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Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2027/r/gumushane/14229
  A hierarchical metaheuristic framework for CPT-based soil liquefaction prediction with Kolmogorov–Arnold Network variants

  Günen, Mehmet Akif; Öztürk, Kaşif Furkan

  Soil liquefaction is a critical geotechnical hazard that threatens the safety of civil infrastructure under seismic loading, necessitating robust and interpretable prediction models. This study proposes a hierarchical framework for CPT-based soil liquefaction prediction using meta-heuristic-optimized Kolmogorov–Arnold Network (KAN) variants. The framework follows a two-stage optimization strategy. First, six state-of-the-art meta-heuristic algorithms are statistically compared to identify the most effective optimization method. Second, the selected algorithm is employed to optimize six KAN variants, including FastKAN, EfficientKAN, FourierKAN, ChebyKAN, JacobiRKAN, and PadéRKAN. Statistical comparisons based on the Wilcoxon signed-rank test demonstrate that the Colony-Based Search algorithm (CSA) achieves lower objective-function values than the competing meta-heuristics (p<0.01) and is therefore adopted as the core optimization strategy. Performance evaluation reveals that the CSA-optimized ChebyKAN model achieves the highest predictive accuracy, with an F1 Score of 0.8875 ± 0.011 and an AUC of 0.9115 ± 0.013. Pairwise McNemar tests detected no statistically significant difference in classification decisions for any evaluated model pair (p>0.01). SHapley Additive exPlanations analysis identified qc, qc1N, and amax as the variables with the largest model-specific attributions, whereas d, c, and σv received lower attributions. A cost-sensitive error analysis further showed that ChebyKAN produced the lowest false-negative rate and the lowest asymmetric error cost under 5:1 and 10:1 false-negative-to-false-positive cost scenarios, supporting its conservative behaviour for safety-critical liquefaction screening. The results establish the proposed CSA–KAN framework as a reliable, high-accuracy, and interpretable solution for CPT-based soil liquefaction assessment in geotechnical engineering practice.

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• MakaleYalnız künye2026/r/gumushane/13744
  Effects of earthquake frequency content and isolation thickness on seismic behavior of a structure system resting on geotechnical seismic isolation layer

  Ozturk, Kasif Furkan; Cakir, Tufan; Araz, Onur

  Geotechnical seismic isolation (GSI) systems aim to partially dissipate the energy before it reaches the foundation of the structure system and are therefore regarded as an important alternative to structural seismic isolation systems. In addition, the use of petroleum-derived waste materials in the GSI systems fills a significant gap in the field of waste recovery. The present study investigates the changes in the dynamic responses of a 5-story building system with and without GSI, using a set of earthquakes classified according to their frequency content. For this purpose, parametric analyses were performed using analytical methods, considering three different earthquake frequency contents and six different GSI thicknesses. Furthermore, an approach for selecting the GSI thickness was suggested. The results generally show that, for structures founded on both natural soil (NS) and GSI systems, the earthquakes with low frequency content produce responses greater than the average responses calculated for all the investigated earthquakes. Although increasing the GSI thickness has a significant effect on attenuating structural responses, increasing this thickness beyond 3 m does not lead to a relatively significant reduction in the dynamic responses of the investigated structural system. Therefore, considering the structural system, NS, rubber-soil mixtures and earthquakes examined in this study, selecting a GSI thickness in the range of 2–3 m (inclusive) may be regarded as a practical approach for mitigating the dynamic responses of the structure since further increments in thickness beyond this range provide only progressively limited improvements in structural responses. Consequently, this research may provide meaningful data for the development of vibration control strategies to improve seismic resilience of structures, and the results are expected to be useful for better understanding of the GSI applications.

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• BildiriYalnız künye2026/r/gumushane/13531
  Dynamic Analysis of a High-Rise Building Under Near-Fault and Far-Fault Loads Considering Soil-Structure Interaction

  Kaya, Dilek; Cakir, Tufan; Ozturk, Kasif Furkan

  Earthquakes that have occurred in our country and various countries around the world over the past 30 years have clearly indicated that the complex relationship between the soil, structure, and earthquake requires further research. This situation has shown that building behavior under dynamic loads can vary depending on parameters such as structural geometry, foundation soil system characteristics, and earthquake characteristics. Due to the fact that near-fault movements contain higher accelerations and higher velocity components compared to far-fault movements, high-rise structures may exhibit relatively more sensitive behavior under such loads and may be negatively affected by these earthquake contents. In this context, the aim of this study is to investigate the dynamic behavior of a 12-story building system under near-fault and far-fault ground motions, taking into account different soil properties. To this end, three-dimensional finite element models were first created for the 12-story building system, considering both fixed and flexible foundation conditions. Modal analyses were performed using finite element models created with ANSYS software, and the obtained mode periods were compared with those obtained from analytical models. Subsequently, the dynamic behavior of the 12-story building system was investigated using relative displacement, stress, and acceleration responses obtained from time-domain analyses conducted for different soil systems and fixed foundation conditions. Comparisons of the dynamic responses showed that the structural dynamic responses could be influenced not only by the soil-structure interaction system but also by nearby and distant fault earthquakes.

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• MakaleAçık Erişim2025/r/gumushane/19648
  Investigation of Response of Embedded Pipe in Two-Layered Soil Subjected to Near-Fault and Far-Fault Earthquakes

  Öztürk, Kaşif Furkan

  The behavior of pipelines during earthquakes depends on many factors such as fault movements, soil types, pipe material properties and connection details. On the other hand, damages in pipeline systems can also be seen due to relatively high peak ground acceleration values caused by wave propagation effects, or liquefaction, surface rupture that may be triggered by earthquakes. In this context, in the scope of the study, the effects of soil-structure interaction phenomenon as well as near-fault and far-fault earthquake effects on the behaviors of the pipe system have been investigated using the developed two-dimensional finite element model. Modal analyses of soil-pipe interaction system have been made for the different soil conditions and dominant mode frequencies of interaction system have been compared with dominant site frequencies obtained using a well-known approach. In addition, parametric analyses have been performed in the time domain using different soil systems and earthquake loadings. The changes in the behaviors of the pipe system have been comparatively examined for different soil conditions and earthquake loadings considered. The obtained results importantly draw attention to the fact that the responses of the pipe system may vary depending on the soil-pipe interaction, near-fault and far-fault earthquake loadings.

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• MakaleYayıncıda açık erişim2025/r/gumushane/14300
  Optimizing Visibility of Historical Structures Using Modified Weighted Differential Evolution: Insights from the Kromni Valley, Gümüşhane, Türkiye

  Günen, Mehmet Akif; Öztürk, Kaşif Furkan; Aliyazıcıoğlu, Şener

  It is very important for historical structures to see each other in order to reveal the historical and cultural identity of a region. Historical structures in the Kromni Valley of Gümüşhane, located near the Sümela Monastery, served as places of worship, communication, trade, and social activity centers during their period of active use. This study analyses the spatial relationships of 38 historic buildings, including churches, chapels and castles, whose 3D models are created by in-situ measurements and point clouds obtained by unmanned aerial vehicles, using a 3D viewshed analysis using geographic information systems and remote sensing data. The research introduces a modified weighted differential evolution-based viewshed analysis (mWDE-WS) to enhance the visibility of these structures. In order to assess the applicability of the proposed method, a statistical comparison was conducted between four different Differential Evolution (DE) algorithms (standard DE, LSHADE, CobiDE, JADE and WDE) and the mWDE. The Wilcoxon signed-rank test indicates that mWDE is a more effective solution than alternative methods for addressing the relevant real-world issues. The study also integrates drainage network analysis to assess flood risks and the relationship between cultural structures and water flow. Findings show that historical structures in the region were built not randomly but within a rational approach and 64% of the study area is visible from structures and 2% of the area is visible from ten or more structures. mWDE-WS analysis revealed that the visible area could increase by 20% to 84.37% if the historic structures were placed in optimal locations. In addition, the historical structures were built away from 3rd order streams to minimize flood risk and humidity, demonstrating the community's awareness of the local topography and hydrology.

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• MakaleAçık Erişim2025/r/gumushane/14168
  Supervised classification-based framework for rock mass discontinuity identification using point cloud data

  Günen, Mehmet Akif; Öztürk, Kaşif Furkan; Aliyazıcıoğlu, Şener

  Mapping and evaluating rock mass discontinuities using point clouds is a critical task in mining, civil, and geological engineering. Rock discontinuities can significantly impact the integrity, strength, and stability of rock masses. The orientation of these discontinuities is also a key characteristic of the rock mass. Accurate orientation estimation from point clouds enables more precise predictions of rock mass behavior, leading to improved safety, more efficient excavation processes, reduced operational costs, and significant time savings. In this context, a supervised classification-based framework is proposed for calculating orientation parameters from point cloud. Supervised classification plays a crucial role in tasks where a model learns complex patterns from labeled data to accurately predict previously unseen instances. The proposed method consists of eight-steps, including: data collection, pre-processing (data filtering), adaptive neighborhood size selection (omnivariance-based), feature extraction (geometric features), feature selection (Minimum Redundancy Maximum Relevance method), classification (Support Vector Machine), clustering (connected component labeling), and plane fitting to calculate orientation parameters (dip angle and dip direction). The framework was applied to two real-world datasets and one synthetic dataset, which was tested in two different subsampled forms (random and uniform subsampling). The results statistically demonstrated that the technique was effective in detecting and characterizing rock mass discontinuities with high Accuracy, Recall, Precision, and F-Score values ranging from 94.64% to 99.57%. The deviations of the method in the measurements of the dip angle and the dip direction, compared to the manual measurements, range from 1% to 4%, indicating strong agreement with the manual measurements and the existing studies.

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• MakaleAçık Erişim2025/r/gumushane/14114
  Investigation of the effects of mainshock-aftershock sequences on the dynamic responses of pipeline considering soil-pipeline interaction

  Ozturk, Kasif Furkan

  Pipelines are important structural elements that are frequently used today to meet many infrastructures needs such as drainage, natural gas or water transmission. In this context, the usability of such structures, which are important elements of infrastructure systems, especially after disasters such as earthquakes, is of great importance. For this reason, within the scope of this study, a parametric investigation of the seismic behaviors of a natural gas pipeline system under mainshock-aftershock sequences have been carried out, specifically taking into account the soil-natural gas pipeline interaction (SNGPI) in the help of finite element model (FEM) proposed. Before developing the model of SNGPI system proposed using solid element, the fundamental mode frequencies of the pipeline system modeled using the solid element for the verification have been compared with those of obtained from the pipeline system modeled using the beam element and the analytical solutions. After verification of proposed model is demonstrated, SNGPI system has been modeled and its fundamental modes have been compared with mode frequencies of soil stratum obtained from well-known simple analytic solutions. After this stage, the dynamic analyses of natural gas pipeline (NGP) system in the time domain have been carried out using four different soil systems and four different mainshock-aftershock sequences. The results of the nonlinear time-history analyses have been investigated in terms of the stress and the displacement responses. Parametric evaluations show that the greatest displacements and the stresses occurring at the considered nodes of NGP system may be importantly affected from mainshock-aftershock sequences and soil stiffness changes. As the soil stiffness decreases, both the peak stresses and displacements increased significantly. On the other hand, the same responses obtained under mainshock loadings, which have relatively lower peak ground acceleration (PGA)/peak ground velocity (PGV) ratio compared to aftershock loadings, are generally larger than those obtained under aftershock loadings.

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• MakaleYalnız künye2025/r/gumushane/11755
  Assessment of Seismic Responses of Square-Hollow-Section Joints in a Lattice Girder with Soil-Structure Interaction

  Ozturk, Kasif Furkan; Ozyurt, Emre; Araz, Onur; Cakir, Tufan

  The fixed base approach is widely used to obtain the seismic behaviour of Square Hollow Section (SHS) joints in a lattice girder. However, in some cases where soil-structure interaction (SSI) can be relatively significant, this approach may result in incorrect acquisition of the natural periods and dynamic responses of the lattice girders using welded tubular joints. This situation may negatively affect the safety of the structure by causing an underestimation of the dynamic loads acting on the structure. Therefore, this study evaluates the seismic behaviour of SHS joints in a typical lattice girder exposed to different ground motions considering SSI. A nonlinear finite element analysis software, Abaqus, performs the dynamic analyses considering six earthquake excitations with three different frequency contents (a ratio of peak ground acceleration (PGA) to peak ground velocity (PGV)) and four different soil types. After verifying the numerical model, it is determined that 3D solid elements should be used to capture the actual seismic behaviour of the tubular joints in a steel truss frame with or without SSI. A comprehensive parametric study is then carried out to evaluate the peak displacement and stress values on the SHS joints with and without SSI under different ground motions with different PGA/PGV ratios. The findings show that the stresses are concentrated around the column and bottom chord connection region. Besides, the SSI mechanism significantly affects the peak stress and displacement values of the SHS joints, especially in soft soil types. Furthermore, it is observed that the PGA/PGV ratio significantly changes the seismic responses of the steel truss frame.

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• MakaleYalnız künye2025/r/gumushane/11720
  Effect of frequency content of ground motion on seismic response of buildings with variable aspect ratio including soil-structure interaction

  Kaya, Dilek; Cakir, Tufan; Ozturk, Kasif Furkan; Araz, Onur

  Soil-structure interaction (SSI) may lead to reduction, amplification or negligible change in structural responses depending on the relationship between the nature of excitations and subsoil conditions. Since neglecting SSI effects may cause uncertainties in seismic design, it is crucial to consider them during the design process. Another important factor affecting the dynamic behavior of structures interacting with the ground is the dynamic properties of the structures. To consider this effect, three buildings with 4, 8, and 12 stories designed in accordance with the Turkish Building Earthquake Code (TBEC-2018) are analyzed. The aspect ratios of these structures are 2, 4, and 6, corresponding to squat, ordinary, and slender structures, respectively. The primary objective of this study is to simulate the combined effects of these key parameters on the dynamic response of reinforced concrete structures. In the time history analyses, six ground motions classified by three different frequency contents are considered. 3D finite element models of SSI systems are established using ANSYS software. The usability of the numerical models is demonstrated for both SSI and fixed-base cases through three different analytical approaches. The displacement, acceleration, and stress responses are examined through time history analyses. The results indicate that the SSI is not negligible and neglecting the SSI is an oversimplification that does not lead to always-conservative predictions. Moreover, both the frequency content of the excitation and the structural aspect ratio are found to be decisive parameters in seismic response.

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• MakaleAçık Erişim2025/r/gumushane/11706
  Investigation of the Dynamic Behavior of Buried Natural Gas Pipe System

  Öztürk, Kaşif Furkan

  Natural gas pipelines are important infrastructure elements that are often designed to be buried and can cross very long distances, both on the mainland and on the ocean seabed. In this context, researches on the safety of these structures, which are known to cause significant economic losses if damaged, still maintains its importance. From this point of view, the dynamic behavior of a buried pipe system modeled using the equivalent spring-dashpot approach is investigated for three different soil systems and two earthquake records with three different frequency contents. The research shows that while the peak von mises stress of the pipe system can generally decrease depending on decrease in soil stiffness, the peak lateral displacements of the pipe system can generally increase depending on the decrease in soil stiffness. Furthermore, the results point out that the peak von mises stresses and the lateral displacements of the pipe system can significantly increase from high frequency content to low frequency content depending on the frequency content of earthquake.

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