Civil Engineering / İnşaat Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/13
Browse
5 results
Search Results
Article Citation - WoS: 38Citation - Scopus: 43Quantitative Evaluation of the Damage To Rc Buildings Caused by the 2023 Southeast Turkey Earthquake Sequence(SAGE Publications, 2024) Pujol, Santiago; Dönmez, Cemalettin; Dönmez, Cemalettin; Dowgala, Jeffrey D.; Eryılmaz Yıldırım, Meltem; Klaboe, Kari; Köroğlu, Fahri Baran; Lequesne, Rémy D.; Öztürk, Baki; Pledger, Liam; Sönmez, Egemen; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyData from 15 earthquakes that occurred in 12 different countries are presented showing that, without better drift control, structures built with building codes allowing large seismic drifts are likely to keep leaving a wide wake of damage ranging from cracked partitions to building overturning. Following the earthquake sequence affecting southeast Turkey in 2023, a team led by Committee 133 of the American Concrete Institute surveyed nearly 250 reinforced concrete buildings in the area extending from Antakya to Malatya. Buildings ranging from 2 to 16 stories were surveyed to assess their damage and evaluate the robustness of their structures in relation to overall stiffness, as measured by the relative cross-sectional areas of structural walls and columns. The majority of the buildings were estimated to have been built in the past 10 years. Yet, the structures surveyed were observed to have amounts of structural walls and columns comparable with amounts reported after the Erzincan (1992), Duzce (1999), and Bingol (2003) Earthquakes in Turkey. These amounts are, on average, much smaller than the wall and column amounts used in Chile and Japan. Because of that lack of robustness and given the intensities of the motions reported from Antakya to Malatya (with 10 stations with peak ground velocity (PGV) of 100 cm/s or more), it is concluded that structures in this region experienced large drifts. Excessive drift (1) exposed a myriad of construction and detailing problems leading to severe structural damage and collapse, (2) induced overturning caused by p-delta for some buildings, and (3) caused widespread damage to brittle masonry partitions. The main lesson is simple: ductility is necessary but not sufficient. It is urgent that seismic drift limits are tightened in high-seismicity regions worldwide. © The Author(s) 2024.Article Citation - WoS: 61Citation - Scopus: 60Performance of Structures in İzmir After the Samos Island Earthquake(Springer, 2022) Dönmez, Cemalettin; Sucuoǧlu, H.; Binici, B.; Canbay, E.; Dönmez, C.; Ilki, A.; Ay, B.Ö.; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThe October 30, 2020 Earthquake caused unexpectedly significant damage in İzmir considering its distance to the city. This paper evaluates the recorded ground motions, summarizes the performance of structures affected from the earthquake with emphasis on the reasons of damage. A detailed damage assessment was carried out by the Earthquake Engineering Research Center of Middle East Technical University to compile data on the damage of RC and masonry buildings. It was observed that majority of the damage was concentrated in the Bayraklı district due to its peculiar soil properties where many 7–10 story mid-rise RC buildings suffered heavy damage and collapse. The level of amplified ground motions combined with deficiencies of apparently non-code compliant buildings exacerbated the damage. The main reasons of damage were mainly attributed to the presence of soft stories, lack of proper detailing, poor construction quality, presence of heavy overhangs, and hence significant lack of code-compliance in essence. The influence of infill walls on seismic performance of deficient and inadequate buildings was clearly seen in this earthquake. This paper also discusses seismic code requirements in effect and their influence on the observed building performance. The recorded ground motions were compared with the code spectra to evaluate the performance of the buildings. The code response spectra were found to be well above the recorded ground motion spectra at the sites where significant damage was observed. © 2021, The Author(s), under exclusive licence to Springer Nature B.V.Article Citation - WoS: 1Citation - Scopus: 1Fragility Analysis of Wide-Beam Infill-Joist Block Rc Frames(Gazi Üniversitesi, 2022) Dönmez, Cemalettin; Dönmez, Cemalettin; Erberik, Murat Altuğ; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyPurpose: The purpose of the presented study is to develop fragility curves for the wide-beam infill-joist block reinforced concrete structures. Theory and Methods: Nonlinear time history analyses are performed for the set of selected ground motions. The performance levels are identified through pushover analysis and fragility curves are produced for ground motion parameters. Results: Fragility curves obtained for the wide-beam RC frames presents a different characteristic than the curves obtained for the conventional frames. Conclusion: Results show that wide-beam RC frame buildings are seismically more vulnerable than the conventional deep beam RC frame buildings based on structural models with similar properties. The possible reason seems to be low lateral stiffness of wide-beam frames that causes large lateral drift demands and therefore severe damage at the wide-beam column connections.Article Citation - WoS: 61Citation - Scopus: 60Performance of Structures in Izmir After the Samos Island Earthquake(Springer, 2021) Yakut, Ahmet; Dönmez, Cemalettin; Sucuoğlu, Haluk; Binici, Barış; Canbay, Erdem; Dönmez, Cemalettin; İlki, Alper; Caner, Alp; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThe October 30, 2020 Earthquake caused unexpectedly significant damage in Izmir considering its distance to the city. This paper evaluates the recorded ground motions, summarizes the performance of structures affected from the earthquake with emphasis on the reasons of damage. A detailed damage assessment was carried out by the Earthquake Engineering Research Center of Middle East Technical University to compile data on the damage of RC and masonry buildings. It was observed that majority of the damage was concentrated in the Bayrakli district due to its peculiar soil properties where many 7-10 story mid-rise RC buildings suffered heavy damage and collapse. The level of amplified ground motions combined with deficiencies of apparently non-code compliant buildings exacerbated the damage. The main reasons of damage were mainly attributed to the presence of soft stories, lack of proper detailing, poor construction quality, presence of heavy overhangs, and hence significant lack of code-compliance in essence. The influence of infill walls on seismic performance of deficient and inadequate buildings was clearly seen in this earthquake. This paper also discusses seismic code requirements in effect and their influence on the observed building performance. The recorded ground motions were compared with the code spectra to evaluate the performance of the buildings. The code response spectra were found to be well above the recorded ground motion spectra at the sites where significant damage was observed.Article Citation - WoS: 7Citation - Scopus: 5A Study on Mitigation of Interstory Drift Concentrations in Reinforced Concrete Frames Under Earthquake Demands(Patron Editore S R L, 2020) Sönmez, Egemen; Dönmez, Cemalettin; Dönmez, Cemalettin; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologySite observations and analytical studies show that low-rise RC frames have larger interstory drift ratios at the lower stories under earthquake loading. It is obvious that due to the localization of drifts, these structures could reach their capacity limits earlier than a system with a well-distributed drift among its stories. This phenomenon is especially vital for frames with limited drift capacity and could cause them to fail below the specified design demands. The existing stock of seismically deficient RC frames in Turkey, and for that matter all over the world, are in this group. The presented study investigates the effects of a pre-organized stiffness distribution along the building height to mitigate the interstory drift concentrations. As a case study, the readily available infill walls were used for stiffness-modifying elements to obtain the organized stiffness distribution. Initially, the numerical model was calibrated and verified using the experimental results. Afterward, three planar frames were studied. These were a bare frame and two frames with infill walls. Nonlinear dynamic time-history and pushover analyses were performed to evaluate the seismic performance of the frames. The results indicate that the organized stiffness distribution could mitigate the interstory drift concentrations and provide a better distribution of interstory drift ratios along the height of the frames.