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) 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.Article Citation - WoS: 1Citation - Scopus: 2Probabilistic Seismic Microzonation for Ground Shaking Intensity, a Case Study in Türkiye(Springer, 2023) Tönük, Gökçe; Ansal, AtillaThe purpose of seismic microzonation is to estimate earthquake characteristics on the ground surface based on a probabilistic approach to mitigate earthquake damage in the foreseeable future for the new buildings, as well as for the existing building stock. The probabilistic analysis and related results are very important from an engineering perspective since the nature of the problem can only be dealt with in a probabilistic manner. The uncertainties associated with these analyses may be large due to the uncertainties in source characteristics, soil profile, soil properties, and building inventory. At this stage, the probability distribution of the related earthquake parameters on the ground surface may be determined based on hazard-compatible input acceleration-time histories, site profiles, and dynamic soil properties. One option, the variability in earthquake source and path effects may be considered using a large number of acceleration records compatible with the site-dependent earthquake hazard. Likewise, large numbers of soil profiles may be used to account for the site-condition variability. The seismic microzonation methodology is proposed based on the probabilistic assessment of these factors involved in site response analysis. The second important issue in seismic microzonation procedure is the selection of microzonation parameters. The purpose being mitigation of structural damage, it is possible to adopt earthquake parameters like cumulative average velocity (CAV) or Housner intensity (HI) that was observed to have better correlation with building damage after earthquakes. A seismic microzonation procedure will be developed with respect to ground shaking intensity considering probabilistic values of the cumulative average velocity (CAV) or Housner intensity (HI).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 Deprem Yalıtımlı ve Geleneksel Binalarda Tesisatlar İçin Sismik Koruma Hesabı ve Gereksinimi(2023) Şadan, Bahadırİnşaat 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.Article Citation - WoS: 12Citation - Scopus: 13Damage Accumulation Modelling of Two Reinforced Concrete Buildings Under Seismic Sequences(Springer, 2023) 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.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) 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.