterberg’s limits, particle size analysis, moisture-density relationship, and CBR tests were performed on the highly expansive soil and blended with 3%, 5%, 7%, 9%, and 11% bagasse ash (BA), and 5%, 10%, 15%, 20%, and 25% CTCP separately and in combination. In addition, the microstructural properties of the raw highly expansive soil and the soil stabilized with the optimum BA-CTCP combination were analyzed using the Scanning Electron Microscopy (SEM) machine. Soaked CBR prediction models were also developed using multiple linear regression (MLR) and artificial neural networks (ANNs) from the BA fraction (BAF), CTCP fraction (CTCPF), liquid limit (LL), plasticity index (PI), optimum moisture content (OMC), and maximum dry density (MDD). The soil understudy was very weak having a CBR value of 2.2% and a group index (GI) of 64.37 (reported as 20) and highly expansive with a PI of 51.61% and LL of 104.32%. The addition of both BA and CTCP separately and in combination had resulted in the reduction of PI and increased the strength of the soil under study. As compared with the individual effect, the combined effect of BA and CTCP was quite significant. The optimum BA and CTCP combination was determined from the free-swell index test result; a 72.5% reduction was observed when it was blended with a combination of 9% BA and 20% CTCP. Thus, 9% BA and 20% CTCP compositions could be the optimum percentage combination to stabilize the highly expansive soil under study. The PI was decreased by 85.75%, and the CBR became 5.5 times greater when it was stabilized with 11% BA + 25% CTCP. The SEM micrographs showed that the morphology and fabric of the control specimen (raw soil) were significantly changed when the soil was stabilized with the optimum BA-CTCP combination (9% BA + 20% CTCP). The MLR prediction model was shown to be less efficient and accurate than the ANN model.

Soil contamination is a global concern that has great effects on human health, groundwater, and the engineering properties of soil. The aim of this paper is to use the electrokinetic remediation technique to remove lead contaminants from lateritic soil and evaluate the index properties of the remediated soil. Contaminated soil specimens were prepared by mixing the lateritic soil with a maximum 1% lead nitrate concentration in a stepwise increment of 0.2% by weight of dry soil. Thereafter, the soil was remediated in an electrokinetic cell using graphite electrodes with acetic acid and ethylenediaminetetraacetic acid (EDTA) as electrolytes. The results obtained shows a liquid limit and the plasticity index of electrokinetic lead remediated soil decreased from 52.00 to 39.60% and 29.09 to 17.59%, respectively. The cation exchange capacity (CEC) of the electrokinetic lead remediated soil increased from 5.31 to 8.20 Cmolkg-1 after the electrokinetic process, while the liner shrinkage decreased from 12.14 to 5.0 %. The percentage passing the BS NO 200 sieve ranges from 7.68 to 5.85 for British Standard Light (BSL), 5.09 to 5.50 for West African Standard (WAS), and 10.4 to 5.60 for British Standard Heavy (BSH). Furthermore, the percentage of gravel for BSLranges from 1.6 to 14 for BSL, 1.6 to 13.4 for WAS, and 1.7 to 3.5 for BSH. Overall, the electrokinetic technique proved to be effective in removing lead from contaminated lateritic soil and improving its index properties. Results obtained provide valuable insight into the remediation of contaminated soil using the electrokinetic technique.

Представлены результаты предварительного исследования, проведенного для определения влияния небольшого количества хлорида калия (KCl) на эффективность мелкого шлака, используемого для обработки обширных почв. Количество KCl варьировалось от 0,5 до 1,5 %, в то время как количество мелкого шлака варьировалось от 5 до 15 % от веса почвы. Установлено, что пластичность и дифференциальное свободное набухание почвы снижается при добавлении KCl, а также мелкого шлака. KCl более компетентен в снижении пластичности и набухания почвы по сравнению с мелким шлаком. Увеличение прочности и максимальной сухой плотности относительно велико в случае с мелким шлаком по сравнению с KCl, добавленным в почву. Эффективность мелкозернистого шлака для изменения свойств обширного грунта значительно возрастает в присутствии небольшого количества KCl. Прогнозные модели также разрабатываются, чтобы выяснить улучшенные свойства обширной почвы. The article presents the results of a preliminary investigation carried out to determine the effect of a small amount of potassium chloride (KCl) on the efficiency of fine slag used for treatment of expansive soil. The quantity of KCl has been varied from 0,5 to 1,5 %, while fine slag was varied from 5 to 15 % of the soil weight. It is found that the plasticity and differential free swell of the soil reduces with the addition of KCl as well as fine slag. KCl is more competent in reducing the plasticity and swelling of soil compared to fine slag. Whereas, the enhancement in strength and maximum dry density is relatively large in case of fine slag as compared to KCl added to the soil. The efficiency of fine slag to alter the properties of expansive soil increases significantly in the presence of a small quantity of KCl. The predictive models were also developed to find out the improved properties of expansive soil.

Significant research investigations on the characteristics of unexplored clay deposits are being conducted in light of the growing need for clay in the ceramic industry and the variable chemistry of clays. Parallel to this, the generation of waste materials like fly ash, ferrochrome slag, and silica fume is also increasing, responsible for environmental degradation. This paper aims to study the mineralogical properties of pure clays (one specimen from Siberia and five specimens from different locations in Turkey), and the effect of mentioned waste materials on the index properties of clays obtained. This study is divided into two phases, wherein in the first phase, the pure clay specimens are analyzed against mineralogical properties (i.e., chemical composition, thermal analysis, and particle size distribution). While in the second phase, index properties of pure clay specimens and clay specimens modified with 0–50% fly ash, ferrochrome slag, and silica fume are analyzed. The results reveal that the clay specimens from Turkey (USCS classification: CL) are fit for the ceramic industry and bricks production, and incorporation of waste materials can further improve their index properties. It is also observed that incorporation of 10–30% fly ash and ferrochrome slag have higher efficiency in reducing the plasticity index of clays studied as compared to the addition of silica fume.

Expansive soil swells when it is wet, and it will shrink when it dries. Due to this behavior of the soil, the strength and other properties of soil are inferior. To improve its properties, it is necessary to stabilize the soil with different stabilizers. Soil stabilization is a process to treat the soil to maintain, alter, or improve expansive soil performance. In this study, the potential of 'Fino' as stabilizing additive to expansive soil was investigated for the improving engineering properties of expansive soil to be used as subgrade material. The evaluation involved the determination of the Free Swell test, CBR test, Atterberg's limits, and the Proctor test of expansive soil in its natural state as well as when mixed with varying proportions of 'Fino.' The practices were performed on six proportions 5%, 10%, 15%, 20%, 25% and 30 % with expansive soil. The research result indicated a considerable reduction in Swelling, and the Maximum dry Density of soil was improved. Optimum moisture content decreased in increasing 'Fino.' At 30% of 'Fino,' the CBR values of expansive soil increased from 1.06% to 5.94%, Liquid Limit decreased from 95.2% to 29.4%, plasticity index decreased from 57.24% to 17.82% and the degree of expansion of the natural subgrade soil has reduced from "very high to medium." Hence, it is concluded that the 'Fino' at 30% has shown significant improvement in the expansive soil's engineering properties meeting the ERA and AASHTO Standard specifications requirements for road subgrade material.

Shear strength is the essential engineering property of soil required to analyze and design foundations, retaining walls, bridges, embankment, and related infrastructure. The laboratory equipment and field instruments are not sufficient in developing countries to obtain soil engineering properties, especially strength properties. Thus, Geotechnical engineers usually endeavor to develop statistical models that best fit a particular area and soil type, especially for analysis and design purposes. In this research, a Statistical Analysis on the Shear Strength parameter from the Index Properties of Fine-Grained Soils was studied. For predicting the undrained shear strength parameter, single linear regression (SLR) and multiple linear regressions (MLR) analyses were developed. To develop the intended statistical models for a study, SAS JMP Pro 13, SPSS v22, and Microsoft Excel-2013 software were introduced. The results of a study indicated that undrained shear strength(Cu) was significantly correlated with liquid limit(LL), plastic limit(PL), bulk density (ρbulk), dry density(ρdry), natural moisture content(NMC), and plasticity index(PI). While it was not significantly correlated with a specific gravity (Gs) and liquidity index (LI) of study area soil. Finally, a strong Model of Cu with a coefficient of determination (R2 = 0.806), good significance level, and less Std. error was obtained from multiple linear regression (MLR) analysis. The developed model can figure undrained shear strength parameter and wide application in the construction industry to minimize the cost, effort, and time for laboratory tests of shear strength parameter of a study area.

The expansive soil obtained from Baure in Yamaltu Deba Local Government Area was rich in clay mineral (montmorillonite), unstable and difficult to use for construction purposes. The soil treated with up to 12% palm kernel shell ash (PKSA an agro – waste) by weight of dry soil to improve index properties and compaction characteristics of the soil using PKSA. Index tests were carried out to classify the natural soil, while the moisture-density relationships were determined by compaction tests on the natural and treated soils using three energy levels viz, British Standard light (BSL), West African Standard (WAS) and British Standard heavy (BSH). BCS used in the study was classified as A-7-5 (20) using the American Association of State Highway and Transportation Officials (AASHTO) and CH group in the Unified Soil Classification System (USCS). Tests results show that specific gravity of the soil increased from 2.29 for the natural to 2.34 at 12% treatment. Liquid limit decreased from 76.2% for natural to 73.4% at 10% PKSA content. Plastic limit increased from 40% for the natural soil to 47.1% at 12% PKSA content treatment. Maximum dry density (MDD) values decreased from 1.44Mg/m3, 1.5Mg/m3 and 1.65Mg/m3 for the natural soil to 1.38Mg/m3 at 10%, 1.45Mg/m3 at 10% and 1.56Mg/m3 at 6% PKSA content for BSL, WAS and BSH compaction energy levels respectively. On the other hand, optimum moisture content (OMC) value decreased from 28.5% and 22.4% for the natural soil to 22.4% and 21.0% at 12% PKSA content for BSL and WAS energies respectively while the value for BSH energy increased from 18.2% to 19.0% at 8% PKSA content. Results show that PKSA is suitable for the improvement of the index properties and compaction characteristics of BCS; and its beneficial use will reduce the attendant disposal problem on the environment.

The quality of designed structures embedded in rocks is strongly related to rock strength parameters of intact rock. Measuring different parameters from tests could be very expensive in designing phase of projects. Estimating some parameters from other ones can reduce costs and time of project procedure. In this paper, the relationships between static and dynamic parameters of marls are studied by using the single and multiple linear regressions. For this purpose, several marl core samples from Seydoon region, Khoozestan Province in Iran are collected and tested. Some equations with sufficient correlation have been obtained to predict the engineering parameters of marls, especially the uniaxial compressive strength (UCS).

This research addresses a rockslope on the motorway No. 228, labeled as a 2A category road, according to the official road authority—Public Enterprise Roads of Serbia, which links Prolom Banja with a higher-category road network. Prolom Banja is an uprising touristic destination, famous for its spa and wellness resort, which shows an increasing trend of visits (over 10k tourists per month in the peak-season). As the road 228 is the only link to the resort, there is a raising concern about the road safety for about 650 vehicles per day (on average) along its many critical road cuts. One such rockslope (Lat 43.039850, Lon 21.380114) in weathered, jointed andesite is exampled in this research, using both terrestrial and airborne systems for reconstructing surface point-clouds, as well as the abovementioned index field and lab tests. These allowed quantifications of the rock joint sets and their kinematic stability, joint spacing, blocks volumes, and finally, profiling the critical blocks for potential rockfall development. It is planned to annually monitor the pilot site in the future, so that all changes, i.e. detached blocks and fragments will be identified.

WOS: 000334913500011, For the countries with a developed stone industry the waste generated in the natural stone processing plants pose environmental and economic problems. The utilisation of stone waste in various areas is still under research. In addition, there are only a limited number of studies concerning the use of stone waste obtained from processing plants in the stabilisation of clayey soil. Furthermore, none of the studies in the literature investigated the effect of the characteristics of the stone on the stabilisation of the soil. This is the first study that compares the efficiency of the waste calcitic marble, dolomitic marble and granite powder as additives for the stabilisation of clayey soil. Artificial soil samples were prepared in the laboratory using bentonite and kaolinite. Natural stone waste powder was added to the soil samples at different percentages, and the index and compaction parameters of the stabilised soil were analysed. The results showed that the types of waste powder used in this study, like lime, could be used as stabilisers. As the percentage of additives increased, the plasticity index of the clayey soil decreased and the physical properties of the soil changed from clay to silt. In terms of compaction parameters, the use of all types of natural waste powder in the study resulted in a decrease in the optimum water content and an increase in the maximum dry unit weight. The lowest optimum water content and the highest maximum dry unit weight were obtained from the dolomitic marble powder., Nigde University Scientific Research Projects Unit; Nigde University [FEB 2010/33], This study is supported by Nigde University Scientific Research Projects Unit. This paper is partly benefited from the FEB 2010/33 project of Nigde University. The authors would like to thank Nigde University Scientific Research Projects Unit and the Nigde NIDAS Company for allowing them to use the laser diffraction device.

The Schmidt hammer test is a non-destructive method which can be used in both laboratory and field to provide a quick and relatively inexpensive measure of rock hardness. The study investigated the relationship between the Schmidt hardness and modulus of elasticity, uniaxial compressive strength and index properties of nine types of rock including travertine, limestone, dolomitic limestone and schist. The empirical equations developed indicated the Schmidt hardness rebound values have a reliable relationship with the uniaxial compressive strength of rock (r = 0.92). Comparing the results with those reported by other researchers, it is concluded that no single relationship can be considered reliable for all rock types. Whilst the equations developed in this study may be useful at a preliminary stage of design, they should be used with caution and only for the specified rock types. © Springer-Verlag 2008.

La caracterización de las propiedades índices de los geomateriales es una de las labores más importantes en la ingeniería geotécnica, al ser estos un insumo fundamental para la identificación y determinación de propiedades geomecánicas de los suelos. Las principales propiedades índices estudiadas en la geotecnia son el contenido de agua, los límites de Atterberg, la granulometría, el peso unitario y la gravedad específica, las cuales son la base para clasificación de suelos. En este artículo se presenta el análisis estadístico de las propiedades índices de suelos tipo flujo de lodos de la ladera oriental de Medellín, a partir del análisis de 10 proyectos de acceso público y con información suficiente para los análisis, los cuales cubren un área aproximada de 3 km2. Los resultados evidencian bajos coeficientes de variación de las propiedades índices de los flujos de lodos, especialmente para la densidad húmeda y granulometría, porcentajes de saturación altos y, según los límites de Atterberg, estos suelos se encuentran primordialmente en estado plástico.

Stability with first time or reactivated landslides depends upon the residual shear strength of soil. This paper describes prediction of the residual strength of soil based on index properties using two machine learning techniques. Different Artificial Neural Network (ANN) models and Support Vector Machine (SVM) techniques have been used. SVM aims at minimizing a bound on the generalization error of a model rather than at minimizing the error on the training data only. The ANN models along with their generalizations capabilities are presented here for comparisons. This study also highlights the capability of SVM model over ANN models for the prediction of the residual strength of soil. Based on different statistical parameters, the SVM model is found to be better than the developed ANN models. A model equation has been developed for prediction of the residual strength based on the SVM for practicing geotechnical engineers. Sensitivity analyses have been also performed to investigate the effects of different index properties on the residual strength of soil.

In this review article, various antenna designs that are based on metamaterial concepts are presented which have been developed at the University of Toronto. Specifically, several antennas that are based on the zero-index property of transmission-line metamaterials are reviewed, and it is demonstrated that compact, multiband and highly efficient antenna designs can be achieved. Additionally, two other antenna designs that use electric-LC (ELC) field coupled resonator and complimentary-split-ring-resonator (CSRR) metamaterial "particles" are also reviewed, and it is demonstrated that these designs can also offer multiband and/or wideband performances. Through this work, and even though some of the antenna designs utilize only a single metamaterial unit cell, it is demonstrated that the metamaterial conceptual route can lead to innovative antenna designs with excellent performance characteristics.

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2007, Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2007, Zeminler yüklemeye maruz kaldıklarında sıkışma davranışı sergilerler. Sıkışma, zemin danelerinin yer değiştirmesi ya da deformasyonu ve boşluk suyunun uzaklaşması ile oluşur. Zeminde boşluk suyu basıncının zamana bağlı sönümlenmesi konsolidasyon oturmasını ifade etmektedir. Zeminlere ait oturma davranışı konsolidasyon ya da ödometre deneyi olarak bilinen laboratuar deneyi ile saptanmaktadır. Deneyde zamana bağlı sıkışmalar, her yük kademesinde en az 24 saat süren yüklemeler sonucunda belirlenmektedir. Bu nedenle konsolidasyon deneyinin sonuçlanması uzun zaman almaktadır.Bu çalışmada, zemin indeks özelliklerinin zemin oturma davranışına olan etkileri incelenmiş, bu özelliklerinin oturma davranışını açıklamakta yeterli olup olmadığı araştırılmıştır. 299 adet örselenmemiş zemin numunesi üzerinde yapılan konsolidasyon deneylerine ait indeks özellikleri istatistiksel yöntemlerle incelenmiş; sıkışma indisi, kabarma indisi ve hacimsel sıkışma katsayısı parametrelerinin indeks özellikleri ile olan korelasyonları bağıntılar halinde sunulmuştur.Çalışmada istatistiksel yöntemlerden değişken eleme yöntemli regresyon analizi uygulanmıştır. Boşluk oranı, tabii su muhtevası, plastisite özellikleri ve birim hacim ağırlığı gibi indeks özellikleri analize dahil edilmiş, analiz sonucunda etkisi olmayan parametreler adım adım işlemden çıkarılarak analizler takrarlanmıştır. Tüm modellere ait belirlilik katsayıları belirlenerek, elde edilen korelasyonlar denklemler halinde sunulmuştur., When soils subjected to loading they tend to show compression behavior. Compression occurs by relocation or deformation of soil particles or expulsion of pore water.Consolidation settlement could be expressed by the expulsion of pore water.Compression behavior of soils is determined by laboratory experiment named consolidation or odometer test. Soil specimen is loaded for at least 24 hours for the determination of compression by time for all loading levels. For this reason, consolidation test takes long time.In this study the effect of index properties on compression behavior of soils is investigated. The relationship between consolidation parameters and index properties of soils are studied and defining statistical correlations is aimed. Consolidation tests which are carried on 299 undisturbed soil samples are investigated with statistical procedures and correlations are established between the compression index, swell index and coefficient of volume compressibility with index properties. Backward selection regression analysis procedure is applied for the study. The parameters such as void ratio, plasticity parameters and unit weight are joined to the analysis, then the ineffective parameters are separated from the model. Gathered information is established with linear equations with coefficient of significances., Yüksek Lisans, M.Sc.