TR-Dizin İndeksli Yayınlar Koleksiyonu
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Article Tekrarlı Trafik Yükleri Altında Farklı Kil İçeriklerine Sahip Orta-Sıkı Kum-Kil Karışımlarının Esneklik Modülünün İncelenmesi(2021) Fedakar, Halil İbrahimEsneklik modülü, tekrarlı trafik yükleri altında yol temel tabakalarının uzun dönem deformasyon performansının tahmin edilmesinde yaygın olarak kullanılmaktadır. Bu nedenle, bu malzeme özelliğinin doğru tayini yol tasarımlarında büyük öneme sahiptir. Bu çalışmada, orta sıkı kum-kil karışımlarının esneklik modülü, dinamik üç eksenli ve kalp şekli gerilme izleri ile araştırılmıştır. Bu amaç doğrultusunda, ağırlıkça %0, %5, %10 ve %20 kil içeren kum-kil numuneleri %50 başlangıç rölatif sıkılıkta hazırlanmış ve yarık silindir deney cihazı kullanılarak test edilmiştir. Deney sonuçlarına göre kum-kil karışımlarının esneklik modülü değerleri dinamik üç eksenli gerilme izi ile daha fazla tahmin edilmektedir. Bu durum ise orta-sıkı kum-kil karışımlarının trafik yükleri altındaki deformasyon davranışının kalp şekli gerilme izine kıyasla daha düşük tahmin edilmesine sebep olmaktadır. Bu çalışmanın bulgularına dayanarak, kum-kil karışımlarının esneklik modülünün yol tasarımlarıiçin daha doğru bir şekilde tahmin edilmesinde kalp şekli gerilme iziningöz önüne alınması gerektiği sonucuna varılmıştır.Article Kalabak Tepe Kireçtaşlarının Nihai Taşıma Gücünün Farklı Analiz Yöntemleri ile Araştırılması(2024-04-30) Kıncal, Cem; Koken, Ekin; Koca, Tümay Kadakci; Kuruoglu, MehmetFarklı kütle özelliklerine sahip kayaç kütlelerinin taşıma gücünü en doğru şekilde tahmin eden yöntemlerin seçiminde karşılaştırmalı çalışmalar önem kazanmaktadır. Hangi yöntemin daha sağlam sonuçlar verdiği dayandıkları parametrelerle ilişkili olmaktadır. Bu çalışmada, Miyosen yaşlı Kalabak Tepe (İzmir) kireçtaşlarının taşıma gücü incelemesi değişik yöntemler uygulanarak gerçekleştirilmiştir. Kayaç kütle özellikleri Genelleştirilmiş Hoek-Brown yenilme ölçütü dikkate alınarak belirlenmiştir. Taşıma gücü için uygun yöntemlerin belirlenmesinde arazi modeli ve süreksizliklerin konumları dikkate alınmıştır. Kayacın kütle dayanım parametreleriyle birlikte limit analiz veya sonlu elemanlar yöntemlerinin taşıma gücü analizlerinde kullanılması uygun bir yaklaşım olmaktadır. Sonlu elemanlar yöntemiyle kireçtaşlarının nihai taşıma gücü, limit analiz yöntemlerinden elde edilenlerle karşılaştırılmıştır. Sonuç olarak, bazı limit analiz yöntemlerinden elde edilen sonuçlar, sonlu elemanlar ve diğer limit analiz yöntemlerinden elde edilenlerden daha yüksek bulunmuştur. Yöntemler arasındaki bulgu farklılıkları detaylıca tartışılarak yöntemlerin pratik kullanımına ışık tutulmuştur.Article Geological-Geochemical Signatures of Opal Occurrences in Keciborlu (Isparta-Turkey)(Pamukkale Univ, 2022) Baspinar Tuncay, Ebru; Koken, Ekin; Kuscu, Mustafa; Cengiz, Oya; Aydemir, Fatih; Raimov, Rahmen; Tuncay, Ebru BaspınarSilica-rich solutions, considered as the final products of acidic volcanism, which started from the Late Miocene to throughout the Plio-Quaternary around Isparta, are effective along the main fault observed around the Keciborlu (Isparta) sulfur deposit. Therefore, opal occurrences are intensively observed along this fault zone. Opal occurrences are in various colors such as gray, beige, yellowish, reddish, blackish. Opals with a massive structure, observed as bands, are sharp -edged, conchoidal diffraction, translucent, matte, oily glossy surface opals are iron oxidized. Some opals contain brecciated rock fragments. The locations of the opal occurrences in the field were determined in this study. Using representative samples, structural and textural properties of opals were determined by thin section, scanning electron microscopy analyses, and mineral paragenesis was analyzed via x-ray diffraction and Fourier transform infrared spectroscopy analyses. Geochemical findings revealed chemical compositions. Based on the thin-section studies, it was observed that the opalized samples lost their primary properties due to the effect of hydrothermal solutions and they became iron oxidized, laminated, and argillized. In addition, they contain opaque minerals such as magnetite and hematite. Different micro textures such as amorphous, granular, desert rose, and lepisphere quartz associations were observed in SEM images. In the XRD and FTIR analyzes, it was determined that most of the opals were Opal CT and some of them were defined as Opal C type. Based on the geochemical analyses considering Ba <120 ppm and Ca >200 ppm, the remarkable changes in loss on ignition values, and the relative relationship between C/T ratio and Ga, such hydrothermal alterations in opals the Keciborlu opals were found to have the magmatic origin.Article Citation - WoS: 1GIS-AHP Approach for a Comprehensive Framework to Determine the Suitable Regions for Geothermal Power Plants in Izmir, Turkiye(Konya Teknik Univ, 2024-02-15) Koca, Kemal; Karipoglu, Fatih; Ozturk, Emel ZerayGeothermal energy is gaining more reputation and importance around the world. Correspondingly, suitable location selection is a critical step and has become necessary for the successful installation and operation of geothermal power plants. This study investigated suitability of & Idot;zmir region, located in the Aegean part of T & uuml;rkiye, in terms of geothermal power plants applications by using the combination of Geographical Information System and Analytic Hierarchy Process. Based on the request of power plants, thirteen important criteria were evaluated under three main categories named as physical (C1), environmental (C2) and technical (C3). Moreover, expert's opinions were taken into consideration to calculate the importance of these criteria. Key results showed that & Idot;zmir was suitable for geothermal power plants. The final suitability map layer pointed out that %8.73 (1.037 km2) of total area were determined as highly suitable regions in terms of installation. In addition, the obtained suitability map layer was compared with actual geothermal power plants. Based on the comparison study, power plants in Seferihisar were moderately suitable for geothermal power plants while the location of Bal & ccedil;ova power plant was highly suitable. Regarding the suitability assessment in the present study, the location of Dikili power plants had the least suitability score.Article Citation - Scopus: 6A Comparative Study to Estimate the Mode I Fracture Toughness of Rocks Using Several Soft Computing Techniques(Murat Yakar, 2023-10-05) Köken, E.; Kadakci Koca, Tümay; Koca, Tümay KadakciFracture toughness is an important phenomenon to reveal the actual strength of fractured rock materials. It is, therefore, crucial to use the fracture toughness models principally for simulating the performance of fractured rock medium. In this study, the mode-I fracture toughness (KIC) was investigated using several soft computing techniques. For this purpose, an extensive literature survey was carried out to obtain a comprehensive database that includes simple and widely used mechanical rock parameters such as uniaxial compressive strength (UCS) and Brazilian tensile strength (BTS). Several soft computing techniques such as artificial neural network (ANN), adaptive neuro-fuzzy inference system (ANFIS), gene expression programming (GEP), and multivariate adaptive regression spline (MARS) were attempted to reveal the availability of these methods to estimate the KIC. Among these techniques, it was determined that ANN presents the best prediction capability. The correlation of determination value (R2) for the proposed ANN model is 0.90, showing its relative success. In this manner, the present study can be declared a case study, indicating the applicability of several soft computing techniques for the evaluation of KIC. However, the number of samples for different rock types should be increased to improve the established predictive models in future studies. © 2023 Elsevier B.V., All rights reserved.Article Modeling the Throughput of Horizontal Shaft Impact Crushers Using Regression Analyses, Artificial Neural Networks and Multivariate Adaptive Regression Spline(2022-10-27) Koken, EkinBu çalışmada, yatay milli darbeli kırıcıların (HSI) kırma kapasitesinin (Q), regresyon analizleri, yapay sinir ağları (ANN) ve çok değişkenli uyarlamalı regresyon analizi (MARS) kullanılarak araştırılmıştır. Bu amaçla, Türkiye'deki çeşitli taş ocaklarında ikincil kırma işlemlerinde kullanılan 32 farklı HSI tipi kırıcı ele alınmıştır. Çeşitli sayısal veriler (rotor genişliği (Rw), rotor çapı (Rd), rotor hızı (Vr), karakterize edilen besleme boyutu (d80), çalışma enerjisi (Oe) ve kırmataşın Los Angeles aşınma değeri (LAAV)) her bir kırma–eleme tesisinden elde edilmiştir. Öncelikle, toplanan veriler kullanılarak doğrusal ve doğrusal olmayan regresyon analizleri gerçekleştirilmiştir. Daha sonra ise, bu kırıcıların Q değerini tahmin etmek için farklı ANN ve MARS analizleri yapılmıştır. Sonuç olarak, kırıcıların Q değerini tahmin etmek için güçlü tahmin modelleri geliştirilmiştir. Önerilen modellerin (M6–M10) belirleme katsayısı (R2) 0.91 ile 0.98 arasında değişmekte olup, söz konusu yüksek R2 değerleri geliştirilen modellerin göreceli başarısını göstermektedir. Bu nedenle, önerilen modeller, araştırılan HSI tipi kırıcıların Q değerini tahmin etmek için güvenilir bir şekilde kullanılabilir. Bununla birlikte, HSI tipi kırıcıların Q değerini etkileyen diğer faktörleri araştırmak için örnek çalışmalarının sayısı arttırılmalıdır.Article Citation - Scopus: 10Kaya Tutma Hendek Performansının 3-Boyutlu Kaya Düşme Analizleriyle Değerlendirilmesi: Akköy (Ürgüp) Örneği(TMMOB - Jeoloji Muhendisleri Odasi jmo@jmo.org.tr, 2019-12-15) Akin, Mutluhan; Dinçer, İsmail; Orhan, Ahmet H.; Ok, Ali Özgün; Akin, Muge K.; Topal, TamerRockfall ditches or areas can be constructed in order to protect against rockfalls in settlements that are in danger of rockfalls when the population density is not high. Nevertheless, in the design of such protection structures, essential site-specific engineering studies and analyzes are often not carried out appropriately. Therefore, rockfallditches are occasionally not capable of preventing rockfalls. Within the scope of this study, the performance of a 2 m-deep and 1 km-long rockfall ditch excavated at the upper elevation of touristic Akköy (Ürgüp) settlement in 2012 in order to prevent the entrance of falling rocks to the residential area was evaluated on the basis of 3-dimensional rockfall analyses. According to the rockfall risk classification, the settlement is under moderate rockfall risk. The digital surface model used in 3-dimensional rockfall analyses was generated by point cloud data obtained from photogrammetric images taken by unmanned aerial vehicle. During field observations, it was determined that the dimension of the previously fallen ignimbrite blocks could reach up to 2 m. On the other hand, the high persistency of discontinuities in the source zone indicates that the dimensions of the potential rockfall blocks may be large. As a result of the 3-dimensional rockfall analyses carried out in RocPro3D software, it was defined that the falling blocks are generally caught by the ditch excavated between the source zone and the settlement, but in some sections of the ditch those blocks may continue to roll over the rockfall ditch. Eventually, Akköy settlement is still partially under the danger of rockfalls. If the rockfall ditch is not periodically cleaned in the course of time, the extent of danger will enlarge with the decrease in the capacity of the trench. © 2020 Elsevier B.V., All rights reserved.Article Citation - Scopus: 1Düzce Kent Merkezi Zeminlerinin Sıvılaşma Potansiyelinin Değerlendirilmesi(TMMOB - Jeoloji Muhendisleri Odasi jmo@jmo.org.tr, 2019-06-15) Akin, Muge K.Soil liquefaction is one of the ground deformations occurred during an earthquake which may cause serious damages such as settlement and tilting of structures due to loss of bearing capacity of foundations. Düzce and its surrounding settle on a plain which consists of silty and sandy layers with shallow groundwater level. Besides, the North Anatolian Fault Zone is a major seismic source which is capable of producing large magnitude earthquakes. All these data point out that the ground deformations like liquefaction and lateral spreading may occur during a probable large earthquake around Düzce and its close vicinity. In this study, the geotechnical data of 40 boreholes drilled to determine the local ground conditions and the groundwater level in Düzce were considered. Based on the field studies, it was aimed to evaluate the liquefaction potential considering the fact that the groundwater level is shallow as well as the subsurface soil is composed of loose alluvium. Liquefaction Potential Index (LPI) and Liquefaction Severity Index (LSI) methods were taken into account and the liquefaction potential of Düzce province was determined and mapped with respect to various earthquake scenarios in GIS environment. These maps are compared on the basis of different scenarios. Accordingly, it is concluded that the liquefaction potential is high-very high in the south and south-eastern sections of the study area where the construction of new residential buildings progressively continues. © 2019 Elsevier B.V., All rights reserved.Article Türkiye’de Farklı Yörelerde Bulunan Kolemanit Minerallerinin Fiziksel, Kimyasal Ve Termal Özelliklerinin Tayini(Gumushane University, 2021-08-24) Senol-Arslan, Dilek; Arslan, Dilek Senol; Şenol Arslan, DilekIn this study, colemanite is an important boron mineral which constitutes about 76% of Turkey's boron reserves, is frequently used in applications obtained as a result of scientific and technological developments. In this context, a detailed literature survey was carried out colemanite minerals. Characteristic and structural features of the colemanite samples of four different regions (Kestelek, Emet (Hisarcık, Espey), Bigadiç regions) were determined by analyzes such as X-Ray Diffraction (XRD), Inductively Coupled Plasma, ICP and Mass Spectrometry, MS (ICP-MS), Thermogravimetric and Differential thermal analysis (TG-DTA), and Fouier Transform Infrared Spectroscopy (FT-IR) methods. In line with these findings, the mineralogical, chemical and thermal properties of pure colemanite crystals were determined and the similarities and differences between the samples were revealed. © 2025 Elsevier B.V., All rights reserved.