Welcome to the Polen - ITU Academic Archive

Polen stores all academic resources—such as books, articles, theses, papers, reports, and research data—directly or indirectly published by the academic and administrative staff and students of Istanbul Technical University in a digital environment in accordance with international standards. It facilitates monitoring the university’s academic performance, ensures the long-term preservation of resources, and provides open access to publications in compliance with copyright regulations to enhance their impact.

The ITU Open Access System provides access to scientific and artistic works—such as books, articles, theses, encyclopedias, and artworks—produced by our faculty members and students in accordance with international standards and intellectual property rights.

Supported by @SelenSoft Yazılım

Articles

Books

Book Parts

Master Theses

Doctoral Theses

Communities in DSpace

Select a community to browse its collections.

Now showing 1 - 5 of 6

Açık Ders Kaynakları 30
İTÜ'de verilen bazı derslerin video kayıtlarını içermektedir.
Akademik Çalışmalar 45345
İTÜ'de yapılan akademik çalışmaları içermektedir.
Arşiv Koleksiyonu 603
Çeşitli birimlerde yer alan arşiv koleksiyonunu içermektedir.
Sunumlar 42
Kurum içinde yapılan çeşitli sunumların çıktılarını içermektedir.
Temel Kayıtlar 2825
Master Data

Recent Submissions

Access status: Metadata only ,
Assessing Post-Seismic Hillslope Stability with Finite Element Methods
(Copernicus GmbH, 2025-03-18) Yu Wang; Luigi Lombardo; Cees J. van Westen; Tolga Gorum; Abdüssamet Yılmaz; Hakan Tanyaş; Avrasya Yer Bilimleri Enstitüsü; Görüm, Tolga; Yılmaz, Abdüssamet
Earthquakes can induce a legacy effect on hillslopes by reducing rock mass shear strength through fracture development and cohesion loss, thereby increasing landslide susceptibility. While methods for modeling shear strength reduction exist, post-seismic landslide susceptibility assessments that account for this earthquake legacy effect remain unexplored. In this study, we address this gap by performing regional-scale slope stability analyses using Finite Element Methods (FEM). Focusing on the area affected by the 2023 T #252;rkiye earthquake, we conduct back-analyses to estimate the shear modulus of hillslopes that failed during the event. Using an empirical relationship for shear strength reduction, we estimate post-seismic shear strength and integrate these parameters into FEM simulations to evaluate hillslope deformation. The deformation results are subsequently used to assess landslide susceptibility across the region.This study represents the first application of FEM for regional-scale landslide susceptibility analysis, systematically accounting for changes in rock mass strength due to seismic events. The proposed framework enhances the accuracy and reliability of post-seismic slope stability assessments, providing a step forward in regional-scale, post-seismic landslide hazard evaluation.
Access status: Metadata only ,
Reliability-Based Analysis of Initiation of Sediment Motion on Movable Bed
(Copernicus GmbH, 2025-03-18) Selman Baysal; V. Ş. Özgür Kırca; Manousos Valyrakis; İnşaat Mühendisliği Bölümü; Kırca, Veysel Şadan Özgür; Baysal, Selman
Sediment transport dynamics are of great importance in understanding geophysical flows, where determining the threshold conditions for the initiation of sediment motion presents a complex challenge. In a pioneering work, Shields (1936) established the Shields #8217; criterion to assess the critical shear stress ( #964;c) required for sediment motion in non-turbulent flows. Although this approach has significant advantages, including a robust empirical foundation and the implementation of non-dimensional critical shear stress, it is valid for limited conditions since it oversimplifies vital aspects such as sediment heterogeneity and complex flow interactions.In turbulent flows, the effective critical shear stress acting on a grain may become higher than that measured in the case of laminar flows (i.e., the average critical stress, #964;c, defined by Shields, 1936) as a result of fluctuations in the shear stress ( #964; #8242;). Owing to this, in geophysical turbulent flows near the threshold of motion, neither the driving nor the resisting parameters of sediment motion have crisp values; instead, they may be considered probabilistic parameters. The reliability-based approach is applied here in to handle the complex nature of the initiation of sediment motion.This study aims to present preliminary results of research that aims to enhance the knowledge of incipient motion by applying a reliability-based analysis of Shields #8217; criterion based on the theory and empirical equations adopted by Zanke (2003). In this analysis, the turbulence parameter (n) and angle of repose ( #981;) are introduced as key parameters regarding the initiation of sediment motion. These parameters are generated as random variables by means of Monte Carlo Simulations, introducing various probabilistic distributions (e.g., normal, log-normal, triangular, gamma) and statistical moments (e.g., mean, standard deviation).By simulating a wide range of angles of repose and turbulence parameters with Monte Carlo Simulations, the inherent uncertainties in sediment transport and the complexity of hydrodynamic models are incorporated. In this work critical shear stresses of thousands of grains are assessed for different grain Reynolds numbers. As a result, threshold of motion curves are probabilistically derived, indicating confidence for grain entrainment, and establishing a model that enables risk assessment and decision-making for a wide range of scenarios. Comparisons of model results with empirical data show that the model captures the complex physical process.
Access status: Metadata only ,
Multistage lithospheric drips control active basin formation in the Central Anatolian Plateau: insights from analogue and numerical modelling
(Copernicus GmbH, 2025-03-18) Julia Andersen; Russell Pysklywec; Oğuz Göğüş; Ebru Şengül Uluocak; Tasca Santimano; Avrasya Yer Bilimleri Enstitüsü; Göğüş, Oğuz Hakan
Geological and geophysical studies suggest that plateau uplift in regions such as Tibet, Colorado, the Andes, and Anatolia may be in part related to #8216;lithospheric dripping #8217;; a process whereby dense lithosphere is removed as a viscous instability. Recent satellite-based measurements and crustal isostasy studies, reveal an interesting tectonic puzzle at the Central Anatolian Plateau in Turkiye since the data indicate rapid subsidence of the Konya Basin within the overall uplifted plateau. Here, we combine results from 3D analogue/laboratory experiments and 2D numerical models with quantitative analyses to study lithospheric drip processes which may be responsible for this local basin subsidence within the plateau. 3D analogue models were built in the laboratory using materials such as polydimethylsiloxane (PDMS), clay, and sand to model lithospheric drip instabilities. Image correlation techniques such as Particle Image Velocimetry (PIV) and digital photogrammetry were used to monitor material flow and changes in topography of the analogue model. In conjunction, similar 2D numerical models were developed using viscoplastic rheologies with the ASPECT geodynamics code. In reconciling the models with the observations, we interpret that the Konya Basin is subsiding due to a secondary localized lithospheric dripping event following a larger scale primary dripping event that was responsible for the broad uplift of the Central Anatolian Plateau. Furthermore, the numerical and analogue experiments suggest that the local secondary drip is `asymptomatic #8217;, in that it drives subsidence but no appreciable tectonic deformation (shortening or extension) of the crust. The findings indicate that multistage lithospheric foundering may be characteristic of the episodic development of orogenic systems.
Access status: Metadata only ,
Increased motion of a slow-moving landslide following 2023 Kahramanmaraş Earthquake Doublet: Insights from Meydandere (Siirt) Landslide Complex, Türkiye
(Copernicus GmbH, 2025-03-18) Tolga Gorum; Suat Coskun; Abdullah Akbas; Caglar Bayık; Saygın Abdikan; Fusun Balik Sanli; Hakan Tanyas; Avrasya Yer Bilimleri Enstitüsü; Avrasya Yer Bilimleri Enstitüsü; Akbaş, Abdullah; Görüm, Tolga
Slow-moving (5x10-5 (mm/s)), deep-seated ( 5 m) landslides exhibit persistent but non-uniform motion at low velocities, and deformation rates can increase abruptly with a triggering factor such as earthquakes. #160;Although it is generally reported that such landslides become reactive in areas close to earthquake epicenters depending on the attenuation relations, the Meydandere (Siirt) landslide is approximately 560 km away from the February 06, Kahramanmara #351; earthquake epicenters, and due to the increased movement on the hillslopes a couple of days after the earthquake, local people reported the incident to the local authorities. Meydandere paleo landslide complex contains many secondary landslides and is developed in the Paleocene #8211;Early Eocene sedimentary rocks. Here, we utilize four years of Interferometric Synthetic Aperture Radar, accumulated precipitation, and volumetric soil water layer data to explore a slow-moving landslide's kinematics and causal linkage with far-field seismic effects. Based on the InSAR results, we have determined that the deformation rate of different secondary landslide bodies in the main landslide complex is slow but continuous with time, yet this rate has doubled after the earthquakes. We have revealed that cumulative precipitation and volumetric soil water layer changes may also play a profound role in this rate. On the other hand, we have statistically shown that the February 6, 2023, earthquake doublet has a primary control on landslide acceleration because there is no significant increasing trend in the velocities, although the peak values of precipitation-induced changes were higher in the previous period. We conclude that understanding the earthquake response not only of co-seismic landslides in earthquake-affected areas but also of existing large bedrock landslides in far-field areas relative to the earthquake epicenter will provide a comprehensive understanding of the hazard chain of large earthquakes.
Access status: Metadata only ,
Earthquake Damage Assessment Using SAR Imagery, Structural Data, and Geospatial Parameters
(Copernicus GmbH, 2025-03-18) Yusuf Gedik; Orkan Özcan; Mihrimah Özmen; Okan Özcan; Avrasya Yer Bilimleri Enstitüsü; Avrasya Yer Bilimleri Enstitüsü; Gedik, Yusuf; Özcan, Orkan
Earthquakes inflict extensive damage on urban settlements, posing significant risks to human life and infrastructure. This study investigates the destruction caused by the Mw=6.7 Sivrice earthquake, which struck on January 24, 2020. It focuses on its impact within the city center via remote sensing (RS) and geographic information system (GIS) methodologies for damage assessment. In the study, post-earthquake building damage data and building inventory, collected through field surveys and provided by the Ministry, were compared with the collapsed areas which were identified using Sentinel-2 optical imagery. The surface velocity rates of the study area over the past five years have been derived using advanced InSAR techniques, specifically Persistent Scatterer (PS) and Small Baseline Subset (SBAS) methods. Moreover, a comprehensive analysis of factors influencing building damage was conducted by integrating geological maps, active fault maps, Coulomb stress distribution, Vs30 velocities, and surface velocity rates in the city center with the building inventory. It was revealed that the damage estimation map produced by analyzing pre-earthquake data and the damage map produced by field studies carried out after the earthquake showed a similar pattern. The findings demonstrate that buildings constructed on alluvial soils having low Vs30 velocities with high surface velocity rates experienced the most severe damage. This analysis highlights critical geological and structural parameters that exacerbate earthquake-induced structural damage, offering valuable insights for urban planning and seismic risk mitigation.