Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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Author: search.filters.author.Dönmez, C.Publisher: search.filters.publisher.International Association for Earthquake Engineering

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  • Book Part
    Lessons From the 2023 Southeast Türkiye Earthquakes: A Study on Damaged RC Buildings Considering the Hassan Index
    (International Association for Earthquake Engineering, 2024) Dönmez, Cemalettin; Dowgala, J.; Eryimaz-Yildirim, M.; Güllü, M.F.; Iturburu, L.; Koroglu, F.B.; Speicher, M.S.; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    A survey was conducted across 10 cities in Southeast Türkiye to classify damage in 242 reinforced concrete (RC) buildings constructed in the last 15 years, ranging from 2 to 16 stories. The ‘robustness’ of these buildings was quantified using ratios of cross-sectional areas of vertical elements (walls and columns) to floor-plan areas. The results are compared with similar measures obtained for buildings in Erzincan and Duzce (Türkiye) and buildings in Chile and Japan as well. These comparisons suggest that excessive drift was one of the primary causes of the widespread damage in RC buildings across the cities surveyed, from Antakya to Malatya. Drift a) exposed a myriad of defects in structural layouts and reinforcing detailing, b) caused nearly destruction of partitions and other non-structural building components (leading to disruptions of functionality even in the absence of structural damage), and c) induced instability even in structures with better detailing. In contrast, stiff (albeit uncommon) structures with abundant and well-distributed structural walls had lower drifts and performed well. Except for sporadic failures in details placed at critical locations, those structures are still in use and should serve as models for reconstruction. © 2024, International Association for Earthquake Engineering. All rights reserved.
  • Book Part
    A Novel Approach for Addressing Interstory Drift Concentrations in Eccentrically Braced Frames
    (International Association for Earthquake Engineering, 2024) Dönmez, Cemalettin; Dönmez, C.; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Drift concentrations under seismic demands are accepted to be a natural phenomenon by the profession. In typical steel eccentrically braced frame (EBF) design, drift concentrations cause systems to reach their material limits at lower roof drift ratios and plastic link beam rotations to exceed permissible limits. As an attempt to demonstrate that concentrations are not natural, but rather the result of the design decisions, an algorithm to modify the drift distribution in EBFs has been developed. The developed method uses an iterative post-processing algorithm to manipulate the post-elastic modal vectors of the EBFs for distributing the interstory drift ratios uniformly and mitigating the possible drift concentrations. The algorithm proved to be effective in both design-basis earthquake (DBE) and maximum considered earthquake (MCE) demands. The initial verifications have been done through sensitivity analyses of various types of EBFs by nonlinear time-history analyses. The parameters considered are the number of stories (representing low-and mid-rise EBFs), the link length to bay width ratios (e/L), and the first story height to typical story height ratios. Results obtained demonstrated that the story shear distribution of the revised frames, which exhibited well-distributed interstory drifts, had consistent shapes markedly different from the distributions of equivalent lateral force procedures. Furthermore, base shear capacity is observed to be an important metric to be considered during the design stages. The algorithm is demonstrated by a benchmark building selected from the literature. The seismic performance of the building is enhanced through the utilization of the developed algorithm, and the outcomes are evaluated with respect to the designated metrics. The initial and ongoing observations based on the sensitivity analyses indicate the potential contributions of the developed algorithm to the efficient design of EBFs. © 2024, International Association for Earthquake Engineering. All rights reserved.
  • Book Part
    Brief Recommendations Addressing RC Buildings Affected by Earthquakes
    (International Association for Earthquake Engineering, 2024) Dönmez, Cemalettin; Dönmez, C.; Irfanoglu, A.; Ozturk, B.; Pujol, S.; Shah, P.; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Because of the past experience in Christchurch, New Zealand, where many reinforced concrete (RC) buildings without critical damage have been demolished after earthquakes, and similar events elsewhere, FEMA and ATC are preparing comprehensive guidelines on how to address an RC building after it undergoes strong ground motion. Those guidelines should be the primary resource for practicing engineers wherever building authorities adopt them. The guidelines are being designed to fit well within the regulatory seismic assessment framework used in the United States and are based on terms and methods defined by ASCE (ASCE, 2017). The recommendations presented here are intended to be a simpler alternative that could help engineers elsewhere and expedite the assessment of RC buildings after a strong earthquake. These are the opinions of the writers. Previous research by Cecen (1979), FEMA 307 (1998), Shah (2021), Monical (2021), and ATC (2021) has shown that well-detailed RC buildings can survive repeated earthquakes without negative changes in performance as long as the effects of the initial motion(s) are limited to flexural cracking, shear cracking controlled by transverse reinforcement, and flexural yielding. These phenomena a) tend not to cause reductions in structural resistance and, consequently, b) tend not to cause increases in earthquake deformation demands either. Nevertheless, after every strong earthquake, scores of RC buildings are questioned throughout the world, even in the absence of critical structural damage. At the same time, too many RC buildings around the world end up being demolished because of earthquake damage to facades, partitions, finishes, and other non-structural building components. These recommendations are presented here as a simplified approach and an alternative to address both of these problems. The recommendations include building interventions of different natures and extents to address both brittle and ductile existing buildings and consider the implications of initial damage on the future performance of both the structure and non-structural components. © 2024, International Association for Earthquake Engineering. All rights reserved.
  • Book Part
    Seismic Performance of RC Buildings With Wide-Beams During 2019 Albania and 2023 Türkiye Earthquakes
    (International Association for Earthquake Engineering, 2024) Dönmez, Cemalettin; Isufi, B.; Marinković, M.; Dönmez, C.; Pinho Ramos, A.P.; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    The performance of concrete buildings with concealed wide beam floors is in focus in this paper. These types of buildings were highly affected and damaged during the Albania, November 26th, 2019 and the Türkiye, February 6th, 2023 earthquakes. This typology has been widely used in Albania after ’90 and in Türkiye since the ’60s, and it can be found in buildings with different heights, from low to high rise. In cases of low to mid-rise buildings, wide beam–column frames are predominant, whereas, in high-rise buildings, wide concealed beams are present in both moment frame and dual RC systems. Moreover, such structural systems remain the most used in Albania even nowadays, almost five years after the aforementioned strong earth-quake. This paper aims to review the seismic performance of buildings with concealed wide beams in light of the new field data gathered following the 2019 Albania and 2023 Türkiye earthquakes. Data from field visits in Albania and Türkiye are described and discussed. It was found that damage in Albania to the joisted slabs and concealed beams was limited, but the disadvantages of the system were expressed through damage mostly concentrated in other structural elements such as columns or non-structural masonry infill. Damages in Türkiye were more extensive. An investigation of the possible explanations for these observations is presented based on nonlinear analyses performed on two case study buildings. Finally, the implications of the results of the analyses for the seismic performance of RC buildings are discussed and confronted with earthquake damage observations. © 2024, International Association for Earthquake Engineering. All rights reserved.