Civil Engineering / İnşaat Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/13
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Conference Object Citation - Scopus: 2A Critical Evaluation of Proxy Measures Used To Quantify Excavation-Induced Damage in Masonry Buildings(CRC Press, 2022) Liu, Yiyan; Gülen, Burcu; Açıkgöz, Sinan; Burd, Harvey; Gilson, Ben; İlki, Alper; Dalgıç, Korhan DenizBuilding response during nearby excavation activities (e.g., tunnelling or deep excavations) is traditionally monitored by conducting displacement measurements. These displacement data are then post-processed to determine proxy measures that are correlated to damage categories. For masonry buildings, commonly-used proxy measures include building deflection ratio, horizontal relative displacement and angular distortion; simple mechanical models and empirical rules are used to define limiting values for these proxy measures to identify and control the level of cracking in buildings during construction. This procedure has a profound influence on mitigation and construction activities, and a critical evaluation of its veracity is needed. To this end, results from a recent experimental campaign on the settlement response of half-scale masonry buildings are examined in this paper. During these tests, detailed optical measurements were conducted, allowing the calculation of absolute displacements across the façade, as well as crack opening displacements at specific locations. These measurements facilitate a direct comparison between the actual observed damage and the damage category that is indicated by the proxy measures. The comparisons highlight the limitations of existing techniques. A discussion is provided on how proxy measure calculations can be improved to deliver more reliable indications of building damage. © 2022 the Author(s).Article Citation - WoS: 8Citation - Scopus: 13Masonry Buildings Subjected To Settlements: Half-Scale Testing, Detailed Measurements, and Insights Into Behaviour(Elsevier, 2023) Dalgıç, Korhan Deniz; Gülen, Burcu; Liu, Yiyan; Açıkgöz, Sinan; Burd, Harvey; Maraşlı, Muhammed; İlki, AlperIndustry procedures to assess the risk of settlement-induced damage to masonry buildings ignore key aspects of the problem, such as the influences of building weight, façade openings, and floor structures. Experimental data are needed to characterise the influence of these aspects on damage. This paper describes tests on three brick masonry half-scale building models subjected to settlements. The use of scaling rules in choosing the model materials and kentledge, the settlement apparatus, and the cross-validation of displacement and strain measurements are presented. Comparative evaluation of building responses show that: (i) the distribution of building weight and the resulting in-situ stresses play a key role in determining compliance to settlements, (ii) openings make the structure vulnerable to cracking and (iii) floor slabs stiffen and strengthen the building and prevent the formation of damage in the upper floors, leading to a concentration of damage at the ground storey.Article Citation - WoS: 61Citation - Scopus: 60Performance of Structures in Izmir After the Samos Island Earthquake(Springer, 2021) Yakut, Ahmet; Sucuoğlu, Haluk; Binici, Barış; Canbay, Erdem; Dönmez, Cemalettin; İlki, Alper; Caner, AlpThe 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: 9Citation - Scopus: 10Cyclic Compressive Behavior of Hybrid Frp-Confined Concrete(American Society of Civil Engineers, 2021) İspir, Medine; Dalgıç, Korhan Deniz; İlki, AlperThe aim of this study is to define the cyclic axial behavior of hybrid FRP (fiber reinforced polymer)-confined concrete based on the results of an experimental study presented here. Two different types of fiber sheets with different ultimate tensile strain capacities were used together in a suitable epoxy resin matrix to confine concrete. The inner and outer jackets of the concrete confinement were constituted with carbon (or glass) sheets with a relatively low tensile strain capacity and polyethylene terephthalate (PET) sheets with a high tensile strain capacity. PET fibers, which are a relatively new type of fiber, are made from recycled plastics. By varying the number of layers of the outer fiber sheet, different combinations were formed for the hybrid jackets. To characterize the cyclic axial behavior of hybrid FRP-confined concrete, experimental data were utilized to obtain the axial stress-strain relationship and dilation behavior. Based on the results, a stress-strain model for the envelope curve of the cyclic response of hybrid FRP-confined concrete is proposed.