İnşaat Mühendisliği Bölümü Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.11779/1943
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Article Citation - WoS: 10Citation - Scopus: 10Site Response Analysis in Performance Based Approach(Elsevier Sci Ltd, 2024-03-01) Ansal, Atilla; Tönük, Gökçe; Sadeghzadeh, Shima; Sadegzadeh, ShimaA performance based approach for site response analysis requires a probabilistic approach accounting for the observed variability in soil stratification and engineering properties of the soil layers. The major variability in site-specific response analysis arises from the uncertainties induced by the (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 item, local seismic hazard assessment, has primary importance on the outcome of the site-specific response analyses, the discussion in this article focuses on the possible uncertainties in selection and scaling of the hazard compatible input earthquake time histories, soil stratification, thickness, type and their engineering properties, depth of ground water table and bedrock and properties of the engineering bedrock. One alternative may be to conduct site response analyses for large number of soil profiles generated by Monte Carlo simulations using relatively large number of hazard compatible acceleration time histories to assess probabilistic performance based design acceleration spectra and acceleration time histories calculated on the ground surface with respect to different performance levels. A remaining issue may be considered as the variability induced by 1D, 2D, and 3D site response analysis.Conference Object Numerical Seismic Performance Investigation of Aac Infill Walls With Flat-Truss Bed-Joint Reinforcement(National Technical University of Athens, 2023) İlki, Alper; Halıcı, Ömer FarukAutoclaved 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.Article Citation - WoS: 10Citation - Scopus: 16Out-Of Seismic Performance of Bed-Joint Reinforced Autoclaved Aerated Concrete (aac) Infill Walls Damaged Under Cyclic In-Plane Displacement Reversals(Elsevier Sci Ltd, 2023-07-01) İlki, Alper; Demir, Uğur; Halıcı, Ömer Faruk; Zabbar, YassinThe infill walls made of Autoclaved Aerated Concrete (AAC), which is a lightweight, fire resistant and energy efficient material, provide effective insulation solutions for building types of structures and becoming more and more popular in earthquake prone regions. Although the number of experimental tests examining the seismic response of clay brick infills is extensive, the amount of prior research on infill walls built of AAC blocks is rather limited. Past research revealed that the use of bed-joint reinforcement is one of the promising solutions to improve the global seismic response of masonry walls by enhancing strength and displacement capacity. In this study, the out-of-plane (OOP) seismic performance of AAC infill walls with flat-truss and innovative cord-type bed-joint reinforcement is experimentally evaluated. Also, consideration is given to the prior in-plane (IP) damage, which was found to degrade the seismic performance of infills in OOP direction. For this purpose, three IP and four OOP, in total, seven experimental tests were performed on four full-scale AAC infill wall specimens. The test parameters were selected in such a way as to make it possible to parametrically compare the OOP performance of AAC infills with flat-truss and cord-type bed-joint reinforcements with unreinforced AAC infill walls, together with the effect of prior IP damage on the OOP response of unreinforced AAC infill walls. It was found that the use of innovative cord-type bed-joint reinforcement improved the OOP strength to a similar extent to what was obtained from the truss-type reinforced specimen. In terms of ultimate displacement and energy dissipation capacity enhancement, the specimen with cord-type reinforcement performed better. In addition, the damages formed due to IP cyclic displacement reversals up to 0.005 drift ratio, which is defined as the drift limit for buildings with brittle infill walls in certain design codes, resulted in a significant reduction in the OOP strength and stiffness properties of AAC infills. The theoretical OOP strength calculations were found to provide unconservative strength values for the IP-damaged specimens.Article Citation - WoS: 12Citation - Scopus: 13Damage Accumulation Modelling of Two Reinforced Concrete Buildings Under Seismic Sequences(Springer, 2023-06-30) Tönük, Gökçe; Oyguç, Reşat; Oyguç, Evrim; Uçak, DorukThe extent of earthquake damage depends solely on the seismicity, site conditions and vulnerability of the building stock in a region. Hence, studies to assess the seismic behavior of building stocks with similar vulnerabilities are important to mitigate seismic risk in earthquake-prone regions. This study aims to simulate the seismic behavior of selected reinforced concrete (RC) school buildings by modelling damage accumulation under multiple earthquakes sequence. The observed data of two RC school buildings heavily damaged after the 2011 Van earthquake sequence in Turkey, namely, the Gedikbulak and Alakoy schools is used. Among these two school buildings, the Gedikbulak school building collapsed immediately after the main excitation, while the Alakoy school building withstood several seismic sequences, suffering heavy damages. In this study, three-dimensional numerical models that can consider the deterioration effects are developed and the capacities of the buildings were evaluated by conducting a force-based adaptive pushover procedure. Additionally, non-linear dynamic analyses were conducted using the concrete plastic damage model. Both degrading and conventional material models were used to examine the structural response under multiple ground motion sequences. The hysteretic behaviors of the studied buildings are presented. Consequently, analytical results are well correlated with the reconnaissance studies and neither of the considered structures are found to satisfy the design performance level.Conference Object Citation - Scopus: 3Wireless Real-Time Monitoring System for Steam Cured Concrete Maturity Calculation(IEEE, 2021-10-06) Bekmezci, İlker; Sürücü, Engin; Yıkıcı, AlperInternet of Things (IoT) enabled LoRaWAN® system is adopted to monitor concrete temperatures in real-time via wireless devices embedded within concrete cover. Maturity method is employed to predict compressive strength development of steam cured precast concrete segments produced at an automated manufacturing plant using carousel system. The concrete segments embedded with IoT devices are exposed to steam curing in thermally insulated chambers and transferred to the evacuation line outside of the plant after being demolded. Real-time temperature measurements are continuously compared to predefined target values, so that an email notification could be send to production engineer. In this study, concrete temperatures as well as curing ambient temperatures for two different cases during segment manufacturing are successfully recorded. The details of IoT wireless system to estimate the strength of concrete are presented.Article Citation - WoS: 30Citation - Scopus: 45Performance of High-Damping Rubber Bearings for Seismic Isolation of Residential Buildings in Turkey(Elsevier, 2021-04-01) 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.Article Citation - WoS: 5Citation - Scopus: 6Gis-Based Assessment of Seismic Vulnerability Information of Old Masonry Buildings Using a Mobile Data Validation System(American Society of Civil Engineers (ASCE), 2021-06-01) Özsoy Özbay, Ayşe Elif; Ünen, Hüseyin Can; Karapınar, Işıl Sanrı; Ozbay, Ayse Elif ozsoy; Sanrl Karaplnar, Işll; Sanri Karapinar, IsilThis study proposes a geographic information system (GIS)–based rapid visual screening approach for seismic vulnerability assessment of masonry buildings in culturally and architecturally important historical regions. Through the application of the proposed methodology, a prioritization strategy for seismic vulnerability assessment of the heritage masonry buildings in Galata, a historical center of Istanbul, Turkey, was performed. This approach is based on an integrated methodology including a data collection process conducted through visual inspections and standard survey forms filled on site, generation of a georeferenced building database enabling the calculations and mapping of the vulnerability scores, and camera-based data validation process. The validation process provides an online collaborative mobile mapping system through georeferenced images gathered from the field. By the updatable data validation process, the reliability and efficiency of the GIS-based building database are enhanced by minimizing the errors during the visual screening and the cost of data correction due to reinspection is reduced.Article Citation - WoS: 4Citation - Scopus: 7Modal Identification of the First Bosporus Bridge During Hanger Replacement(Taylor & Francis, 2020-01-30) Dikmen, Seyyit Ümit; Aytulun, Emre; Luş, Hilmi; Safak, Erdal; Soyöz, Serdar; Apaydın, NurdanAs the oldest of the three suspension bridges spanning the Bosporus, the (First) Bosporus Bridge wascommissioned in 1973. Its main span of 1074 m was originally designed to be suspended by inclinedhangers; in 2015, the original inclined hangers were replaced by vertical ones. In-situ ambient vibra-tion measurements were taken at different stages of this operation to gain an understanding of theeffects of the hanger cable orientation on the overall dynamic behaviour of the bridge. Measurementswere also recorded for various periods spanning several weeks to observe operational variations onthe modal frequencies of vibration. Measurements were made on the tower, the deck and the hang-ers. It was observed that, as a result of the hanger replacement, frequencies of the modes involvingpredominant deck motion decreased on the order of 6 to 16% while the frequencies of the modesinvolving predominant tower motion showed almost no change. A finite element model of the Bridgewas also developed to further investigate the physical reasons behind the observed changes in modalfrequencies and similar trends were observed in the modal frequencies yielded by the finite elementmodels developed for the inclined and the vertical hanger configurations.Book The New University Model : Flipped, Adaptive, Digital and Active Learning (fadal)(FL Global Publishing, 2019) Şahin, Muhammed; Kurban, Caroline Fell; Mazur, EricThis book is the academic version of The New University Model with an added focus on Adaptive, Digital and Active Learning (FADAL) and a future perspective on higher education. You can learn about flipping a lesson or class from many educators, but only a few people in the world have experienced flipping multiple university departments or an entire university. What could you learn from spending a few hours with the authors who have deep insight into the process of starting, managing, and scaling Flipped Learning in higher education? MEF University is the first fully flipped university in the world. The 2018 graduating class included students who earned their degrees through Flipped, Adaptive, Digital and Active Learning programs in: mathematics education, guidance and psychological counselling, law, computer engineering, electronics and electrical engineering, industrial engineering, civil engineering, mechanical engineering, economics, business administration, psychology, political science and international relations, architecture, and interior design. In this book, MEF’s rector and the director of the Center for Research and Best Practices in Learning and Teaching share invaluable insights that are not available anywhere else. Whether you are a professor considering flipping your class, a dean or a department head considering expanding your Flipped Learning program, or a rector, president or provost looking for a future perspective on higher education, this book will put you on a clear and proven fast track. The book also includes the framework and set of best practices recently developed by the Academy of Active Learning Arts and Sciences (AALAS) through a cohort of 100 experienced Flipped Learning practitioners in 49 countries. The framework will help you avoid the big mistakes as you embrace and scale Flipped, Adaptive, Digital and Active Learning in higher education. “The book is a must-read for any innovative educator or higher education administrator.” -- Dr. Eric Mazur, School of Engineering and Applied Sciences and School of Education, Harvard University.Book The New University Model : Scaling Flipped Learning in Higher Education(FL Global Publishing, 2019) Şahin, Muhammed; Kurban, Caroline Fell; Mazur, EricYou can learn about flipping a lesson or class from many educators, but only a few people in the world have experienced flipping multiple university departments or an entire university. What could you learn from spending a few hours with the authors who have deep insight into the process of starting, managing and scaling Flipped Learning in higher education? MEF University is the first fully flipped university in the world. The 2018 graduating class included students who earned their degrees through Flipped Learning programs in: mathematics education, guidance and psychological counselling, law, computer engineering, electronics and electrical engineering, industrial engineering, civil engineering, mechanical engineering, economics, business administration, psychology, political science and international relations, architecture, and interior design. In this book, MEF’s rector and the director of the Center for Research and Best Practices in Learning and Teaching share invaluable insights that are not available anywhere else. Whether you are a professor considering flipping your class, a dean or a department head considering expanding your Flipped Learning program, or a rector, president or provost considering expanding your Flipped Learning program, this book will put you on a clear and proven fast track. The book also includes the framework and set of best practices recently developed by the Academy of Active Learning Arts and Sciences (AALAS) through a cohort of 100 experienced Flipped Learning practitioners in 49 countries. The framework will help you avoid the big mistakes as you embrace and scale Flipped Learning in higher education. “The book is a must-read for any innovative educator or higher-education administrator.” -- Dr. Eric Mazur, School of Engineering and Applied Sciences and School of Education, Harvard University.