Geotekstil, Geogrid ve Çelik Şerit Donatılı Şevlerde Modelleme Çalışması

Zeminin doğal koşullarının değişmesi, yüksek miktarda hafriyat gerektiren otoyol ve demiryolu kenarları veya destekli kazılardaki şev stabilitesi projelerinde beklenmedik gerilme artışlarına neden olmaktadır. Bu işlem sırasında farklı yükleme durumlarında bazı güvenlik sorunları oluşabilmektedir. Ek olarak, şev stabilitesi tasarımı ekonomik çözüm gerektirmektedir. Şev destek yapıları için bu önemli gereksinimler göz önünde bulundurularak en efektif tasarım yapılmalıdır. Bu çalışmada; kapsamlı bir literatür taramasının ardından, donatılı zemin yapısının ön kısmında yer alan derin kazılar dikkate alınarak şev stabilitesi problemi tüm yönleriyle incelenmiştir. Geotekstil (GT), geogrid (GG) ve çelik şerit (SS) donatılar, hem deney sürecinde hem de Plaxis yazılımı ile modelleme aşamasında şevin stabilite koşullarının arttırılması işleminde kullanılmıştır. Her donatı tipi zemin taşıma kapasitesi artışı sağlamış ve kendine has yer değiştirme davranışı göstermiştir. Dolayısıyla, sunulan değerlere göre taşıma kapasitesi ve yer değiştirme gereklilikleri doğrultusunda, tasarım işlemi ve sahadaki inşa sürecinde en efektif donatı elemanı seçilebilecektirChanging the natural conditions of soil creates unexpected stress increments in slope stability projects, which are required high amount of soil excavation near the highways and railways or braced cut systems. Some safety problems can occur during this application under different loading cases. In addition, slope stability design requires economical solutions. Slope-supporting structures should be designed with most effective solution according to these signified requirements. A slope stability problem considering deep excavations in front of the reinforced soils are studied within this study in all its parts, after an extensive review of the literature. Geotextile (GT), geogrid (GG) and steel strip (SS) reinforcements are used to increase the stability conditions of slope during both experimental procedure and modelling process with Plaxis software. Each reinforcement type provided the bearing capacity enhancement and showed that unique displacement behavior. Therefore, most effective reinforcement member can be chosen in design procedure and construction phase in the site according to the bearing capacity and displacement requirements according to presented value

Mechanics of a marine clay based on physico-chemical interactions with organic contaminants

Tez (Doktora) - Lehigh UniversityAnadolu Üniversitesi, Fen Bilimleri Enstitüsü, İnşaat Mühendisliği Anabilim DalıKayıt no: 18491The effects of municipal (sewage) sludge and crude oil on physi- cal and mechanical properties of laboratory prepared marine clays were investigated. Contaminants appeared to influence the development of clay microstructure and thus some of the physical and mechanical properties of sedimented marine clay. A mixture of illite, Ca-montmorillonite, kaolinite and chlorite minerals constituted the laboratory prepared ''marine clay''. The samples were prepared by allowing the marine clay slurry to settle in rectangular settling columns with sampling ports. Marine clay was premixed with the predetermined amount of contaminant and transformed into a slurry using saline water. The slurries were then poured into the settling columns, mixed in place and allowed to settle in a water column of 0.6 m of height. When the sedimentation was completed the water above the interface was drained through the sampling ports and undisturbed samples of the sediment were obtained by inserting a thin walled plastic tube into the sediment. Among the physical and mechanical properties measured or observed are physico-chemical properties, index properties, microst- ructure, shear strength, stiffness, permeability and compressibility. The influence of crude oil and sludge on these physical and mechani- cal properties and the microstructure was evaluated based on criteria such as flocculation, dispersion and Coulombic forces between the particles and the contaminants

Coupled flow of water in saturated kaolinite clay under multiple potentials

Tez (Doktora) - Lehigh UniversityAnadolu Üniversitesi, Fen Bilimleri Enstitüsü, İnşaat Mühendisliği Anabilim DalıKayıt no: 18999The purpose of this research was to test in the laboratory the validity of a phenomenological equation which combines linearly the forces causing flow of water in continuous clay systems. The equation is based on postulates of irreversible thermodynamics, the validity of which has not been established for clays subjected to combination of hydraulic, thermal and chemical potentials simultaneously. This provided the basis for the development of a new equipment with the objective of obtaining reliable data of water conduction through soil under these multiple potentials. A triaxial test system was developed to simultaneously apply constant hydraulic, thermal, and chemical potentials to a cylindrical soil specimen under confining pressure. The test system had five func- tional units, loading, heating, cooling, flexible wall permeability, and diffusion of chemicals. The various parts of the equipment can withstand large temperature differences (80 C) and chemical environ- ments with pH values ranging from as low as 1 to as high as 12. In addition to its conduction measurement capability, the system is also a conventional triaxial compression testing machine with computer aided data acquisition and real time display of load, displacement and pore pressures. The initial calibration tests showed good repeatabi- lity of data and thus stable functioning of the equipment. The potentials were initially applied separately, and then they were combined simultaneously with either flow allowed through the end boundaries of replicate kaolinite clay specimens. The experimental findings of cumulative flow of water under simultaneous application of the three gradients agreed well with the predictions made for cumulative flow using the superpositioning of the linear relations between the water flux and the forces. The agreement was observed despite the measured changes in the consistency and composition of the soil specimens under the particular magnitude and duration of the potentials applied. This validated the applicability of superpositio- ning to predict coupled flow with the applied hydraulic, osmotic, and thermal potentials. The superpositioning of the forces was not valida- ted when the coupled coefficients were determined from pore pressurmea surements at the potential application sites. In this case, superposi- tioning overestimated the flow since potential induced consolidatio

Design of A New Deep Soil Mixing System and Field Applications

Zemin iyileştirme; zemin özelliklerinin çeşitli yöntemler kullanılarak, istenilen düzeyde ıslah edilmesidir. Derin zemin karıştırma yöntemi (deep soil mixing) ise; çimento ve/veya diğer malzemeler ile zeminin yerinde karıştırılması işlemidir. Bu çalışmanın amacı; derin zemin karıştırma sistemi tasarımını detaylı olarak açıklayıp, örnek çalışmalar ile uygulama sonuçlarını literatüre sunmaktır. Çalışma sonucunda ülkemizde derin zemin karıştırma yönteminin bilinirliğinin ve uygulamalarının artması, tasarım aşamalarının açıklanması ile yeni ve farklı sistem tasarımları için yön verici ve cesaretlendirici olması umulmaktadır. Ayrıca, bu çalışma ülkemiz zemin iyileştirme piyasası ve uygulamacı mühendisler için yeni bir bakış açısı ve alternatif getirecektir.Soil improvement is the improvement of soil properties at required levels by using different types of methods. Deep soil mixing is the in-situ mixing of soil with using cement and/or other additives. The purpose this study is to explain the design of deep mixing system and also to give the results of the insitu studies to the literature. At the end of this study, it is expected that increase accustomed to using deep mixing and applications, due to explanations of the design steps to give encourage and collimating to new and different system designs. Besides, this study will give different points of view and alternative method for the engineer and contractors

The Effect of Basalt Fiber on the Performance of Stone Mastic Asphalt

Stone Mastic Asphalt (SMA) is a mixture design against rutting caused by intensive and heavy traffic loads. While modified bitumen needs to be used in this mixture, the use of cellulosic fibers is essential to prevent the infiltration of bitumen during the carriage of mixture due to high bitumen content. In this study, the effects of basalt fiber on the performance of SMA mixtures is investigated as an alternative to cellulosic fiber admixtures in the prevention of draindown. Raw materials commonly used in Turkey were chosen as Type-I graded limestone aggregate and B50/70 asphalt cement, according to the General Directorate of Highways. In total, 109 specimens were prepared by a gyratory compactor according to the superpave design method. Sixty of these specimens were basalt fiber added samples with a ratio from 0.1 % to 0.8 % by dry weight aggregate. An addition of basalt fiber of 0.6 % at 25 °C seriously increases the resilient modulus and tensile strength of the samples. In addition, 0.4 % basalt fiber mixed samples shows that the greatest resistance against permanent deformation according to the results of static uniaxial creep test performed at 40 °C. Basalt fibers have no positive effect when a decrement of bitumen viscosity exceeds the bitumen softening point at the end of repeated uniaxial tests. On the other hand, bitumen draindown and water damage test results are within acceptable limits

İki Tabakalı Zemin Profilinde Kazık Temellere Gelen Deprem Yüklerinin Eşdeğer Statik Yük Hesabı

Bu çalışmada, tabakalanmış suya doygun kil ve gevşek kum zeminlerde inşa edilen kazık gruplarına etki eden dinamik yüklerin statik yükler cinsinden uygulanabilirliği incelenmiştir. İki tabakalı zeminlerde oluşturulan kazık temellere üç farklı büyüklükte deprem yükü uygulanmış ve kazıkların yapmış oldukları deformasyonlar belirlenmiştir. Deprem etkisi altında kazık grubunun deformasyonlarının belirlenmesi için iki boyutlu Plaxis programının dinamik modülü kullanılmıştır. Analiz sonuçlarından geri hesap yöntemi ile kazık grubuna aynı deformasyonları yaptıracak eşdeğer statik yükler hesaplanmıştır

Investigation of electricity generation from multipurpose dams in Porsuk basın

Bu makalede, Porsuk Havzasındaki mevcut çok amaçlı barajların sahip olduğu küçük hidroelektrik enerji potansiyeli arastırılmıstır. Bu amaçla, çalısma alanı Porsuk Havzası seçilmistir. Porsuk Havzasındaki küçük ölçekli hidroelektrik potansiyelin değerlendirilmesi ve bölge/ülke ekonomisine kazandırılması amaçlanmıstır. Çalısmada esas olarak, elektrik üretimi amacıyla insa edilmeyen barajlardan bırakılan suyun (sulama, içme-kullanma ve endüstri suyu v.b) potansiyelini kullanarak, elektrik enerjisi üretilmesi konusu incelenmistir. Bu amaçla, mevcut barajlardan çıkan suların, aylar itibari ile 20 yıldan daha uzun yıllara dayanan verileri kullanılarak, bu barajlardan üretilecek elektrik enerjisi miktarı incelenmistir. Bu inceleme sonucunda, bu barajlardan 6,30 MW’lık kurulu bir güçle 30,113 GWh’lık elektrik üretilebileceği ve ekonomiye önemli bir katkı sağlayacağı görülmüstür.In this paper, small hydropower potential of existing multipurpose dams in Porsuk River basin has been investigated. For this purpose, Porsuk River basin has been selected as the research area. The aim is to evaluate the small hydropower potential in Porsuk River basin and to make it part of the region's/country's economy. This study basically investigates the subject of electricity generation through the use of water potential released from the dams which are constructed for supplying domestic, industrial and irrigation water but not for electricity generation. For this purpose, the amount of the electricity to be generated from these dams has been investigated by using the historical data of the discharge from these reservoirs to the downstream. Historical data of over 20 years has been analyzed on a monthly basis. It has been found that the electricity generation using this potential will be 30,113 GWh/year with 6,30 MW installed capacity. This potential will contribute an important monetary value to the economy

Hydrogen bonds between methanol and the light liquid olefins 1-pentene and 1-hexene: From novel application to fundamental science

We have recently developed a new extraction process for significantly reducing the olefin content in commercial FCC gasoline. To gain insights into the origins of this process , we have investigated the dissolution of the light liquid olefins 1-pentene and 1-hexene in methanol through computer modelling together with NMR spectroscopy. We find two important hydrogen bonding modes for methanol olefin interactions – namely, O-H···π and C-H···O

Investigation of the water potential of Porsuk basin with respect to hydroelectric energy production

Bu makalede, Porsuk havzasına ait küçük hidroelektrik enerji potansiyeli araştırılmıştır. Bu amaçla, çalışma alanı Porsuk havzası seçilmiştir. Porsuk havzasındaki küçük ölçekli hidroelektrik potansiyelin değerlendirilmesi ve bölge/ülke ekonomisine kazandırılması amaçlanmıştır. Araştırmada, Porsuk Çayı ve yan kolları üzerinde yeni planlaması yapılabilecek küçük hidroelektrik santrallerin yapılabilir olup olmadıkları araştırılmıştır. Makale’de, 1/25.000’lik haritalardan, baraj yerlerinin tespiti yapılmış, arazide bu yerlerin topoğrafik, zemin ve jeolojik bakımından uygunluğu incelenmiş ve uydu görüntüleri ile sayısallaştırılmış haritalarla desteklenmiştir. Bütün Porsuk havzası dikkate alındığında, Porsuk Çayı ve yan dereleri üzerinde planlaması öngörülebilecek 8 adet bölgede, yeni baraj yapımına uygun yerler tespit edilmiştir. Porsuk havzasındaki toplam su potansiyeli kullanılarak, 8,42 MW kurulu güç ile 30,212 GWh/yıl elektrik üretmek mümkündür. Bu yatırımların toplam maliyeti yaklaşık 75,65x106 US$olacaktır. Hesaplar, Porsuk havzasındaki su kaynaklarının ve yağışın, iklim değişikliği nedeniyle kuraklıktan$75.65x106. The affect of climate changes of Porsuk River is found in conditions when the water resources and rainfall are affected due to drought by 30%. The electrical energy amount received is greater in the case of normal levels of rainfall

Use of petroleum-contaminated drilling wastes as sub-base material for road construction

WOS: 000089656300010In this study, petroleum-contaminated drilling wastes were stabilized by mixing pozzolanic fly ash, lime and cement with them so they could be used as sub base materials for road construction. This stabilization produced physically, mechanically and chemically stabilized new mixtures. The laboratory study consisted of unconfined compressive strength, permeability, California bearing ratio, freeze/thaw (durability) and leachate on compacted stabilized samples, pH, electrical conductivity, cation exchange capacity and total metal contents on stabilized mixtures. Significant increases in the unconfined compressive strength, California bearing ratio, durability and pH were obtained by treating lime, fly ash and cement with petroleum drilling wastes. Significant decreases were obtained in electrical conductivity, cation exchange capacity, oil content and total metal concentrations both in mixtures and in leachate. The best result in all of the tests conducted was obtained with petroleum-contaminated soil stabilized with 20% lime, 10% fly ash and 5% cement. This mixture can be effectively and safely used as sub-base material