İnşaat Mühendisliği Bölümü

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A Case Study of Structural Failure of Mounting Systems for Solar Panels from South-Eastern Turkey: An Investigation of Design Parameters under Extreme Weather Events
(2019) Çelik, Gence Genç; Çelik, O.; 101566; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
One of the biggest demand of growing population, and cornerstone of the socio-economical growth of Nations, Energy is expected today to be Sustainable, Easy to Reach, Economical, and Continuous. As one of the most common and imperative contributors of this Clean Energy Future, Solar Energy in various forms takes a significant role whole around the World. And It shows a great potential particularly for Turkey which imports the majority of its Energy Resources - including Conventional Ones - from Out Sources, to decrease Energy Dependency on Out-of-country Bases and increase awareness to develop competition in New Technology and Production Fields. Based on a Structural Failure Case of Supporting Frames designed for Solar Photovoltaics (PV) in a Solar Power Plant from Turkey, this paper addresses the significance of Local and Site-Specific Investigation of Climate Data to properly decide on Structural Design Parameters -particularly Loads of Snow and Wind- by staying still comformable with National Codes and Standards.
A New Novel Model Proposal For Bond-Slip Behavior Between Angular CFRP Fan Type Anchoraged CFRP Strip and Concrete Surface
(2020) Ghoroubi, Rahim; Mercimek, Ömer; Anıl, Özgür; 306045; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
In the reinforced concrete, masonry or steel structures should be strengthened or repaired. Carbon fiber reinforced polymers (CFRP) have been widely used for the last 20 years for repairing and strengthening of inadequate earthquake performance of the structures. One of the most important developed design criteria in the retrofit and strengthening details are using CFRP to delay the debonding of the CFRP reinforcement elements. For this reason, the uses of anchors in the reinforcement details developed by using CFRP and also researches on this subject have increased substantially. In the literature, research on bond-slip models developed for fan type CFRP anchors and anchored CFRP strips used in reinforcement details are limited in comparison to non-anchored strips. However, in studies on this subject, anchors are placed at 90o to the axial tensile force applied to the CFRP strips. Axial force-bearing strength and bond-slip models of CFRP strips with the different anchored angle under axial tensile strengths have not been found in the literature. For this reason, an experimental study was carried out and 28 specimens of angled anchored CFRP strip test specimen, which was bonded to the concrete surface, was tested under the influence of axial tensile force with an experimental setup designed by the authors. The variables studied in the experimental study are the CFRP strip width and the fan type CFRP anchor angle placed on the CFRP strip. As a result of the experimental study, an equation was proposed for calculating the bearing strength values of angled anchored CFRP strips and a new proposal for the bond-slip model was developed.
A Predictive Ground-Motion Model for Turkey and Its Comparison with Recent Local and Global GMPEs
(2011) Cağnan, Zehra; Akkar, Sinan; Gülkan, Polat; 5743; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
We present a local ground motion prediction equation (GMPE ) for estimating the peak ground-motion values that was derived using the recently compiled Turkish strong motion database . The new GMPE is comparable with the recent global GMPEs in terms of model sophistication and quality of underlying database. Using this equation, we explore the inter-event , inter-station ground motion variability of the recent Turkish strong motion database as well as suitability of some local and global GMPEs for regional seismic hazard assessment analyses. The inter-event error underlines the distinguishing characteristics of few earthquakes, suggesting that the use of local GMPEs can be important especially when specific scenario studies are to be carried out. The inter-station variability allowed us to detect stations with outlier site response and to investigate the goodness of the employed site effect s model. Results also indicate suitability of some global and local GMPEs for use in regional seismic hazard assessments together with the model presented in this study. These should be combined through a logic tree scheme to reduce both aleatory and epistemic uncertainty in local hazard assessments.
Adaptation of generalized Hill inequalities to anisotropic elastic symmetries
(2011) Dinçkal, Çiğdem; 26773; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
Mechanical and elastic behaviors of anisotropic materials are investigated in an innovative way. This is based on generalized Hill inequalities. From different type of anisotropic elastic symmetries, numerical examples are given. Constructing bounds on effective eigenvalues provides a deeper understanding about mechanical behavior of anisotropic materials. Generalized Hill inequalities are adapted to all anisotropic elastic symmetries. The materials selected from the same symmetry type which have larger interval between the bounds, are more anisotropic whereas smaller interval between the bounds, are closer to isotropy. Besides it is proved that there are relations between bulk and shear modulus and eigenvalues of cubic and isotropic symmetry and by these relations, two linear invariants are found out.
An investigation of the hydrodynamic and fish behavior characteristics of the brush-type fish passage: Iyidere (Turkey) field study
(2017) Küçükali, Serhat; 20413; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
Analysis of Elastic Anisotropy of Wood Material for Engineering Applications
(2011) Dinçkal, Çiğdem; 26773; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
This paper presents a convenient method to describe the degree of the elastic anisotropy in a given type of wood and then discusses its practical values. Besides mechanical and elastic behaviour of wood are investigated in order to understand the optimum mechanical behaviour of it in selected directions. Bounds on the wood elastic constants have been constructed in terms of elasticity and compliance tensors for any type of woods by developing Hill (1952) approach. So for any type of wood with known elastic constants, it is possible to choose the best set of elastic constants (effective elastic constants) which determine the optimum mechanical and elastic properties of it. Bounds on the wood elastic constants as well as the degree of elastic anisotropy are significant and critical cases in design of any engineering and structural materials made up of wood.
Citation - WoS: 7
Citation - Scopus: 17
An Analysis on the Relationship Between Safety Awareness and Safety Behaviors of Healthcare Professionals, Ankara/Turkey
(Oxford Univ Press, 2020) Uzuntarla, Fatma; Kucukali, Serhat; Uzuntarla, Yasin; 20413; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
Objectives: 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.
Citation - WoS: 11
Citation - Scopus: 15
Assessment of the Effectiveness and the Initial Cost Efficiency of Hot Recycled Asphalt Using Polymer Modified Bitumen
(Elsevier, 2023) Almusawi, Ali; Shoman, Sarmad; Lupanov, Andrei P.; 01. Çankaya Üniversitesi
The drastic increase in environmental concerns and increasing costs of road construction materials necessitate evaluating some alternative solutions. One of the most suitable alternatives is recycling old asphalt pavement to produce reclaimed asphalt pavement (RAP). The RAP materials have been commonly combined with asphalt mixtures during pavement construction. Incorporating RAP material should demonstrate an equivalent or better performance than conventional asphalt mixtures. Conversely, the inclusion of RAP mainly needs to improve performance compared to conventional asphalt mixtures. The key issue of using RAP is to restore the loss properties of aged materials and normally asphalt Agent Rejuvenator (ARA) was used. Also, adding polymers with RAP into the asphalt mixture becomes necessary to obtain the required performance. This study investigated the RAP effects of elastomeric polymer on the performance of the asphalt mixture following Russian standards (GOST). The impact of using PMB with RAP material on the asphalt mixture's performance was primarily considered by employing tests that can reveal the adhesion property. Additionally, the performance of the pavement was evaluated in terms of strength and low-temperature cracking. For this purpose, numerous test methods were implemented to appraise the asphalt performance, such as compressive strength, moisture susceptibility, shear resistance, tensile strength, porosity of the mineral particles, and residual porosity. The results indicated that the overall performance of the asphalt mixtures prepared with RAP and combined with polymer depicted a better performance. Moreover, the initial construction cost for each asphalt composition was estimated and compared. The utilization of PMB increased the cost of the asphalt mixture. However, such an increase in the cost would lead to an increase in the overall performance, especially for RAP mixtures.
Citation - WoS: 81
Citation - Scopus: 106
Availibility of Renewable Energy Sources in Turkey: Current Situation, Potential, Government Policies and the Eu Perspective
(Elsevier Sci Ltd, 2012) Kucukali, Serhat; Baris, Kemal; 20413; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
This study aims to explore the availability and potential of renewable energy sources in Turkey as well as assessing related government policies, financial and environmental aspects of renewable energy projects. Turkey is a country which has the highest hydropower, wind and geothermal energy potential among European countries. As a European Union (EU) candidate several incentives were developed in Turkey for electricity generation from renewable energy sources by the enactment of Law No. 5346 in 2005 which was later restructured by Law No. 6094 in 2010. The most important ones are: ease of land acquisition and feed-in-tariffs which promise purchasing of electricity generated and domestic manufacturing of equipment by the private companies with a price of 5.30-9.69 and 0.3-2.55 (sic)c/kWh, respectively, depending on the type of the renewable and the equipment. However, feed-in tariff amounts take reservoir area into account instead of installed capacity for hydroelectric power plants. Moreover, Environmental Impact Assessment (EIA) report is not mandatory for all renewable energy plants. According to the multi-criteria analysis tool developed in this study to evaluate the renewable energy source (RES) technologies the most appropriate renewable energy alternative for Turkey is biomass, simply because of the highest social benefit among others. (C) 2011 Elsevier Ltd. All rights reserved.
Citation - WoS: 21
Citation - Scopus: 24
Behavior of Glulam Timber Beam Strengthened With Carbon Fiber Reinforced Polymer Strip for Flexural Loading
(Sage Publications Ltd, 2021) Isleyen, ummu K.; Ghoroubi, Rahim; Mercimek, Omer; Anil, Ozgur; Erdem, Recep Tugrul; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
In the last 20 years, the use of wooden structures and their dimensions have gradually increased. The wood application has increased in different structures such as multistory buildings, sports, industrial facilities, road and railway bridges, power transmission lines, and towers. The widespread use and size of wood structures have increased the research on developing special types of wood products supported by composite materials. Laminated wood elements are the leading composite wood materials. Laminated wooden beams allow making much larger openings than standard solid wood structural elements. The development of the sizes and usage areas of wooden structures has increased the capacity of glulam structural elements and reveals the need to improve their performance. Carbon fiber reinforced polymers (CFRPs) are the most suitable options for increasing the bearing capacity values of glulam beams and improving general load-displacement behaviors. In this study, the use of CFRP strips in different layouts to increase glulam wooden beams and the application of CFRP fan-type anchors in the CFRP strip endpoints are the studied variables. Anchored and non-anchored glulam wooden beams reinforced with CFRP strips with different layouts were tested using a three-point bending test. The ultimate load capacity, initial stiffness, displacement ductility ratio, energy dissipation capacity, failure mechanisms, and general load-displacement behavior of wooden beam test specimens were obtained and interpreted as a result of the experiments.
Citation - WoS: 4
Citation - Scopus: 4
Behaviour of Steel Beams Retrofitted With Anchored Carbon-Fibre Polymer Strips
(Ice Publishing, 2022) Mercimek, Omer; Ghoroubi, Rahim; Baran, Mehmet; Anil, Ozgur; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
Steel bridge beams can be damaged due to increased traffic loads and environmental impacts. An experimental study on the use of bonded and mechanically anchored carbon-fibre-reinforced polymer (CFRP) strips was undertaken to assess the retrofitting of such steel beams. The number of mechanical anchors used in the ends of the bonded strips was varied from zero to eight. The steel beam samples were tested under four-point loading. Loading was applied as an increasingly high static load and a low repetitive fatigue load. The load-displacement behaviour under the effects of static and fatigue loading and the strain distributions along the strips were measured and interpreted. The results showed that retrofitting cracked steel beams with CFRP strips is an effective method. In addition, retrofitting with anchored strips increased the performance of cracked beams under the effects of both static and fatigue loading.
Biogas Energy in Turkey: Current Situation, Sustainability and Policy Implications, Energy Science and Technology
(2014) Bölük, G.; Küçükali, Serhat; 20413; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
Brush-baffle fish pass: a continuous migration corridor for fish
(2016) Küçükali, Serhat; 20413; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
Buildings Subjected to Recurring Earthquakes: A Tale of Three Cities
(2011) Bayhan, Beyhan; Polat, Gülkan; 5743; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
Three different buildings built according to the same design have experienced three different near-field strong ground motions over a period of 11 years in three different cities in Turkey. The input motion was known for each because strong-motion sensors were located adjacent or close to the buildings. We examine the performance of the five-story, reinforced concrete-frame buildings. Bidirectional nonlinear time history and nonlinear static analyses on 3-D analytical models are performed. The principal focus is to assess whether the analytical model of the buildings could indicate column-beam damage consistent with that observed at the sites after the earthquakes. Results illustrate that nonlinear time history analyses are capable of indicating the occurrence of shear failure in captive columns; however, they overestimate the global damage. The overestimation is greater where the building sustained a pulse-type motion without significant distress. It appears that difference between visual observations and analytical results persists.
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, Mustafa; 6062; 01. Çankaya Üniversitesi
Citation - WoS: 6
Citation - Scopus: 7
Crack Width - Seismic Intensity Relationships for Concrete Gravity Dams
(Taylor & Francis Ltd, 2024) Soysal, Berat Feyza; Arici, Yalin; 157572; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
Seismic assessment of plain concrete structures like gravity dams is generally conducted based on cracking. The responses of two types of gravity dams, i.e. the conventional and roller compacted concrete (RCC), were investigated in this study using a discrete element tool coupled with special reservoir elements. Using incremental dynamic analysis, the relationship between the seismic intensity measures and crack widths on the U/S face of the monolith was obtained. The damage accumulation on conventional and RCC dams was different: The cumulative cracking on the upstream face of the monolith correlated well to a seismic intensity measure representing base shear.
Citation - WoS: 3
Citation - Scopus: 2
Critical Submergence for Single and Multiple Horizontal Intake Structures
(Springer Heidelberg, 2023) Gogus, Mustafa; Gokmener, Serkan; 6062; 01. Çankaya Üniversitesi
In this study, a series of experiments were carried out to investigate the variation of the critical submergence of air-entraining vortices with the related flow and geometric parameters at single and multiple horizontal intake structures. Three identical intake pipes were tested at a wide range of discharges with varying sidewall clearances under symmetrical and asymmetrical approach flow conditions. Experimental results indicated that increasing the number of intake structures in operation results in a more complicated flow pattern in front of the intake structures due to the mutual effects of the intakes on each other. Therefore, critical submergence values are higher for multiple intake structures than those of single water intake structures for a given Froude number. Dimensionless empirical equations were derived for each single, double and triple unit operation to calculate the critical submergence as a function of relevant flow and geometric parameters, and they were compared with the related equations available in the literature. These equations can be used to determine sufficient submergence to avoid air-entraining vortices at single and multiple horizontal intakes within the ranges of dimensionless parameters tested in this study.
Cuckoo Search Based Backcalculation Algorithm for Estimating Layer Properties of Full-Depth Flexible Pavements
(Springer, 2021) Öcal, Arda; Pekcan, Onur; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
This book highlights the basic concepts of the CS algorithm and its variants, and their use in solving diverse optimization problems in medical and engineering applications. Evolutionary-based meta-heuristic approaches are increasingly being applied to solve complicated optimization problems in several real-world applications. One of the most successful optimization algorithms is the Cuckoo search (CS), which has become an active research area to solve N-dimensional and linear/nonlinear optimization problems using simple mathematical processes. CS has attracted the attention of various researchers, resulting in the emergence of numerous variants of the basic CS with enhanced performance since 2019.
Citation - WoS: 12
Citation - Scopus: 15
Debris Flow Modelling and Hazard Assessment for a Glacier Area: a Case Study in Barsem, Tajikistan
(Springer, 2023) Dincer, A. Ersin; Kalpakci, Volkan; Ozturk, Sevki; Yilmaz, Kutay; 163874; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
This study analyses a previous debris flow hazard as a consequence of emerging risks related to climate and regional physical changes. In addition to the increasing flood frequencies, there is an increasing risk of mud or debris flow due to increasing temperature and heavy precipitation resulting in glacier melting. One of the most recent dramatic examples of the debris flow incident took place in Barsem, Tajikistan, in 2015. As a result of heavy precipitation and excess temperature, the melting of glaciers caused debris flow which ended up with a catastrophic damage at Barsem Town. In this study, a methodology for modelling debris flow and related hazard is developed by examining the 2015 incident in detail with a commercially available software, Hydrological Engineering Centre-River Analysis System (HEC-RAS). Simulations and hazard assessment of the incident suggest that assessment of debris flow hazard can be implemented similar to flood hazard. Moreover, it is seen that debris flow inundation area can be predicted accurately by low-resolution free-source digital elevation models (DEMs), while in the present work they could not predict the debris flow hazard assessment accurately. Sensitivity results also reveal that free-source DEMs with higher resolutions do not necessarily give better predictions than free-source DEMs with lower resolutions.
Citation - WoS: 23
Citation - Scopus: 30
Deformation Limits for Structural Walls With Confined Boundaries
(Earthquake Engineering Research inst, 2012) Kazaz, Ilker; Gulkan, Polat; Yakut, Ahmet; 5743; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
For accurate analytical assessment of performance and damage in reinforced concrete members, well-defined deformation limits at particular damage states are required. With advanced and computationally intensive finite element analyses, we establish deformation limits at yield and ultimate limit states for adequately confined rectangular reinforced concrete structural walls in terms of drift ratio, plastic rotation, and curvature. To investigate the deformation limits of structural walls, a parametric study on isolated cantilever wall models is performed. The primary variables of the parametric study are the shear-span-to-wall-length ratio, wall length, axial load ratio, normalized shear stress, the amount of horizontal web reinforcement, and the amount of longitudinal reinforcement at the confined boundary of structural wall models. Expressions and limit values are proposed for yield and ultimate deformation capacity of structural walls, based on the most influential parameters. The proposed equations are found to be promising when compared to results of experiments. [DOI: 10.1193/1.4000059]

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