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The performance of energy geo-structures is also dependent on the surrounding soil properties in the presence of high temperatures or thermal cycles. Change in temperature may affect many engineering parameters of soils. Sand-bentonite mixtures or bentonite which are used as a buffer should keep their performance at design level for a long time. Purpose: In order to improve engineering behavior of soils under high temperatures thermally durable materials can be used. Volume deformation and hydraulic conductivity behavior of 30% bentonite-70% sand mixtures in the presence of fiberglass additives were investigated. Methods: Consolidation tests were performed at both room and high temperatures (80 °C), hydraulic conductivity tests were started at room temperature and temperature cycle (25-50-80°C) was applied. Results:Fiberglass increased the amount of compression insignificantly under room temperature, whereas the total compression amount increased remarkably under high temperature. On the other hand, the hydraulic conductivity increased under high temperature with fiberglass additive. Conclusions: Fiberglass added sand-bentonite mixtures can be used around energy structures as an alternative buffer material with high temperature resistance.

© The Authors, published by EDP Sciences, 2020.Depending on increase in the number and type of energy geostructures, studies on the change in soil behavior against heat increase becomes more important. The engineering properties such as permeability, volume deformation of surrounding soils around energy structures mustn't alter in the presence of heat and thermal cycles. Pumice is a material used in many fields especially for thermal insulation. For that reason, pumice can be used for increasing the resistance of soils in the presence of heat. In this study, the shear strength behavior of sand-bentonite mixtures was investigated with pumice additive under high temperature. In the experiments, 10% and 20% pumice were added to 10% and 20% sand-bentonite mixtures and compaction, direct shear tests were conducted. The direct shear tests were performed both room temperature and under 80°C. The results have shown that the pumice additive increased the shear strength of sand-bentonite mixtures under high temperature when compared the test results under room temperature.

The number of studies on the thermal behavior of soils have increased because of increase in number and type of energy structures in last decades. The soils around energy structures must retain without any changes at their engineering properties against temperature changes or thermal cycles. Pumice is used for increasing strength of materials against high temperature. It is expected that when the pumice is added to the soil, it may increases the strength of the sand-bentonite mixtures under high temperatures. For that reason, 10% and 20% pumice were added to sand-bentonite mixtures and compaction, consolidation behaviors at room temperature were investigated. In addition, the shear strength behavior of 10% bentonite-sand mixtures in the presence of 10% and 20% pumice additive under room temperature and 80C was investigated. According to the results of the consolidation tests, the total vertical strain increased as the pumice content in the mixture increased. According to the results of direct shear test, it was observed that pumice additive under room temperature and 80C increased the internal friction angle of 10% bentonite-sand mixtures. Especially under high temperature (80C), the internal friction angle of the sample increased when 20% pumice additive was added., Zeminlerin ısı varlığında davranışları üzerine yapılan çalışmalar, son yıllarda enerji yapılarının sayısı ve türündeki artış nedeniyle önem kazanmıştır. Enerji yapılarının etrafındaki zeminler, sıcaklık artışlarına karşı tasarım aşamasındaki mühendislik özelliklerini koruyabilmelidir. Pomza, endüstride malzemelerin termal etkilere karşı dayanımını artırmak için kullanılan bir malzemedir. Bu nedenle pomzanın kum-bentonit karışımlarına eklenmesi bu karışımların termal etkiler altında dayanımının artmasını sağlayabilir. Bu çalışmada bentonit-kum karışımlarına %10 ve %20 oranlarında pomza katkısı eklenmiş, kompaksiyon ve konsolidasyon davranışları incelenmiştir. Ayrıca %10 bentonit-kum karışımlarının oda sıcaklığı ve 80C altında %10 ve %20 pomza katkısı varlığında kayma davranışı incelenmiştir. Konsolidasyon deneylerinin sonuçlarına göre, karışımda pomza içeriği arttıkça toplam düşey deformasyonun arttığı görülmüştür. Yapılan direk kesme deney sonuçlarına göre oda sıcaklığı ve 80C altında pomza katkısının, %10 bentonit-kum karışımlarının içsel sürtünme açısını arttırdığı görülmüştür. Özellikle yüksek sıcaklık (80C) altında katkısız numunenin içsel sürtünme açısı, %20 pomza katkısı eklendiğinde artış göstermiştir.

Many methods are used to improve the engineering properties of the soils. While the some of the developed methods cannot produce an effective solution, some of them are not economical for practical solution. In this study, permeability and shear strength behaviors of natural kaolin, bentonite and sand mixtures have been investigated in the presence of three different biopolymers (xanthan gum, chitosan and chitin) and different concentrations (0.25-0.50-0.75 and 1%). The results have shown that, the xanthan gum and chitosan addition decreased the permeability coefficient almost 30 hold. While the biopolymer effect on shear strength behavior is investigated, 1% xanthan gum and chitosan concentration addition provided 15-10% increase in angle of internal friction. The obtained test results have shown that, biopolymers can be used in dams and landfills at impermeable clay liner applications.

© 2018, Springer Nature Switzerland AG.In this study, the settlement behavior of the embankment due to the surcharge loading have been visually and quantitatively investigated. The spatial variation of settlements of an oversized embankment have been monitored using aerial images taken at intervals. In order to achieve the deformations due to the surcharge loading in the field, two topographical three-dimensional models (before and after surcharge loading), derived from aerial images and ground control points, have been generated and compared. The aerial images were acquired by an unmanned aerial vehicle with autonomous flight capabilities. The topographies were compared by generating two cloud point models. The deformations, determined from the comparison of two cloud points, were visualized by assigning an intensity value, which was calculated based on the three-dimensional variations of each data point. The surficial settlement profiles nearby the surcharge load have been computed. It has been concluded that centimeter level accuracy on surficial settlement has been achieved by low altitude aerial images, although the illumination condition of the area has an influence on the measurements.

Gelişen dünya nüfusunaparalel olarak kentsel katı atık miktarı her geçen gün artmaktadır. Mühendisliközellikleri iyi tanımlanmamış katı atıklar ile yapılan kontrolsüz depolamalarsonucu oluşan göçmeler can güvenliğini tehlikeye atmakta ve büyük ekonomik kayıplaraneden olmaktadır. Bu çalışmada laboratuvar koşullarında belirlikompozisyonlarda sentetik olarak üretilmiş ve doğal atık depolama sahasındanalınmış taze ve yıllanmış kentsel katı atık (KKA) numunelerinin doğal suiçeriği, organik madde miktarı, özgül ağırlık ve pH değerleri belirlenmiştir.Doğal ve sentetik KKA numunelerinin kayma mukavemeti parametreleri büyükölçekli direk kesme cihazıyla belirlenmiştir. Elde edilen mühendislikparametreleri kullanılarak mevcut ve tasarlanmış KKA şevlerinin duraylılıkanalizleri yapılarak statik ve dinamik koşullar altında güvenlik sayılarıbelirlenmiştir. Çalışmadan elde edilen Türkiye KKA kompozisyonuna aitmühendislik parametreleri ve duraylılık analizleri sonuçları kullanılarak,Türkiye’de daha güvenli ve ekonomik KKA depolama sahalarının tasarımıyapılabilir., In parallel withthe developing world population, the amount of urban solid waste increases dayby day. Uncontrolled storage of solid wastes with poorlydefined engineering properties can result in a risk of life safety and seriouseconomic loss. In this study, natural water content, organic matter content,specific gravity and pH values of the synthetic waste (with pre-determinedcompositions) and natural waste samples were investigated in laboratoryconditions. Shear strength parameters of the synthetic and natural municipalsolid waste (MSW) samples were determined by using a large scale direct sheartest system. The slope stability analyses were conducted for present slopes atstatic and dynamic conditions and the factor of safety values were obtained.The obtained Turkey MSW composition engineering parameters can be used in thedesign of safe and economical MSW storage areas in Turkey.

Zeminlerin mühendislik özelliklerini iyileştirmek amacıyla birçok metot kullanılmaktadır. Geliştirilen metotların bazıları etkili bir çözüm üretemezken bazılarıysa pratik amaçlar için ekonomik olmayabilir. Bu çalışmada doğal kaolin, bentonit ve kum karışımlarının permeabilite ve kayma dayanımı davranışları üç farklı tür biyopolimerin (zantan gam, kitosan ve kitin) %0.25, %0.5, %0.75, %1 konsantrasyonları varlığında incelenmiştir. Deney sonuçları incelendiğinde zantan gam ve kitosanın permeabilite katsayısında 30 katı bulan azalmalara neden olduğu görülmüştür. Biyopolimerlerin kayma dayanımına etkisine bakıldığında %1'lik zantan gam ve kitosan konsantrasyonunun içsel sürtünme açısı değerinde %10-15 oranında bir artış sağladığı belirlenmiştir. Bu çalışmadan elde edilen sonuçlar biyopolimerlerin geçirimsiz kil bariyerlere ihtiyaç duyulan baraj gövdelerinde ve çöp depolama alanlarında kullanılabileceğini göstermiştir Many methods are used to improve the engineering properties of the soils. While the some of the developed methods cannot produce an effective solution, some of them are not economical for practical solution. In this study, permeability and shear strength behaviors of natural kaolin, bentonite and sand mixtures have been investigated in the presence of three different biopolymers (xanthan gum, chitosan and chitin) and different concentrations (0.25-0.50-0.75 and 1%). The results have shown that, the xanthan gum and chitosan addition decreased the permeability coefficient almost 30 hold. While the biopolymer effect on shear strength behavior is investigated, 1% xanthan gum and chitosan concentration addition provided 15-10% increase in angle of internal friction. The obtained test results have shown that, biopolymers can be used in dams and landfills at impermeable clay liner applications

Investigation of aging effect is important due to examination of long-term influence of contaminants on the landfill liners. The effect of Na + and Ca 2+ ions on the engineering behavior of soils were examined and the aging effect on engineering properties of kaolin and bentonite samples in the presence of ions were observed. The pore size distribution, swelling and shear strength parameters were determined under the same conditions after approximately 60, 190 (shear strength), and 250 (swelling) days. There is no difference at the swell index values of kaolin in the presence of DI water and 0.5 M NaCl. However, Ca 2+ ions decreased the swell index of the kaolin sample. In the presence of Na + ions, there is no difference at the swell index values of the bentonite sample. However, in the presence of Ca 2+ ions, swell index decreased from 0.035 to 0.029. During aging, the reverse effect occurs at bentonite sample when compared with kaolin sample. It is expected that, as aging progresses, bonds between particles increase; therefore, the swell index of the soils decrease. However, the results of this study have shown that this is not true for bentonitic samples. When the results of 0 day, 60 and 190 days samples were compared, the O' values of kaolin and bentonite samples decreased by time.