İnşaat Mühendisliği Bölümü Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.11779/1943
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Conference Object Citation - WoS: 7Citation - Scopus: 22D Modeling Temperature Development of Mass Concrete Structures at Early Age(fib. The International Federation for Structural Concrete, 2017) Yikici T.A.; Chen R.H.L.; Chen, Roger H. L.; Yikici, Tahsin AlperIn 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. © Springer International Publishing AG 2018.Conference Object Citation - WoS: 1Citation - Scopus: 1A Simplified Approach for Site-Specific Design Spectrum(Springer, 2017) Tönük, Gökçe; Kurtuluş, Aslı; Ansal, AtillaThe design acceleration spectrum requires site investigations and site-response analyses in accordance with the local seismic hazard. The variability in earthquake source and path effects may be considered using a large number of acceleration records compatible with the earthquake hazard. An important step is the selection and scaling of input acceleration records. Likewise, a large number of soil profiles need to be considered to account for the variability of site conditions. One option is to use Monte Carlo simulations with respect to layer thickness and shear wave velocity profiles to account for the variability of the site factors. The local seismic hazard analysis yields a uniform hazard acceleration spectrum on the bedrock outcrop. Site-specific response analyses also need to produce a uniform hazard acceleration spectrum on the ground surface. A simplified approach is proposed to define acceleration design spectrum on the ground surface that may be considered a uniform hazard spectrum.Other Aktif Öğrenme Modelini Kullanan Mef Üniversitesi’nin İddiası: “öğrenmede Sınırsız Özgürlük”(KobiEfor, 2020) Şahin, MuhammedMEF Üniversitesi, yüksek öğretimde dönüşümün anahtarı olarak kabul edilen Flipped Learning modelini ilk uygulayan kurum olarak ilk mezunlarını 2018’de verdi. Aktif öğrenme modelinde yetişen öğrencilerin mezuniyet sonrası işe girme ve öğrenime devam etme oranı yüzde 96’yı buldu. Üniversite bu yıl da finalleri kaldırarak proje haftasını getirdi.Conference Object Citation - WoS: 2Citation - Scopus: 3An Overview on the Structural Monitoring, Assessment and Retrofitting of Historical Structures With a Focus on 13th Century Monuments(Springer international Publishing Ag, 2024) Ilki, Alper; Inci, Pinar; Halici, Omer F.; Demir, Cem; Comert, Mustafa; Kuran, FikretMonumental historical structures affirm natural and cultural identity and hence they should be transmitted to future generations. The protection and preservation of these structures against aging and natural hazards, particularly seismic actions, requires a comprehensive approach including diagnosis of the present condition of the structure and enhancement of structural capacity for disaster mitigation, if necessary. It is obvious that due to their historical values, any attempt towards the preservation of the monumental historical structures must be carried out with respect to the principles of integrity and authenticity. In this study, the structural performance assessment procedures, implementation of structural health monitoring systems and seismic strengthening strategies are discussed and described with reference to 13th-century monumental historical structures in Turkiye. The structural engineering aspects of recent activities for the restoration and preservation of the Great Mosque and Hospital of Divrigi (a world heritage listed structure) and Sivas Ulu Cami (Mosque) Minaret are briefly presented. In light of the structural analysis and monitoring results, recommendations for interventions to these monumental structures are outlined.Article Citation - WoS: 4Citation - Scopus: 4Assessment of the Disaster Recovery Progress Through Mathematical Modelling(TMMOB İnşaat Mühendisleri Odası, 2020) Dikmen, Seyyit Ümit; Sönmez, Murat; Akbıyıklı, Rıfat; Umit Dikmen, S.Natural disasters, especially major earthquakes, cause widespread devastation in the built environment. Hence, the major component of the recovery in its aftermath constitutes a chain of projects starting at different times, having different costs and durations. In this study, the post disaster recovery curve modelled through a mathematical approach taking into account these properties of the projects. The approach followed is based on the project S-curve concept that provides the opportunity to simulate the progress by outlining the project spending. Well-known mathematical functions are adapted to model the project spending and the handover processes. Monte Carlo simulation is performed to evaluate the general behavior of the recovery curve using the model developed. Weibull distribution is used to generate the model’s parameters. Results of the Monte Carlo simulation demonstrate that the recovery process exhibits an S-shape, the duration of initial portion and the slope of the bulk portion being significantly governed by the level of preparedness of the community.Article Bitişik Yapıların Deprem Performanslarının Ayrı veya Bitişik Olarak Kırılganlık Eğrileri Yardımı ile İncelenmesi(Gazi Univ, 2015) Akbulut, Ali; Boduroğlu, M. HasanMevcut yapıların deprem performans, risk ve güçlendirme analizlerinde, yanındaki yapı ile olan ilişkisini uygun modelleme teknikleri ile analiz aşamasının içine dâhil ederek, sonuçların tekbaşına analiz edilmiş binalara göre olan farklılıklarını incelemek önemli bir konu olarak ortaya çıkmaktadır. Bu çalışmada, literatürdeki komşu binaların birbirleri ile olan etkileşim modelleri, statik itme analizi ve doğrusal olmayan hesap yöntemleri, deprem ivme kayıtlarının bir veri tabanından alınması ve tasarım spektrumuna göre ölçeklenmesi, zaman tanım alanına göre hesap yöntemi, hareket denkleminin Newmark-b yöntemi ile sayısal çözümü ve kırılganlık eğrileri ile bina performans seviyelerinin belirlenmesi konuları incelenmiştir. Bitişik (komşu) ve birbirine benzer binaların, deprem performanslarının birbirileri ile olan etkileşimli ve deprem yönüne göre değişen bir şekilde yapı blokları olarak ele alınıp, hasar görebilirlik-kırılganlık eğrileri yönünden değerlendirilmeleri incelenmiş ve binaların ayrı ayrı analiz edildikleri duruma göre daha farklı sonuçlar verdiği tespit edilmiştir.Article Citation - WoS: 7Citation - Scopus: 7Case Study on Seismic Behavior of Aseismically Designed Reinforced Concrete Frame Structures(Springer, 2017) Oyguc, Evrim; Oyguc, Resat; Tönük, GökçeIn this study, the seismic performances of two aseismically designed plan-irregular reinforced concrete frame (RCF) households damaged during the October 23, 2011 Van earthquake are assessed. Since no strong ground motion recordings from the main shock were available, first, strong ground motion parameters of the event are evaluated and then compatible with these parameters suits of real records are selected and scaled to match with the event's simulated acceleration spectrum to be used in the analytical investigations. The results of previous reconnaissance studies, in which one of the present authors was involved, are then discussed. Capacities of the considered RCF's are determined applying a 3D single-run adaptive pushover procedure that is capable of considering the effect of plan irregularities. The performance assessment procedure based on the current 2007 Turkish Earthquake Code is then applied to these investigated buildings. Additionally, nonlinear dynamic time history analyses are carried out using the previously selected time histories. The hysteretic behavior of the considered buildings is examined as the consequence of the conducted analyses and considering the different suits of selected ground motions, the seismic response of the buildings is evaluated in terms of interstorey drifts. None of the buildings are found to satisfy the expected performance level. Moreover, the numerical results are found to have good correlation with the field observation results.Conference Object Citation - WoS: 1Citation - Scopus: 2Compaction and Shear Strength Behavior of Fresh and Aged Basic Oxygen Furnace (bof) Steel Slag(Amer Soc Civil Engineers, 2016) Yıldırım, İrem Zeynep; Prezzi, MonicaUse of industrial by-products in geotechnical engineering projects, such as in the construction of highway embankments, is advantageous because large volumes of these materials can be utilized. Basic oxygen furnace (BOF) steel slag is one of these industrial by-products. This paper provides a brief background on the characteristics of BOF steel slag and presents the results of a series of laboratory tests (grain-size analysis, maximum and minimum dry density, compaction, large-scale direct shear tests (LDS) and isotropically consolidated-drained triaxial compression (CID TX) performed on fresh and aged BOF steel slag generated from an Indiana steel plant. BOF steel slag samples from three different batches of production were tested, which allowed an evaluation of both aging processes and the effect of changes in gradation on the mechanical properties. The BOF steel slag tested in this study contained sand-size particles with varying percentages of gravel-and silt-size fractions. The moisture-density relationships for BOF steel slag were irregular with two peaks. Based on the LDS and CID TX test results, the BOF steel slag exhibited superior strength and stiffness characteristics than conventional geo-materials. The mechanical properties of fresh and aged BOF steel slag are discussed in the context of its use in geotechnical applications.Book Part Comparison of the Observed and Numerical Performance of a Seismic Isolated Hospital(International Association for Earthquake Engineering, 2024) Şadan, B.; Sahin, B.; Tüzün, C.; Demircioglu-Tumsa, M.B.; Erdik, M.; Demircioglu Tumsa, M.B.The southeastern region of Turkiye was struck by powerful earthquakes on February 6, 2023, with magnitudes measuring M7.7 and M7.6. These earthquakes resulted in significant damage, destruction, and loss of life, affecting both Türkiye and extending into northern Syria. Among the approximately 100 isolated buildings in Turkiye, 11 isolated hospitals were located in the impacted region. This paper presents a comprehensive assessment of the seismic performance of the seismically isolated Osmaniye State Hospital during the Kahramanmaras earthquakes. The evaluation comprises site observations and numerical analysis utilizing ground motion records obtained from the nearest accelerometers. Site observations involved monitoring the movements of the isolators located at the moats around the perimeter of the hospital. Using a borescope allowed for detailed internal inspection of the isolation bearings, facilitating close-up examination of the isolators and enabling the identification of movement scuff marks on the sliding surfaces. These observations were used to estimate the maximum isolation bearing movement and determine the residual displacement offset of the bearings. The observed displacements of the isolation system were compared with the design values to assess the performance of the seismically isolated structure. Discrepancies between the observed and designed displacements provide valuable insights into the actual behavior of the isolation system. A nonlinear time history analysis was conducted using ground motion records obtained from the nearest accelerometers to further analyze the seismic response. This numerical analysis allowed for the simulation of earthquake excitations and the evaluation of the dynamic behavior of the seismically isolated Osmaniye State Hospital. The combination of site observations and numerical analysis yielded important findings regarding the seismic performance of the seismically isolated Osmaniye State Hospital during the Kahramanmaras earthquakes. The comparison between observed and design displacements provided insights into the efficacy of the isolation system, while the numerical analysis further validated the structural response. These findings contribute to improving the design and implementation of seismically isolated structures. © 2024, International Association for Earthquake Engineering. All rights reserved.Article Contribution of Gravity Frames To Seismic Performance of Steel Moment Resisting Frames(2018) Zorlu, Mustafa; Şeker, Onur; Akbaş, Bülent; Shen, Jay; Boz, MehmetTraditionally, 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.