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Öğe DYNAMIC BEHAVIOUR OF HISTORICAL BAYBURT GRAND MOSQUE(Yildiz Technical Univ, 2020) Yurdakul, Muhammet; Yilmaz, Fatih; Artar, MusaIn this study, the locations of the damages that would occur when a historical building was exposed to different earthquakes were determined. The selected building is Bayburt Ulu Mosque located in the city center of Bayburt and it was built by the Anatolian Seljuk Sultan II. Giyaseddin. This selected historical building is modelled according to the macro modelling technique in the SAP2000 program using the finite element method. Modules of elasticity, poisson's ratio and weight per unit of volume of Bayburt Stone which is used in the mosque are determined by the experiment. Also, the properties of the ground on which the building was built are determined. As earthquake records which recorded on similar grounds, components of DZC180 and DZC270 of 17 August 1999 Kocaeli earthquake, components BOL000 and BOL090 of 12 November 1999 Duzce earthquake and components of ERZE-EW and ERZE-NS of 13 March 1999 Erzincan earthquake are used. In the results of the dynamic analysis made, quantities and locations of the strains that can occur in the historic mosque are determined.Öğe Effect of fineness on lime stabilization of low plasticity clays(Parlar Scientific Publications, 2020) Yilmaz, Fatih; Kocabey, SefaIn this study, stabilization with lime was investigated within the scope of surface soil stabilization. The main aim of the study is to examine the grindability of the lime and investigate the effect of grinded lime on the strength and durability behavior of stabilized soil. This paper is divided into two parts. The first part deals with the grindability of the lime. The second part analyses the results of geotechnical tests with grinded and ungrinded lime. Ungrinded lime, 90% of which is below 48 microns, was reduced to less than 20 microns. The test samples were prepared by adding 2%, 4%, 6%, 8% and 10% of grinded and ungrinded lime to a low plasticity clay according to the Unified Soil Classification System. Curing times for strength tests were determined as 1, 7, 14 and 28 days. The properties of the prepared mixtures were investigated by their geotechnical properties such as index, strength and durability. In the light of the data obtained from the experiments, it is concluded that the fineness of the lime has a direct positive effect on the strength and durability characteristics. © 2020 Parlar Scientific Publications. All rights reserved.Öğe EFFECT OF FINENESS ON LIME STABILIZATION OF LOW PLASTICITY CLAYS(Parlar Scientific Publications (P S P), 2020) Yilmaz, Fatih; Kocabey, SefaIn this study, stabilization with lime was investigated within the scope of surface soil stabilization. The main aim of the study is to examine the grindability of the lime and investigate the effect of grinded lime on the strength and durability behavior of stabilized soil. This paper is divided into two parts. The first part deals with the grindability of the lime. The second part analyses the results of geotechnical tests with grinded and ungrinded lime. Ungrinded lime, 90% of which is below 48 microns, was reduced to less than 20 microns. The test samples were prepared by adding 2%, 4%, 6%, 8% and 10% of grinded and ungrinded lime to a low plasticity clay according to the Unified Soil Classification System. Curing times for strength tests were determined as 1, 7, 14 and 28 days. The properties of the prepared mixtures were investigated by their geotechnical properties such as index, strength and durability. In the light of the data obtained from the experiments, it is concluded that the fineness of the lime has a direct positive effect on the strength and durability characteristics.Öğe Investigation of time-history response of a historical masonry minaret under seismic loads(Elsevier Science Inc, 2021) Yurdakul, Muhammet; Yilmaz, Fatih; Artar, Musa; Can, Omer; Oner, Erdal; Daloglu, Ayse T.This study presents an investigation of the seismic performance of a historical masonry minaret which was built in the 12th century in Bayburt. The minaret was built as masonry with regional stones and handmade bricks. The most important feature of the minaret is its longitudinally conical geometry. An experimental investigation was made to obtain the mechanical properties of the regional stone used in the historical minaret. A three-dimensional Finite Element Model of the historical minaret was created in SAP2000. Three earthquake ground motions such as Erzincan, Kocaeli-Duzce, and Van-Ercis were used to investigate the seismic performance of the historical minaret. The results show that Erzincan, Kocaeli-Duzce and Van-Ercis earthquakes may cause some damages in the same zone of the minaret body since the tensile stresses occurred due to the earthquakes exceed the limit tensile stress of the masonry brick. The use of the data obtained from the experimental investigation of the Bayburt yellow stone in the analysis is important for the reliability of the results.Öğe Investigation on seismic isolation retrofit of a historical masonry structure(Techno-Press, 2019) Artar, Musa; Coban, Keziban; Yurdakul, Muhammet; Can, Omer; Yilmaz, Fatih; Yildiz, Mehmet B.In this study, seismic vulnerability assessment and seismic isolation retrofit of Bayburt Yakutiye Mosque is investigated. Bayburt Yakutiye Mosque was built in the early 19th century at about 30-meter distance to Coruh river in the center of Bayburt in Turkey. The walls of historical masonry structure were built with regional white and yellow stones and the domes of the mosque was built with masonry bricks. This study is completed in four basic phases. In first phase, experimental determination of the regional white stone used in the historical structure are investigated to determine mechanical properties as modulus of elasticity, poison ratio and compression strengths etc. The required information of the other materials such as masonry brick and the regional yellow stone are obtained from literature studies. In the second phase, three dimensional finite element model (FEM) of the historical masonry structure is prepared with 4738 shell elements and 24789 solid elements in SAP2000 software. In third phase, the vulnerability assessment of the historical mosque is researched under seismic loading such as Erzincan (13 March 1992), Kocaeli (17 August 1999) and Van (23 November 2011) earthquakes. In this phase, the locations where damage can occur are determined. In the final phase, rubber base isolators for seismic isolation retrofit is used in the macro model of historical masonry mosque to prevent the damage risk. The results of all analyses are comparatively evaluated in details and presented in tables and graphs. The results show that the application of rubber base isolators can prevent to occur the destructive effect of earthquakes.Öğe Optimization, Characterization, and Carbon Footprint Analysis of Alkali Activated Waste Tuff and Fly Ash Mixtures for Deep Mixed Columns(Springer Science and Business Media Deutschland GmbH, 2024) Kamiloğlu, Hakan Alper; Yilmaz, FatihDeep soil mixing (DSM) applications are one of the widely known soil stabilization techniques which can be applied to a wide range of soil types. Cement and lime are the major materials used as binders for DSM applications. However, as conventional binders lead to emit a large amount of CO2 during production, eco-friendly binders suitable for DSM applications have become prominent. Alkali-activated materials are good alternatives to conventional binders. This study was intended to investigate the usability of zeolite rich tuff wastes as an alkali-activated binder in DSM columns. Within this scope, the waste tuff and C-type fly ash mixture were used as an alkali-activated binder, and 10 M NaOH solution was used as an activator. Response surface methodology (RSM) was employed in experimental design to determine optimum components to obtain maximum unconfined compression strength and investigate the interaction between stabilization agents. From the RSM analysis the optimum ratios of activator (X1), waste tuff (X2), and precursor (X3) were determined as; X1 = 0.251, X2 = 0.548, and X3 = 0.538 for maximum UCS. UCS, mineralogical and microstructural characterization (XRF, XRD, SEM, EDX, FTIR) was performed for the DSM samples prepared considering the optimized components. It was determined that the UCS values of the 3, 7, and 28-day cured samples stabilized by considering the optimum values gave UCS values approximately 3 to 5 times higher than the lower limit values recommended by FHWA. As a result of mineralogical and microstructural investigation, the reason for the strength increase in the samples can be attributed to the formation of geopolymeric gel between the soil particles by tuff waste and fly ash activated with alkaline activator. Carbon footprint analyses were performed for 1m3 DSM columns produced with alkali-activated binders and ordinary Portland cement (OPC). From the analyses it was seen that the carbon footprint of the DSM column produced using alkali activated binders is lower than that of the DSM column obtained with OPC. After the general evaluation of the study, it is seen that the hypothesis that waste tuff can be used as environmentally safe alkali-activated binders instead of traditional binders is supported. © The Author(s), under exclusive licence to Shiraz University 2024.Öğe Optimizing and investigating durability performance of sandy soils stabilized with alkali activated waste tuff-fly ash mixtures(Springer India, 2023) Yilmaz, Fatih; Kuvat, Ahmet; Kamiloglu, Hakan AlperThe search for alternative environmentally-friendly materials to Portland cement is increasing its importance in geotechnical engineering as in other fields. In this study, alkali activated waste volcanic tuff (BT) and fly ash (FA) utilized as an alternative to conventional binders. The specific objectives of this paper were to, (1) optimize fly ash, waste tuff and activator content using Response Surface Methodology (RSM), (2) investigate the UCS performance of the optimum amount of alkali-activated fly ash and waste tuff mixtures as a binder in soil stabilization by comparing with various codes, (3) characterize the optimized parameters, (4) examine durability performances of the samples. Optimum binder and activator content and effect of waste tuff on strength characteristics were evaluated statistically with RSM approach. XRF, XRD, FTIR analyses were performed to verify the synthesized alkali activated material in the inner structures of the optimized samples. The durability and mechanical properties of samples stabilized with alkali activated binders against soaking condition, wetting-drying and were investigated. Destructive and non-destructive methods were employed to examine mechanical and durability characteristics. Unconfined compression strength, strength reduction ratio, soil deterioration, and water absorption capacity was taken into account to evaluate durability performances. UCS values of the stabilized samples were compared with limit UCS values suggested by several standards. As a result of the study it was determined that alkali activated waste tuff and fly ash mixture shows significant mechanical and durability performance in soil stabilization, and capable to use as an alternative to conventional non-green binders.Öğe Usability of midyat stone wastes in soil stabilization(TUBITAK, 2020) Yilmaz, Fatih; Duman, VedatImproving the geotechnical properties of weak soils is described as soil stabilization. In this study, industrial wastes of Midyat stone were used to carry out soil stabilization. Midyat stone wastes, which are evaluated in the improvement of a low plasticity clay soil, were mixed with natural soil at 5%, 10%, 15% and 20% additive percentages. In the light of the data obtained, the presence of a different binder was needed and lime was chosen as the primary binder. Index, strength and durability tests were carried out in mixtures containing 5%, 10%, 15% and 20% Midyat stone waste with and without lime. When the results of the experiments were examined, it was determined that the use of Midyat stone waste as an additive alone was ineffective on strength and durability values. In use with lime, 49% increase in strength has been determined compared to only lime sample. As a result of the study determined that the effect of Midyat stone wastes on freezing-thawing is very limited and more effective on wetting-drying, it was concluded that these wastes can be used for stabilization of low plasticity soils with lime. © 2020, TUBITAK. All rights reserved.
