İnşaat Mühendisliği Bölümü Yayın Koleksiyonu
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Article Citation - WoS: 9Citation - Scopus: 20An Analysis on the Relationship Between Safety Awareness and Safety Behaviors of Healthcare Professionals, Ankara/Turkey(Oxford Univ Press, 2020) Uzuntarla, Fatma; Kucukali, Serhat; Uzuntarla, YasinObjectives: This descriptive study aims to examine the relationship between the safety awareness of healthcare professional and their safety behaviors. Methods: The study was carried out on 418 healthcare professionals working in a training and research hospital in Ankara/Turkey. The survey method was used as data collection tool. The questionnaire consisted of 3 sections and 18 questions. First section consisted of questions on sociodemographic characteristics and, second section consisted of the awareness scale and third section consisted of safety behaviors scale. Results: The safety awareness and safety behaviors are scored on a scale from 1 (completely disagree) to 5 (completely agree). The safety awareness and safety behaviors has an average score of 3.85 +/- 0.81 and 3.56 +/- 0.82, respectively. The safety awareness and safety behavior levels of healthcare professionals were found to be high. Conclusion: A significant positive correlation was found between safety awareness and safety behaviors and it was concluded that the increase in safety awareness led to an increase in safety behavior.Editorial Citation - WoS: 22Citation - Scopus: 26A Dispassionate View of Seismic-Hazard Assessment(Seismological Soc Amer, 2013) Gulkan, PolatArticle Citation - WoS: 30Citation - Scopus: 32Risk Scorecard Concept in Wind Energy Projects: an Integrated Approach(Pergamon-elsevier Science Ltd, 2016) Kucukali, SerhatThe proposed risk assessment tool quantifies economic, environmental, political, and societal risks in wind energy projects. The risks are quantified based on the measured data and document evidence. An important component of the proposed methodology includes converting different external risks into a common scale and these scales express the level of risk factors. A survey was conducted with the experts in order to determine the relative importance of external risks. Applicability of the proposed tool is tested on real time wind power plants that are located in Izmir Province on the Aegean coast of Turkey. Change in laws and regulations, environmental issues, local community, grid connection, land use and permits, and erroneous wind resource assessment appeared to be key risk factors. The findings of case studies showed that the perception of inadequate understanding of the potential risks can lead to significant revenue loss. The proposed method estimates each risk factor level separately and then aggregates them by calculating the Project Risk Score (PRS) which is linked to the normalized revenue loss. (C) 2015 Elsevier Ltd. All rights reserved.Article Citation - WoS: 2Citation - Scopus: 2Effect of Particle Size on Flip Bucket Scour(Canadian Science Publishing, Nrc Research Press, 2016) Kucukali, Serhat; Kokpinar, Mehmet AliThis study quantifies the dimensionless maximum scour depth d(s)/D-50 downstream of flip buckets as a function of the square of the densimetric Froude number Fr-d(2), jet Reynolds number Re, lip angle, and sediment non-uniformity constant. The proposed formula is valid for Fr-d = 2.9-29.69, Re = 8.9 x 10(3)-4.2 x 10(5), and We > 32. Moreover, the scour profiles for different sediment sizes (D-50 = 3-17 mm) are presented from the Kigi Dam physical model and the effect of the Reynolds number on scour process is discussed. The prediction capacity of the proposed formula is compared with the existing empirical formulas in the literature and it is shown that the proposed dimensionally homogenous formula made better estimations. The procedure described here has a sound physical basis and it can be used to estimate the maximum scour depth downstream of flip buckets.Conference Object Article Citation - WoS: 12Citation - Scopus: 12Economic and Environmental Impacts of Utilizing Lower Production Temperatures for Different Bitumen Samples in a Batch Plant(Elsevier, 2022) Almusawi, Ali; Sengoz, Burak; Ozdemir, Derya Kaya; Topal, AliThe utilization of hot mix asphalt (HMA) for road construction necessitates high temperatures during mixing bitumen and aggregate at asphalt plant. The required (mixing) production temperature is calculated by the standard method (ASTM 2493). The application of this method for polymer modified bitumen (PMB) and warm mix asphalt (WMA) have tendency of higher temperatures. Therefore, some alternative methods suggested by literatures for the determination of production temperature for PMB and WMA have been implemented aiming to determine lower temperatures than the standard method (ASTM 2493). Moreover, the economic impacts of the determined production temperatures through different models are evaluated by the estimation of energy consumption in terms of electricity and natural gas costs for the batch type asphalt plants. Besides, the possible environmental effects are calculated by considering the carbon dioxide emissions. The results of this study have shown that the reduction in production temperatures led to a significant decrease in the total construction cost of each type of asphalt and a significant reduction in the estimated carbon dioxide emission. The results of this study can be used as a reference point for the estimation of both economic and environmental impacts of utilizing lower production temperatures for different bitumen samples.Conference Object Performance-Based Seismic Evaluation and Retrofitting of Historic Unreinforced Concrete Wall Buildings With Interior Steel Frames(Dolnoslaskie Wydawnictwo Edukacyjne-dwe, 2012) Gunes, Oguz; Güneş, Oğuz; Gunes, Burcu; Sozenoglu, Ismet; İnşaat MühendisliğiPerformance-based seismic evaluation of historical constructions is a challenge due to the difficulty of their structural analysis that accurately captures their nonlinear behavior. This paper focuses on the use of 3-D nonlinear finite element method for static pushover analysis of unreinforced concrete (URC) wall buildings with interior steel frames for seismic evaluation and retrofit design. Three such historical school buildings with different levels of structural complexity were modeled in detail using advanced finite element programs to obtain their linear and nonlinear behavior under monotonically increasing lateral loads. The capacity curves obtained from pushover analyses were used for performance evaluation using the Capacity Spectrum Method. Retrofit design verification for one of the buildings was performed using the same approach. The results show that despite its involved modeling process and computational expense, pushover analysis of buildings with URC/URM elements using 3-D nonlinear finite element method can become a powerful practical tool for improved seismic performance evaluation and retrofit design.annotation.listelement.badge Closure to "local Scour at Triangular Labyrinth Side Weirs Located on an Alluvial Channel" by Mustafa Tunc, Muhammet Emin Emiroglu, and Mustafa Gogus(2023) Tunç, Mustafa; Emiroğlu, Muhammet Emin; Göğüş, MustafaArticle Effective intake for critical submergence in the case of more than one intake(2017) Taştan, Kerem; Yıldırım, NevzatThe available potential flow solution methods over-estimate the number of effective intake for the prediction of critical submergence in the case of multiple intakes of identical level without partition walls located on the longitudinal line of the canal, because they cannot establish an upper limiting value for the distance between the centers of the intakes. To address this, tests were conducted on dual intakes of identical level located on the longitudinal line of the canal in a cross-flow. In practice, by means of the chart obtained from the experimental results, one can determine the upper limiting value of the distance between the centers of dual intakes beyond which the effect of the intake on the critical submergence of the other intake is negligible. Such an intake is considered a non-effective intake and is disregarded in the prediction of critical submergence. In addition, the effective intake relating to multiple intakes sited in a still-water reservoir is explained.Article Citation - WoS: 8Citation - Scopus: 9Dynamic Shear Force Amplification in Regular Frame-Wall Systems(Wiley-blackwell, 2016) Kazaz, Ilker; Gulkan, PolatA parametric study is conducted to investigate the dynamic shear amplification factor (DAF) in low-to-mid-rise frame-wall systems in which the reinforcement curtailment along the height matches the required code strength. The level of frame-wall interaction is varied by changing the wall index, defined as the ratio of the total wall area to the floor plan area, in a generic frame-wall system, and its correlation with the DAF is investigated. Wall index values ranging in the 0.2% to 2% interval are selected. Walls with lengths of 3m, 5m and 8m are used in the design of model buildings of 4, 8 and 12 stories. Shear-flexure beam continuum formulation is used in design and modeling. The global behavior is analyzed using nonlinear response history procedure using spectrum compatible ground motions. It is found that the primary source of amplification is the level of inelastic demand on the system. Walls designed for code-specified force reduction factor R=6 experienced an average base shear force amplification in the order of 1.64 with standard deviation of 0.19 with respect to design shear force. Amplification diminishes with decreasing R. An expression for the dynamic amplification factor as a function of the number of stories and force reduction factor R is proposed. Copyright (C) 2015 John Wiley & Sons, Ltd.Article Ahşap Bağlantı Noktalarında Mekanik Ankraj Sayısı ve Yerleşim Şeklinin Kayma Gerilmesi-kayma Deplasmanı Davranışı Üzerindeki Etkilerinin Deneysel Olarak İncelenmesi(2021) Acehan, Ayşegül Özden; Mercimek, Ömer; Ghoroubi, Rahim; Anıl, ÖzgürAhşap yapılar ve yapı elemanlarında yapıştırıcı ve mekanik bağlantı elemanları ile bir araya getirilmiş birleşim bölgerinin genel yük-deplasman davranışı, kayma gerilmesi- kayma deplasmanı davranışları, yapısal sistemin kapasitesi ve göçme mekanizmaları üzerinde son derece etkilidir. Ahşap-ahşap bağlantı bölgelerinin davranışları, malzemenin mekanik özelliklerine, yapısına ve türüne göre çok büyük oranda değişim gösteren farklı kayma gerilmesi-kayma deplasmanı davranışları sergileyen, incelenmesi gerekli olan önemli bir konudur. Ahşap yapı elemanlarının yapıştırıcı ve yapıştırıcı ile birlikte mekanik ankrajlar ile birleştirilmesi durumunda genel yük-deplasman davranışlarının, bağlantı bölgesindeki gerilme dağılımları ile kayma gerilmesi - kayma deplasmanı davranışlarının incelendiği kapsamlı bir deneysel çalışmaya literatürde rastlanmamıştır. Bu nedenle deneysel bir çalışma planlanmıştır. Bu çalışma kapsamında birbirlerine yapıştırıcı ve yapıştırıcı ile birlikte mekanik ankrajlar ile bağlanmış olan, kenetlenme uzunlukları 180, 240 ve 350 mm olarak değişim gösteren ahşap bağlantı bölgelerinin, eksenel çekme yükü etkisi altındaki genel yük deplasman davranışları deneysel olarak incelenmiştir. Ayrıca çalışma kapsamında birleşim bölgesinde kullanılan mekanik ankraj sayısı ve yerleşiminin değişim göstermesinin, genel yük-deplasman davranışı ve kayma gerilmesi-kayma deplasmanı davranışları üzerindeki etkileri de araştırılmıştır.Article Su Alma Ağzı Giriş Şeklinin Hava Girişli Çevrinti Üzerindeki Ölçek Etkisi(2018) Taştan, Kerem; Yıldırım, NevzatSu alma ağzı giriş şekli, ağız üzerinde su yüzeyinde oluşabilecek hava girişli çevrintinin karakteristiklerini belirlediğinden ağza ait kritik batıklık üzerinde bazı etkilere sahiptir. Bu etkiler hız dağılımı etkisi ve çevrintiyi besleyen ağız debisi etkisi olarak adlandırılabilir. Bu çalışmada 6 farklı ağız giriş şekline (daire, kare, dikdörtgen, eşkenar dörtgen, eşkenar üçgen, yıldız) ve 40 cm2 ve 100 cm2 olmak üzere iki değişik kesit alanına sahip toplam 12 adet su alma yapısına ait kritik batıklık ve kritik batıklığı etkileyen boyutsuz parametreler (su alma yapısına ait Froude, Reynolds ve Weber sayıları) durgun su ortamında deneysel olarak incelenmiştir. Deney sonuçları neticesinde ağız giriş geometrisinin kritik batıklık üzerinde bir boyut etkisine sahip olduğu görülmüştür. Bu nedenledir ki, her bir farklı ağız giriş geometrisi ve akım şartı, kritik batıklık açısından kendine özgü özellikler taşır. Aynı ağız debisinde farklı su alma ağzı giriş şekillerinin kritik batıklık üzerindeki etkisi ise debi değerine göre değişim göstermektedir.Article Açılı Cfrp Ankrajlı Şeritler ile Beton Yüzey Arasındaki Gerilme Deformasyon Davranışı için Yeni Bir Model Önerisi(2020) Özgür, A. C. Anıl; Ghoroubi, Rahim; Mercimek, ÖmerBetonarme, çelik veya yığma yapılar birçok farklı nedenden dolayı güçlendirilmeleri veya onarılmaları gerekmektedir. Karbon takviyeli elyaf kumaşlar (CFRP) deprem performansı yetersiz yapıların onarım ve güçlendirme çalışmalarında son 20 yıldır yaygın olarak kullanılmaktadır. CFRP ile geliştirilen onarım ve güçlendirme detaylarında önemli olan tasarım kriterlerinden biri CFRP elemanların yüzeyden soyulmalarını geciktirmektir. Bu amaçla CFRP ile geliştirilen güçlendirme detaylarında ankrajların kullanılması artış göstermiştir. Güçlendirme detaylarında kullanılan fan tipi CFRP ankrajlı CFRP şeritler ile ilgili gerilme-kayma deplasmanı modellerinin ankrajsız CFRP şeritlere göre çok daha sınırlı sayıda olduğu görülmektedir. Bu konudaki sınırlı sayıdaki çalışmada ankrajlar CFRP şeritlere uygulanan eksenel çekme kuvvetine göre 90o açılı olacak şekilde yerleştirilmiştir. Yapılan literatür taramasında eksenel yüke göre değişik açılarda yerleştirilen ankrajlı CFRP şeritlerin eksenel kuvvet taşıma gücü ve gerilme kayma deplasmanı modelleri ile ilgili bir çalışmaya rastlanmamıştır. Bu nedenle deneysel bir çalışma düzenlenmiş ve 28 adet beton yüzeyine yapıştırılan açılı ankrajlı CFRP şerit deney elemanı eksenel çekme kuvveti etkisinde yazarlar tarafından tasarlanan bir deney düzeneği kullanılarak test edilmiştir. Deneysel çalışmada incelenen değişkenler CFRP şerit genişliği ve CFRP şeritler üzerindeki CFRP fan tipi ankrajların açılarıdır. Deneysel çalışma sonucunda açılı ankrajlı CFRP şeritlerin maksimum taşıma gücü değerlerinin hesaplanması için bir denklem ve yeni bir gerilme kayma deplasmanı modeli önerilmiştir.Article Citation - WoS: 14Citation - Scopus: 16Experimental and Numerical Investigation of Rc Column Strengthening With Cfrp Strips Subjected To Low-Velocity Impact Load(Techno-press, 2021) Mercimek, Omer; Anil, Ozgur; Ghoroubi, Rahim; Sakin, Shaimaa; Yilmaz, TolgaReinforced concrete (RC) square columns are vulnerable to sudden dynamic impact loadings such as the vehicle crash to the bridges of highway or seaway, rock fall, the collision of masses with the effect of flood and landslide. In this experimental study RC square columns strengthened with and without CFRP strip subjected to sudden low velocity lateral impact loading were investigated. Drop-hammer testing machine was used to apply the impact loading to RC square columns. The test specimens were manufactured with square cross sections with 1/3 geometric scale. In scope of the study, 6 test specimens were manufactured and tested. The main variables considered in the study were the application point of impact loading, and CFRP strip spacing. A 9.0 kg mass was allowed to fall freely from a height of 1.0 m to apply the impact loading on the columns. During the impact tests, accelerations, impact force, column mid-point displacements and CFRP strip strains measurements were taken. The general behavior of test specimens, collapse mechanisms, acceleration, displacement, impact load and strain time relationships were interpreted, and the load displacement relationships were obtained. The data from the experimental study was used to investigate the effect of variables on the impact performances of RC columns. It has been observed that the strengthening method applied to reinforced concrete columns, which are designed with insufficient shear strength, insufficient shear reinforcement and produced with low strength concrete, using CFRP strips significantly improves the behavior of the columns under the effect of sudden dynamic impact loading and increases their performance. As a result of the increase in the hardness and rigidity of the specimens strengthened by wrapping with CFRP strips, the accelerations due to the impact loading increased, the displacements decreased and the number of shear cracks formed decreased and the damage was limited. Moreover, the finite element analyses of tested specimens were performed using ABAQUS software to further investigate the impact behavior.Article Citation - Scopus: 3Strength Prediction of Engineered Cementitious Composites With Artificial Neural Networks(MIM RESEARCH GROUP, 2021) Yesilmen, S.Engineered Cementitious composites (ECC) became widely popular in the last decade due to their superior mechanical and durability properties. Strength prediction of ECC remains an important subject since the variation of strength with age is more emphasized in these composites. In this study, mix design components and corresponding strengths of various ECC designs are obtained from the literature and ANN models were developed to predict compressive and flexural strength of ECCs. Error margins of both models were on the lower side of the reported error values in the available literature while using data with the highest variability and noise. As a result, both models claim considerable applicability in all ECC mixture types. © 2021 MIM Research Group. All rights reserved.Article High-velocity impact of large caliber tungsten projectiles on ordinary Portland and calcium aluminate cement based HPSFRC and SIFCON slabs. Part I: experimental investigations(Techno-Press, 2011) Polat, Gülkan; Korucu, HasanImpact experiments have been carried out on concrete slabs. The first group was traditionally manufactured, densely reinforced concrete targets, and the next were ordinary Portland and calcium aluminate cement based HPSFRC (High performance steel fiber reinforced concrete) and SIFCON (Slurry infiltrated concrete) targets. All specimens were hit by anti-armor tungsten projectiles at a muzzle velocity of over 4 Mach causing destructive perforation. In Part I of this article, production and experimental procedures are described. The first group of specimens were ordinary CEM I 42.5 R cement based targets including only dense reinforcement. In the second and third groups, specimens were produced using CEM I 42.5 R cement and Calcium Aluminate Cement (CAC40) with ordinary reinforcement and steel fibers 2 percent in volume. In the fourth group, SIFCON specimens including 12 percent of steel fibers without reinforcement were tested. A high-speed camera was used to capture impact and residual velocities of the projectile. Sample tests were performed to obtain mechanical properties of the materials. In the companion Part II of this study, numerical investigations and simulations performed will be presented. Few studies exist that examine high-velocity impact effects on CAC40 based HPSFRC targets, so this investigation gives an insight for comparison of their behavior with Portland cement based and SIFCON specimensArticle Citation - WoS: 4Citation - Scopus: 7The Performance of Water Jet Pumps and Their Application in Slurry Transportation(Turkish Soc thermal Sciences Technology, 2023) Kokpinar, Mehmet Ali; Gogus, MustafaThis present work is focused firstly on an experimental investigation for the optimum design of water jet pumps to be used in the hydrotransport of solid particles through pipeline systems. Experiments were conducted in a closed test loop using five types of jet pumps with various dimensions of the driving nozzle, suction nozzle, mixing chamber, and diffuser employing water as driving and suction fluid. The efficiency of each water jet pump element was analyzed and interpretations of results related to each water jet pump were made about the parts to be considered in the optimum design of a water jet pump. From the experimental results, the water jet pump having the optimum mixing chamber, suction nozzle, driving nozzle location, and cross-sectional dimensions produced a maximum efficiency of about 33%. In the second part of the study, the solid particle carrying capacity of water jet pumps in a pipeline system was studied under saltation, moving bed, and heterogeneous flow regimes by introducing seven different types of solid particles having various concentrations into the closed test loop. The effect of jet pumps on separating solid particles from flow in a region was investigated. A curved form of a by-pass system called the 'flow division unit' was added to the main pipeline system and through the flow division unit, then most of the solid particles in the flow were forced to flow towards the suction pipe of the jet pump. As a result of this, only water with very small particle concentrations passed through the centrifugal pumps, and in this way, the wear risk of the centrifugal pump was reduced considerably.Article Citation - WoS: 22Citation - Scopus: 27Measuring Fluid Flow and Heat Output in Seafloor Hydrothermal Environments(Amer Geophysical Union, 2015) Germanovich, Leonid N.; Hurt, Robert S.; Smith, Joshua E.; Genc, Gence; Lowell, Robert P.We review techniques for measuring fluid flow and advective heat output from seafloor hydrothermal systems and describe new anemometer and turbine flowmeter devices we have designed, built, calibrated, and tested. These devices allow measuring fluid velocity at high-and low-temperature focused and diffuse discharge sites at oceanic spreading centers. The devices perform at ocean floor depths and black smoker temperatures and can be used to measure flow rates ranging over 2 orders of magnitude. Flow velocity is determined from the rotation rate of the rotor blades or paddle assembly. These devices have an open bearing design that eliminates clogging by particles or chemical precipitates as the fluid passes by the rotors. The devices are compact and lightweight enough for deployment from either an occupied or remotely operated submersible. The measured flow rates can be used in conjunction with vent temperature or geochemical measurements to obtain heat outputs or geochemical fluxes from both vent chimneys and diffuse flow regions. The devices have been tested on 30 Alvin dives on the Juan de Fuca Ridge and 3 Jason dives on the East Pacific Rise (EPR). We measured an anomalously low entrainment coefficient (0.064) and report 104 new measurements over a wide range of discharge temperatures (5 degrees-363 degrees C), velocities (2-199 cm/s), and depths (1517-2511 m). These include the first advective heat output measurements at the High Rise vent field and the first direct fluid flow measurement at Middle Valley. Our data suggest that black smoker heat output at the Main Endeavour vent field may have declined since 1994 and that after the 2005-2006 eruption, the high-temperature advective flow at the EPR 9 degrees 50'N field may have become more channelized, predominately discharging through the Bio 9 structure. We also report 16 measurements on 10 Alvin dives and 2 Jason dives with flow meters that predate devices described in this work and were used in the process of their development. This includes the first advective measurements in the Lau Basin and at the EPR 9 degrees 39.5'N. We discuss potential error sources and how they may affect the accuracy of measurements by our devices and other devices. In particular, we use the turbulent plume theory to evaluate the effect of entrainment of ambient seawater.Article Citation - WoS: 45Citation - Scopus: 51Risk Assessment of River-Type Hydropower Plants Using Fuzzy Logic Approach(Elsevier Sci Ltd, 2011) Kucukali, SerhatIn this paper, a fuzzy rating tool was developed for river-type hydropower plant projects, and risk assessment and expert judgments were utilized instead of probabilistic reasoning. The methodology is a multi-criteria decision analysis, which provides a flexible and easily understood way to analyze project risks. The external risks, which are partly under the control of companies, were considered in the model. A total of eleven classes of risk factors were determined based on the expert interviews, field studies and literature review as follows: site geology, land use, environmental issues, grid connection, social acceptance, macroeconomic, natural hazards, change of laws and regulations, terrorism, access to infrastructure and revenue. The relative importance of risk factors was determined from the survey results. The survey was conducted with the experts that have experience in the construction of river-type hydropower schemes. The survey results revealed that the site geology and environmental issues were considered as the most important risks. The new risk assessment method enabled a Risk Index (R) value to be calculated, establishing a 4-grade evaluation system. The proposed risk analysis will give investors a more rational basis to make decisions and it can prevent cost and schedule overruns. (C) 2011 Elsevier Ltd. All rights reserved.
