Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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  • Master Thesis
    Investigation of Community Resilience To Earthquake Hazards: the Case of Bayraklı, İzmir
    (01. Izmir Institute of Technology, 2024) Elburz, Zeynep; Güngör, Melisa; Elburz, Zeynep
    Doğal ve antropojenik kaynaklı tehlikelerin arttığı ve risk toplumuna dönüştüğümüz çağda, şehirler ve topluluklar öngörülemeyen yıkımlarla karşılaşmaktadır. Bu yıkımlar, özellikle deprem tehlikesi karşısında topluluk dirençliliğinin (CR) incelenmesine duyulan gerekliliğin altını çizmektedir. Topluluğun zorlukları öngörme, uyum sağlama ve zorluklardan kurtulma becerisine vurgu yapan topluluk dirençliliği kavramı güncel literatürün önemli paradigmalarından biri olarak öne çıkmaktadır. Çok boyutlu bir kavram olan topluluk dirençliliği sosyal, ekonomik, fiziksel, çevresel ve toplumsal sermaye boyutlarını değerlendiren kapsamlı bir yaklaşım sunmaktadır. Bu çalışma, İzmir, Bayraklı'da deprem tehlikelerine karşı topluluk dirençliliğini sosyal, ekonomik, fiziksel, çevresel ve topluluk sermayesi boyutları bağlamında incelemektedir. Beş boyutun ağırlıklı ve sonuç haritalarının oluşturulmasında nesnel bir Çok Kriterli Karar Verme Yöntemi olarak Entropi Ağırlıklandırma Yöntemi (EWM) kullanılmıştır. EWM analizinin sonuçları, deprem tehlikesine karşı topluluk dirençliliğini ölçmek için en önemli boyutun çevresel (0.3873) olduğunu, bunu topluluk sermayesi ve ekonomik (0.1973), sosyal (0.1298) ve fiziksel (0.0883) boyutların izlediğini ortaya koymuştur. Ayrıca, her mahalle beş boyutta farklı düzeylerde topluluk dirençliliği açıkları sergilemektedir. Sonuçlara göre Adalet, Bayraklı, Tepekule, Çay, Osmangazi, Manavkuyu, Mansuroğlu ve Cengizhan mahalleleri düşük ve orta düzeyde topluluk dirençliliğine sahiptir. Bu mahallelerdeki topluluk dirençliliği açıkları, zayıf zemin koşulları, düşük bağlılık, topluluk ağlarının zayıflığı, otoriteye duyulan düşük güven ve hazırlık, düşük eğitim oranları ve düşük ve orta gelir düzeyi gibi faktörlerle ilişkilidir. Bu bulgular, topluluk dirençliliğini artırmak ve dirençli şehirler oluşturmak için çevresel, toplumsal sermayesi ve ekonomik boyutlardaki eylemlere öncelik verilmesi gerektiğini vurgulamaktadır.
  • Master Thesis
    Assessment of Structural Damage in Adıyaman and Calibration of Rapid Visual Screening Methods After Kahramanmaraş Earthquake Sequence
    (01. Izmir Institute of Technology, 2024) Ekinci, Yusuf; Demir, Uğur
    KAHRAMANMARAŞ DEPREMİ SONRASINDA ADIYAMAN'DAKİ YAPISAL HASARIN DEĞERLENDİRİLMESİ VE HIZLI GÖRSEL TARAMA YÖNTEMLERİNİN KALİBRASYONU Depremler, Türkiye'nin coğrafi konumu nedeniyle kaçınılmaz bir gerçekliktir. Gelecekte yaşanabilecek depremlerde can ve mal kaybını önlemek ve hasarı en aza indirmek için gerekli önlemlerin alınması ve sürdürülebilir stratejilerin geliştirilmesi gereklidir. Ancak, kapsamlı değerlendirmeler için yeterli zaman ve mali kaynak olmaması, yapıların risk durumlarına göre sınıflandırılmasını ve en riskli yapıların tespit edilmesini sağlayan hızlı deprem performansı değerlendirme yöntemlerinin geliştirilmesini zorunlu kılmıştır. Adıyaman'da Kahramanmaraş depremlerinde hasar gören yapılar, deprem sonrası yapılan hasar tespit çalışmaları sonuçlarına göre değerlendirilmiş ve hasar nedenleri tartışılmıştır. Kent merkezinde yer alan 45.337 yapı, hasar dağılımları, yapım yılları, kat sayıları ve yapım teknikleri açısından incelenmiş; 477 yapı ise tez kapsamında detaylı olarak ele alınmıştır. Bu çalışmada Adıyaman'daki 477 yapı, çeşitli hızlı değerlendirme yöntemleriyle analiz edilmiştir. Gerekli veriler Çevre, Şehircilik ve İklim Değişikliği Bakanlığı veri tabanı, saha çalışmaları ve Google Earth Sokak Görüntüleri aracılığıyla toplanmıştır. Yapılar, FEMA P-154 (FEMA, 2015), Kanada Sismik Tarama Yöntemi (Rainer et al., 1992) ve Türkiye'ye özgü Hızlı Görsel Tarama Yöntemi (Sucuoğlu et al., 2007) kullanılarak kat sayısı, taşıyıcı sistem tipleri, yapım yılı ve yapısal düzensizlikler gibi parametreler açısından değerlendirilmiştir. Karşılaştırmalı analiz, bu yöntemlerin sismik performansı belirlemede sınırlı doğruluğa sahip olduğunu göstermiştir. Güvenilirliği artırmak amacıyla, her bir yönteme ait ceza puanları gerçek deprem verileri kullanılarak kalibre edilmiş ve tahmin performansı iyileştirilmiştir. Çalışma ayrıca, tasarım aşamasındaki kararların sonuçlarını vurgulamakta ve mimarların yapısal düzensizliklerden kaçınmaları için rehberlik sunmaktadır. Anahtar Kelimeler: 2023 Kahramanmaraş Depremleri, Yapısal Hasar, Yapısal Düzensizlikler, Hızlı Değerlendirme Metotları, Adıyaman
  • Master Thesis
    Vulnerability assessment within the context of resilience To earthquake hazards: a case study of Bayraklı, İzmi̇r
    (01. Izmir Institute of Technology, 2024) Aydın, Helin; Kurt, Deniz Gerçek
    Depremler, tüm doğal afetler arasında, Türkiye tarihinde en yıkıcı sonuçlara yol açmış olup, afet kaynaklı can kayıplarının çoğunluğu depremlerden kaynaklanmaktadır. Bayraklı, tarihi ve ekonomik öneminin yanı sıra, yüksek afet riski potansiyeline sahip ve deprem tehlikelerine karşı savunmasız yapı stokunun yoğun olduğu İzmir'in ilçelerinden biridir. Bu çalışma, ilçenin deprem tehlikelerine karşı kırılganlığı değerlendirmeyi amaçlamaktadır ve Bayraklı'nın tüm mahallelerini (24 mahalle) kapsayacak şekilde mahalle ölçeğinde uygulanmıştır. Çalışmada kırılganlık kriterlerini ölçmek ve deprem tehlikelerindeki önemlerini belirlemek için uzman görüşlerini değerlendirmek üzere Aanalitik Hiyerarşi Süreci yöntemi kullanılmıştır. Üç boyutu kapsayan kapsamlı bir kırılganlık değerlendirmesi yapılmıştır.: fiziksel kırılganlık, sosyal kırılganlık ve yapılı çevrenin kapasitesi. Uzman değerlendirmelerine dayanarak, kriterlerin deprem tehlikelerine karşı kırılganlık açısından göreceli önemi ortaya çıkarılmıştır. Kriter ağırlıklarına dayanarak, ArcGIS kullanılarak her ana boyut için kırılganlık haritaları oluşturulmuştur. Bu son aşamada sırasıyla Çay, Çiçek, Alpaslan, Tepekule Bayraklı ve Muhittin Erener, olmak üzere en kırılgan mahalleler belirlenmiştir. Bu araştırmanın bulguları, Bayraklı'nın deprem tehlikelerine karşı kırılganlığını azaltmayı amaçlayan kentsel planlama ve stratejik çabalar için değerli içgörüler sağlama potansiyeline sahiptir. Anahtar Kelimeler: Kırılganlık Değerlendirmesi, Afet Riski, Deprem Tehlikesi, Kapasite, Dayanıklılık, Analitik Hiyerarşi Süreci
  • Master Thesis
    Earthquake Risk Management in Spatial Planning: the Case of Bayrakli-İzmir
    (2023) Öztürk, Dilara; Akpınar, Figen
    Turkey has a rapid urbanization and expansion, especially since 1950s. Today, 93.4 percent of the population live in urban areas (TurkSTAT 2022). This is a threat for the country because disasters that cause great damage to human life, building stock and urban infrastructure affect urban areas more negatively. Consequences of earthquake disasters have been experienced before because most of the country consists of earthquake-prone regions defined as high risk. That is why, the issue of reducing earthquake risks in spatial planning processes is of great importance for the country. Disaster mitigation strategies, policies, actions in planning decision making and implementation processes are currently crucial and cannot be postponed. 30 October 2020 earthquake caused more than 117 deaths, collapse of numerous buildings and massive damage in Bayraklı district of Izmir. The extent of the damage show that once again, the city has a high earthquake risk however it is not adequately prepared for that risk. This study aims to provide an overview of risk management in spatial planning, as well as providing guidance for future spatial planning methodologies, from the perspective of Izmir-Bayraklı's previous planning initiatives. After evaluating the earthquake risk management in spatial planning generally, the case of Bayraklı will be analysed in detail. This will include an analysis of the previous plans' risk management strategies, an explanation of why such significant destruction took place despite the existence of a nation-wide strict legal framework and planning efforts, and a recommendation for a spatial planning policy that will ensure the sound-basis risk management in planning. The case study area includes Mansuroğlu, Manavkuyu and Adalet neighbourhoods located in Bayraklı district of İzmir province.
  • Master Thesis
    Response of Vertically Loaded Energy Piles Under Earthquake Excitation
    (2023) İnayet, Mehmet Göktuğ; İşbuğa, Volkan
    Pile foundations are deep foundation systems that are used to transfer loads from superstructure to soil by either resisting surface friction or reaching a deeper and stiffer soil layer when geotechnical properties of the soil site are not sufficient to carry the loads transferred from superstructure. Energy piles fulfill the same function along with the ground heat exchanging via heat pump systems, thus satisfying the energy demand of a building for heating-cooling operations. This feature of energy piles draws attention as an innovative system supplying a renewable energy resource. However, heat exchanging operations of energy piles cause temperature variations on pile and the surrounding soil which may cause additional load and deformations. Moreover, temperature variations may affect the elasticity modulus of soils and shear strength of cohesive soils. In this study, earthquake response of an axially energy loaded pile was investigated considering the heating effect under 2020 Izmir earthquake motion using finite element method and compared to the those of identical regular piles. We performed analyses with different soil types, geometric properties, and temperature magnitudes under steady-state heating. Based on the analysis results, heating effect on pile head stiffness with respect to geometric properties were obtained. Two important conclusions have been made; (i) the most critical effect on heating depends on mechanical loading condition of pile and thermal expansion coefficient of soil, (ii) geometric properties may affect the temperature distribution resulting in an unforeseen change in pile head stiffness.
  • Master Thesis
    A Case Study: Site-Specific Seismic Response Analysis for Base-Isolated Building in Düzce
    (01. Izmir Institute of Technology, 2020) Eren, Volkan Gökçe; Ecemiş Zeren, Nurhan
    Under seismic loads, soil-structure interaction, and its effect on performance of pavements is more important today. Turkey is located in one of the most active seismic zones in the world. In the past, many destructive earthquakes happened in Turkey. The fact is that due to frequent earthquakes in the future, we may suffer a significant loss of life and property. Therefore, it has been necessary to minimize demolitions by conducting soil behavior analysis for each site. To design buildings, bridges, and other structures with base-isolators according to performance, it is necessary to carefully evaluate the long-term ground motions, especially in determining the earthquake ground motion. In these evaluations, empirical and theoretical methods to predict the response spectrum, considering and analyzing the effects of the near-fault, scaling the spectrum for different damping ratios, and simulation of long-term ground motions time-history constitute an essential place. It is necessary to determine the principles required for modifying the design spectrum in the long-period boundaries. The regulations are required to simulate long-period ground motions in the time-history and the necessary rules for selecting and scaling the earthquake ground motion records by considering the long-period effect. In this thesis, commonly used approaches in national and international regulations in defining the earthquake effect were evaluated, and the recommended earthquake levels for structures within the Düzce city in Turkey are explained. While evaluating the earthquake hazard in the study area, the general geology, tectonic features, ground conditions, and existing fault systems of the region were considered. For the study area, besides the classical hazard spectra, hazard curves for different spectral ordinates that allow the calculation of probabilistic seismic hazard maps and spectral coordinates for various periods are presented. Earthquake records were selected according to these spectra, and nonlinear analyses were made by simulating earthquake data for structural analysis. Turkey Earthquake Building Regulations (TBDY, 2018) to determine the seismic design spectrum is considered.
  • Master Thesis
    Seismic Analysis of an Ancient Lighthouse by Meso-Scale Modeling Technique
    (01. Izmir Institute of Technology, 2020) Gözün, Safiyullah Üveys; Özdemir, İzzet; Dönmez, Cemalettin
    Modeling masonry structures has always been a difficult subject due to the lack of information about the behavior, the heterogeneity of the masonry materials and complex geometries of masonry structures. In terms of the computational costs and complexity, several methods are proposed in the literature. In this thesis, the capabilities of the meso-scale modeling technique are investigated by means of two experiments selected from the literature and the seismic response of an ancient lighthouse. Brick and mortar type structure is idealized as expanded units surrounded by zero thickness cohesive interfaces representing the mortar behavior. This means that the failure of mortar layers is considered explicitly by means of cohesive surfaces whereas the mechanical response of expanded units is described by Drucker-Prager/Cap model. This approach is used to simulate the in-plane and the outof-plane behavior of masonry walls reported in the literature. After validating the models with the experimental results, implicit-dynamic time history analyses of an ancient lighthouse are conducted by using 2 different earthquake records. The influence of mortar properties on the energy dissipation mechanisms and collapse pattern of the structure are investigated by means of a parametric study. As an attempt to identify the critical earthquake level corresponding to the initiation of sliding within the lighthouse, a set of additional analyses are conducted with scaled earthquake records.
  • Master Thesis
    Investigation of the Effect of Structural Grid Discontinuity on the Earthquake Behavior of Midrise Rc Moment Frames
    (Izmir Institute of Technology, 2019) Gemici Yormaz, Mefküre Banu; Dönmez, Cemallettin
    Reinforced concrete (RC) moment frames are the most common form among the building type structures in Turkey. The contemporary seismic design of building type structures evolves around the definition of deviations from an ideal structure that has a square-like floor plan, symmetric and uniform framing and mass distribution. These deviations are called the irregularities which are grouped in two as horizontal and vertical irregularities. There exists a horizontal irregularity that is not addressed in the current approach but it is needed to be investigated due to its possible impact on the lateral stiffness of the structure. It is the discontinuity of the horizontal grid in the structural frame. The purpose of this study is to investigate the earthquake response of the RC buildings that have horizontal grid discontinuities. It is intended to observe the level of additional vulnerability on the seismic response of RC moment frames due to this irregularity. Two 5-story reinforced concrete buildings are modeled in order to investigate the effects of the grid discontinuity phenomenon using nonlinear time-history analysis. The first building has discontinuous beams and framing that demonstrates the irregularity in the plan while the second one is the control case with uniform structural framing. The results are evaluated based on the member damage level. It is observed that the buildings with grid discontinuities are more vulnerable than those without irregularities to seismic excitation. Further study is needed to define a procedure to mitigate the vulnerability created by the horizontal grid discontinuity.
  • Master Thesis
    Effects of Consolidation Characteristics on Cpt Cone Resistance and Liquefaction Resistance in Silty Soils
    (Izmir Institute of Technology, 2013) Karaman, Mustafa; Ecemiş, Nurhan
    One of the most important reasons of the life and property losses caused by earthquakes is liquefaction during or after the earthquakes. Many researches focused on liquefaction after the earthquakes have revealed that liquefaction occurs mostly in silty soils. Empirical relationships between normalized cone penetration resistance (qc1N), cyclic resistance ratio (CRR), magnitude of earthquake (Mw), and silt content (FC), derived from field observations, are currently used for liquefaction potential assessment of loose saturated sands and silty sands. However, the effects of fine content on liquefaction resistance and penetration resistance are not defined clearly in these researches. For this reason, it is aimed to investigate the effects of fine content on consolidation characteristics and the effects of coefficient of consolidation on liquefaction resistance and cone penetration resistance. In this study, a number of field and laboratory studies were carried out to investigate the existing relationships. According to the results of experimental studies, first, the effects of the fines content on coefficient of consolidation and drainage characteristics of soils for different soil density ranges are examined and it is established that, both the fines content and the relative density effect the coefficient of consolidation of the sands and silty sands. Second, the changes in cone penetration resistance are investigated for different range of fines content and the relative density which have significant influence on coefficient of consolidation. It has been realized that the coefficient of consolidation indicates a significant influence on the measured penetration resistance during penetration of the CPT cone to the soil having different relative density, and it is figured out that for stiff-dense to medium dense soil, the decrease of normalized cone resistance is observed due to the change in drainage characteristics of fines or coefficient of consolidation. On the other hand, for loose soils only the relative density indicates a significant influence on the measured CPT penetration resistance around the probe. Finally, the contribution of the relative density on the liquefaction resistance of soils is observed at different fines content and compared with the available method in the literature.
  • Master Thesis
    Effect of Infill Wall Stiffness Variations on the Behavior of Reinforced Concrete Frames Under Earthquake Demands
    (Izmir Institute of Technology, 2013) Sönmez, Egemen; Dönmez, Cemalettin
    Reinforced concrete (RC) structures with infill walls are the most common building types in earthquake-prone regions of Turkey. Due to the complications in modeling the infill wall - frame interaction, they are generally neglected in structural design. However, presence of the infill walls has been proved to affect stiffness, strength and behavior of the structures significantly. Effects of infill walls may be either beneficial or detrimental under seismic demands. Infill walls typically increase the stiffness and strength of the structures. This situation may be advantageous for nonductile buildings up to a certain limit. However, brittle nature and variety of failure modes of infill walls may cause unforeseen and irreversible damages. Particularly, softstory mechanisms may occur due to drift concentrations at lower stories. An organized stiffness distribution along the height of the structure may help mitigating these negative effects. The main purpose of the study is to investigate the effects of stiffness variations in infill walls to the behavior of the frames. In order to achieve the purpose, an analytical software that supports an infill model, was selected. The software is calibrated and verified by simulating a series of experiments. Afterwards, a planar, fivestory, five-bay reinforced concrete frame was designed with common deficiencies observed in residential buildings in Turkey. The performance of the bare frame (BF) was determined using pushover analysis. Then, two types of infilled frames were obtained by introducing infill walls into two bays. The infill walls of the first infilled frame (IF-1) had a uniform stiffness and strength distribution along the height of the frame. In the second infilled frame (IF-2), the stiffness and strength of the infill walls had a decreasing profile from the bottom to the top story. By this distribution, drift concentration at the lower stories was aimed to be mitigated. Nonlinear dynamic and pushover analyses were performed on the frames. The results indicated that the organized stiffness distribution of IF-2 mitigated the drift concentrations and improved he seismic performance of the frame.