İnşaat Mühendisliği Bölümü Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.11779/1943

Browse

Now showing 1 - 20 of 27

Citation - WoS: 7
Citation - Scopus: 4
2D Modeling Temperature Development of Mass Concrete Structures at Early Age
(FIB. The International Federation for Structural Concrete, 2018) Yikici, T.A.; Chen, R.H.L.
In this paper, a 2D finite volume analysis methodology was used to predict temperature development within three different bridge pier caps. MATLAB® was employed to generate a program that solves the governing heat transfer equation where development of thermo-physical concrete properties was defined as a function of degree of hydration. The rate of heat generation was obtained experimentally via adiabatic calorimetry and the activation energy was determined following the ASTM C 1074 procedure to implement equivalent age concept. 2D finite volume analysis results were presented in comparison with the recorded concrete temperatures from the field. Accordingly, temperature time histories at the center and the side surface of the bridge pier caps were predicted reasonably well using the concrete mixture information and the measured concrete hydration properties. © 2022 Elsevier B.V., All rights reserved.
Contribution of Gravity Frames To Seismic Performance of Steel Moment Resisting Frames
(2018) Zorlu, Mustafa; Şeker, Onur; Akbaş, Bülent; Shen, Jay
Traditionally, lateral stiffness and strength of the gravity frames in steel buildings are neglected in structural analysis. During the past earthquakes, such as Northridge, USA, 1994 and Kobe, Japan, 1995, unexpected failures were detected at beam-to-column connections of steel moment resisting frames (MRFs). In the aftermath of these earthquakes, extensive research has been carried out to reveal the causes of these failures. Based on the detailed observations, it is likely that the reserve capacity provided by the gravity frames prevented the highly damaged steel buildings from collapsing, since majority of the moment-resisting connections failed prematurely during the Northridge earthquake (1994). Even though the influence of gravity frames (GFs) on structural behavior can be substantial, little attention is paid to evaluate its impact on structural response. With this paper, the contribution of interior GFs in seismic performance of special moment resisting steel frames (SMRFs) is evaluated. For this purpose, 4- and 9-story SMRFs were designed in accordance with the requirements of Draft Turkish Seismic Code (2016). The frames are, then, subjected to incremental dynamic analysis. To evaluate the contribution of the interior GFs on the overall seismic performance of structural system, inelastic behavior of shear tab (simple) connections at beam-to-gravity-only columns were idealized as semi-rigid joints. A general purpose structural analysis software, ETABS, is utilized for the analyses. The results of the study are presented in terms of story drifts, base shear vs. roof displacement.
Creating the Flipped Educators of the Future: Leading by Example in the Faculty of Education
(Emerald Group Publishing Ltd., 2016) Kurban, Caroline Fell; Şahin, Muhammed
…
Deprem Yalıtımlı ve Geleneksel Binalarda Tesisatlar İçin Sismik Koruma Hesabı ve Gereksinimi
(2023) Şadan, Bahadır
İnşaat mühendisleri, olası büyük bir deprem senaryosu için, binanın taşıyıcı elemanlarını ve içinde yaşayan insanların can güvenliğini sağlamak için tasarım yapmaktadırlar. Halbu - ki, büyük bir deprem sonrası mali kayıp tabloları incelendiğinde, mali kayıpların en büyük bölümünü yapısal olmayan elemanlardaki hasarın oluşturduğunu görebiliriz. Dışarıdan bakıldığında hasarsız gözüken, taşıyıcı elemanlarında hasar olmayan bir binanın içerisine girildiğinde, sadece kendi ağırlığını taşımak için askılanmış ve doğru sismik koruma uygulan- mamış tesisatların, tavaların ve diğer tavana asılı ekipmanların, yüksek deprem ivmesi nedeni ile hasar gördüğü ve binanın kullanılamaz hale geldiği gözlemlenebilir. Bu durum özellikle deprem sonrası hemen hizmet vermesi gereken kritik binalar için (ör. hastaneler, ulaşım ve haberleşme yapıları vb.) daha büyük önem taşımaktadır. Sağlık Bakanlığı bu bağlamda, 2013 yılında yayınladığı bir genelge ile, 1. ve 2. derece deprem bölgesindeki, 100 ve üzeri yatak kapasiteli tüm devlet hastanelerinde sismik izolatörler ile deprem yalıtımını zorunlu hale getirmiştir. Deprem yalıtımı, binaya etkiyen deprem ivmelerini dolayısı ile deprem kuvvetlerini çok büyük oranda sönümleyerek, sadece bina taşıyıcı siste- minin değil aynı zamanda diğer muhteviyatın (tesisatlar, ivmeye hassas cihazlar vb.) deprem sırasında korunmasını sağlamaktadır. Fakat bu azaltma deprem etkilerini tamamen yok et- mediği için tesisatlarda sismik koruma yapılmasına gerek olmadığı anlamına gelmemektedir. Bu bildiride, 18 Mart 2018, 30364 sayılı Resmi Gazete’de yayınlanarak, 1 Ocak 2019 tarihi itibari ile resmi olarak yürürlüğe giren Türkiye Bina Deprem Yönetmeliği’ne (TBDY) göre elektrik ve mekanik tesisatların sismik koruma hesabı tariflenmektedir. Ayrıca yine TBDY’e göre deprem yalıtımlı binalarda sismik koruma hesabı gereksinimi irdelenmektedir.
Differentiating Flipped Learning Approaches for the Diverse Needs of the Faculty of Economics, Administrative, and Social Sciences
(Emerald Group Publishing Ltd., 2016) Kurban, Caroline Fell; Şahin, Muhammed
…
Fipped Learning Through the Eyes of the Students: Tales and Anecdotes
(Emerald Group Publishing Ltd., 2016) Kurban, Caroline Fell; Şahin, Muhammed
…
Flipped Learning Theory, Policies, and Practices
(Emerald Group Publishing Ltd., 2016) Kurban, Caroline Fell; Şahin, Muhammed
…
Flipping Language, Literature, and Digital Literacies: Stories From the School of Foreign Languages
(Emerald Group Publishing Ltd., 2016) Kurban, Caroline Fell; Şahin, Muhammed
…
From Current Practice To Future Practice: Making the Decision To Flip
(Emerald Group Publishing Ltd., 2016) Kurban, Caroline Fell; Şahin, Muhammed
…
How the Faculty of Engineering Is Developing Its Flipped Approach
(Emerald Group Publishing Ltd., 2016) Kurban, Caroline Fell; Şahin, Muhammed
…
Citation - Scopus: 1
Investigation Procedure for the Diagnosis of Historical Minarets: Inclined Minaret of Sivas Ulu Cami (mosque)
(Springer, 2024) İnci, Pınar; Demir, Cem; Aldırmaz B.; Çoban S.; Halıcı, Ömer Faruk; Cömert M.; Kiraz F.
The inclined minaret of Sivas Ulu Cami (Mosque) from the 13th century Danishmend Period is one of the most invaluable architectural heritages in Turkey. The extent of inclination of the minaret towards the North-West direction, the seismicity of the region, and structural damages that occurred in time have emphasized the need for comprehensive structural and geotechnical investigations. Accordingly, a rehabilitation project is currently going on under the coordination of the General Directorate of Foundations of Turkey. Within the scope of the project, first, a series of field surveys have been conducted to obtain the current features of the minaret including the characteristics of the structural system, damages, deviation from the vertical axis, ground conditions and foundation details. In addition to that, a monitoring system including inclinometers, linear potentiometers and accelerometers has been mounted for tracking the evolution of deformations and damages in time under environmental influences and extracting the dynamic properties of the minaret. Findings from the field survey and monitoring system were used for constructing an analytical model of the structural system of the minaret. Then nonlinear time history analyses were conducted under various strong ground motion records to estimate the seismic performance of the minaret when subjected to earthquakes of different characteristics. The results showed that the tensile stresses that occurred due to seismic actions exceeded the tensile strength of the brick masonry at the region of the transition segment and the cylindrical body (top level of the boot).
Kocaeli 1999 Earthquake, Lessons Learned, Encyclopedia of Earthquake Engineering
(2015) Ural, Derin Nur
...
Laz Rektör Eğitimi Alt Üst Etti
(Pazarlılar Derneği'nin Kültürel Yayını, 2016) Şahin, Muhammed
MEF Üniversitesi Rektörü Prof. Dr. Muhammed Şahin, dünyada hiç bir üniversitede olmayan bir eğitim sistemini üniversitesinde uygulayarak bir ilke imza attı. Bir dönem İTÜ Rektörlüğü de yapan Şahin, Flipped Clasroom eğitim-öğretim modeli ile Türkiye'de eğitimi alt üst ettiklerini söylüyor. Akademi dünyasının tepkisi ise ilginçti: "Bu riski sadece bir Laz Rektör alabilirdi."
Lessons From the Rector of the First Fully Flipped Learning University
(FLR The Flipped Learning 3.0 Magazine, 2018) Şahin, Muhammed
Sahin: MEF Educational Institutions was founded in the 1970s by İbrahim Arıkan, an educator and businessman. In 1996, he founded MEF national and international K-12 schools in Istanbul and Izmir. In 2013, he founded MEF University. As both educator and entrepreneur, Arıkan was in a unique position to establish a university. He was aware the educational system was not well suited to the current needs of students and society and envisioned a totally new educational approach for MEF University. To find this approach, he brought me on board as founding rector. Having been rector of Istanbul Technical University from 2008 to 2012, I had a strong background in innovations in education. During our first meeting, Arıkan made it clear that if he was going to establish a university, it needed to be unique and take a different mentality to the educational needs of today’s students. I vividly remember Ibrahim emphatically declaring that if he could not make a change to higher education, he would call a halt to his aspirations for opening a university.
Citation - WoS: 3
Citation - Scopus: 3
Microzonation With Respect To Ground Shaking Intensity
(CRC Press/Balkema, 2019) Tönük, Gökçe; Kurtuluş, Aslı; Ansal, Atilla
Seismic microzonation is conducted to assess the seismic hazard on the ground surface with respect to ground shaking intensity. A probabilistic seismic hazard study is conducted to define earthquake characteristics on the rock outcrop. A grid system is generated to divide the investigation area into cells according to geological and geotechnical data. Site characterizations are based on available information to define soil profiles for each cell with soil stratifications and shear wave velocities extending down to the engineering bedrock. Site-specific 1D site response analyses are carried out for all soil profiles, based on the engineering properties of encountered soil layers, selection and scaling of the sufficient number of input acceleration time histories compatible with the regional seismicity and earthquake source characteristics. The microzonation study carried out for Zeytinburnu town on the European side of Istanbul with respect to ground shaking intensity is presented. The importance of the selection of the microzonation parameters for assessing ground shaking intensity is discussed. © 2019 Associazione Geotecnica Italiana, Rome, Italy.
Numerical Seismic Performance Investigation of Aac Infill Walls With Flat-Truss Bed-Joint Reinforcement
(National Technical University of Athens, 2023) İlki, Alper; Halıcı, Ömer Faruk
Autoclaved Aerated Concrete (AAC) is a lightweight, energy-efficient and easy-to-transport material. As a result, AAC walls are becoming increasingly common as an infill solution in earthquake-prone areas such as Turkey, Italy, and Greece. Although infills are considered as secondary components in seismic design, they are extremely vulnerable to damage during earthquakes along both in-plane (IP) and out-of-plane (OOP) directions. Previous post-earthquake site examinations revealed that the failure of infill walls can result in serious injuries and casualties. Furthermore, huge economic losses as well as disruption in the functionality of essential buildings that are supposed to be operational after earthquakes may adversely affect the daily life in the earthquake-affected regions. One of the potential methods for increasing the seismic resilience of infill walls is use of bed-joint reinforcement between infill courses. In this paper, the general approaches in the establishment of the numerical finite element model for infill walls with and without bed-joint reinforcement are presented. The developed model was evaluated according to the previous full-scale experimental test results from strength and damage propagation point of view. The model will be used to investigate the response of infills with various bed-joint reinforcement amounts and height-to-length ratios to generalize the seismic performance improvements obtained by the use of flat-truss reinforcement both in the IP and OOP directions.
Observations From Geotechnical Arrays in Istanbul
(2015) Tönük, Gökçe; Kurtuluş, Aslı; Cetiner, Barbaros; Ansal, Atilla
Few small earthquakes with local magnitude slightly larger than M-L = 4 were recorded by geotechnical downhole arrays that have been recently deployed in the west side of Istanbul. Same events were also recorded by Istanbul Rapid Response Network (IRRN) which comprises of 55 surface strong motion stations in the European side of Istanbul. The strongest one of these earthquakes took place on 12/3/2008 in Cinarcik with local magnitude of M-L = 4.8. Even though the observed PGAs were not exceeding 0.01 g, an effort is made to model the recorded response at the downhole array sites as well as the at the IRRN stations using the acceleration records obtained by the deepest sensors, i.e. on the engineering bedrock, at the downhole array sites as input bedrock motions. 1D equivalent linear site response analysis that is generally adopted for site-specific response analysis is used for modelling. Observations from the recorded response and results from 1D modelling of ground response have yielded in general good agreement between the observed and recorded soil response at the station sites.
Citation - WoS: 25
Citation - Scopus: 36
Performance of High-Damping Rubber Bearings for Seismic Isolation of Residential Buildings in Turkey
(Elsevier, 2021) Murota, N.; Tuzun, C.; Mori, T.; Şadan, Bahadır; Wakishima, K.; Suzuki, S.; Sutcu, F.; Erdik, M.
The applicability of high-damping rubber bearings for seismic isolation of residential buildings in Turkey is studied using numerical and experimental approaches. Seismic isolation system composed of high-damping rubber bearings is designed according to the recently updated Turkish Building Seismic Code-2018 (TBSC2018). Three model buildings of different height at assumed seismically active area are chosen from an actual building database, on which, equivalent lateral force procedure, and time history analyses are carried out. The seismic responses of the buildings are evaluated and the seismic isolation system's efficiency is confirmed. It is pointed out that the requirements in the new code in terms of the maximum allowable shear strain of elastomeric isolators are excessively conservative for those isolators with much larger capacity which is verified by sufficient test data, and as a result, designed isolator size becomes larger than necessary from a practical aspect. In order to verify the isolator design without compliance of shear strain limitation in the code, full-scale prototypes of high-damping rubber bearings are specially designed, developed and are subjected to dynamic loading test under test protocol specified in the code. The specific values of test conditions, such as compressive force, shear displacement and frequency, are developed referring several projects in Turkey. The results are comprehensively discussed and the applicability of high-damping rubber bearing for seismic isolation of residential buildings in Turkey is concluded with numerical and experimental approaches and a possible modification of TBSC2018 regarding maximum shear strain is proposed.
Site Characterization for Site Response Analysis in Performance Based Approach
(Sipringer, 2022) Tönük, Gökçe; Ansal, Atilla
The local seismic hazard analysis would yield probabilistic uniform hazard acceleration response spectrum on the engineering bedrock outcrop. Thus, site-specific response analyses need to produce a probabilistic uniform hazard acceleration response spectrum on the ground surface. A possible performance based approach for this purpose requires a probabilistic estimation of soil stratification and engineering properties of encountered soil layers in the soil profile. The major uncertainties in site-specific response analysis arise from the variabilities of (a) local seismic hazard assessment, (b) selection and scaling of the hazard compatible input earthquake time histories, (c) soil stratification and engineering properties of encountered soil and rock layers, and (d) method of site response analysis. Even though the uncertainties related to first two items have primary importance on the outcome of the site-specific response analyses, the discussion in this article focuses on the observed variability and level of uncertainty in site conditions, related to soil stratification, thickness and type of encountered soil layers and their engineering properties, depth of ground water table and bedrock and properties of the engineering bedrock. Thus, one option may be conducting site response analyses for large number of soil profiles produced by Monte Carlo simulations for the investigated site to assess probabilistic performance based design acceleration spectra and acceleration time histories calculated on the ground surface based on 1D, 2D, or 3D site response analysis with respect to different performance levels.
Structural Assessment of the 13th Century Great Mosque and Hospital of Divrigi: a World Heritage Listed Structure
(12th International Conference on Structural Analysis of Historical Constructions (SAHC 2021), 2021) İlki, Alper; Berlucchi, Nicola; Demir, Cem; Şanver, Ali Naki; Hurata, Ali; Cömert, Mustafa; Halıcı, Ömer Faruk
The Great Mosque and Hospital of Divrigi is located in the central eastern partof Turkey, in Divrigi, Sivas. The historical facility consists of a monumental mosque anda two-story hospital, which are adjacent to each other. The structure dates back to13th century Mengujekids period and has been listed by the UNESCO as a World Heritagesince 1985. Great Mosque and Hospital of Divrigi is particularly notable for its monumentalstone portals that are decorated with three-dimensional ornaments carved fromstone. The structural system of the monument consists of multi-leaf stone masonrywalls and stone piers that support the roof structure which consists of stone and brickarches and vaults. The structure is located about 90 km away from the North AnatolianFault Line, that has been causing several destructive earthquakes. Consequently, thestructure is prone to destructive seismic activities. In this study, after a briefintroduction on the structural system and current condition of the structure, thestructural performance of the Great Mosque and Hospital of Divrigi is investigatedthrough site observations and structural analyses. For this purpose, linear and nonlinear 3Dfinite element models of the structure are developed and the structure is examined under theeffects of vertical loads and seismic actions. In the light of the analyses results,recommendations for potential interventions are outlined for further preservation of thestructure.

Browse

Browsing İnşaat Mühendisliği Bölümü Koleksiyonu by Scopus Q "N/A"