Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2025Soil Amplification and Code Compliance: A Case Study of the 2023 Kahramanmaraş Earthquakes in Hayrullah Neighborhood
Avcı, Eyübhan; Afacan, Kamil Bekir; Deveci, Emre; Uysal, Melih; Altundaş, Suna; Balcı, Mehmet Can
In the earthquakes that occurred in the Pazarcık (Mw = 7.7) and Elbistan (Mw = 7.6) districts of Kahramanmaraş Province on 6 February 2023, many buildings collapsed in the Hayrullah neighborhood of the Onikişubat district. In this study, we investigated whether there was a soil amplification effect on the damage occurring in the Hayrullah neighborhood of the Onikişubat district of Kahramanmaraş Province. Firstly, borehole, SPT, MASW (multi-channel surface wave analysis), microtremor, electrical resistivity tomography (ERT), and vertical electrical sounding (VES) tests were carried out in the field to determine the engineering properties and behavior of soil. Laboratory tests were also conducted using samples obtained from bore holes and field tests. Then, an idealized soil profile was created using the laboratory and field test results, and site dynamic soil behavior analyses were performed on the extracted profile. According to The Turkish Building Code (TBC 2018), the earthquake level DD-2 design spectra of the project site were determined and the average design spectrum was created. Considering the seismicity of the project site and TBC (2018) criteria (according to site-specific faulting, distance, and average shear wave velocity), 11 earthquake ground motion sets were selected and harmonized with DD-2 spectra in short, medium, and long periods. Using scaled motions, the soil profile was excited with 22 different earthquake scenarios and the results were obtained for the equivalent and non-linear models. The analysis showed that the soft soil conditions in the area amplified ground shaking by up to 2.8 times, especially for longer periods (1.0–2.5 s). This level of amplification was consistent with the damage observed in mid- to high-rise buildings, highlighting the important role of local site effects in the structural losses seen during the Kahramanmaraş earthquakes.
- MakaleYalnız künye2025Evaluation of soil-structure resonance by determining local soil conditions in Gümüşhane city center
Altundaş, Suna; Tanış, Abdulsamed
Recent earthquakes have adversely affected human life, highlighting the necessity of identifying structural and ground conditions to assess risky areas and mitigate potential damage from future seismic events. Gümüşhane, the designated study area, is susceptible to the impacts of a possible earthquake due to its proximity to the North Anatolian Fault Zone (NAFZ). Accordingly, vertical electrical sounding (VES), multi-channel analysis of surface waves (MASW), and microtremor methods were employed in the central district of Gümüşhane to characterize local ground conditions and to evaluate the resonance hazard potential arising from the interaction between structures and the underlying soil. Dominant period (T0) and frequency (f0), spectral amplification (A0), soil index of vulnerability (Kg), average S wave velocity for 30 m depth (Vs30), ground type, and soil-structure resonance hazard potential were determined. For the study area, f0 values between 1.32–8.91 Hz (T0 values varied between 0.11–0.76 s), A0 values between 0.93–7.63 according to horizontal/vertical spectral ratio (HVSR) analysis, and Vs30 values were between 390–886 m/sec to MASW. As a result of the evaluation of microtremor measurements made in all buildings using the floor spectral ratio (FSR) technique, the soil-structure potential resonance hazard was found to be low. The present study, conducted in Gümüşhane, examined the subject of soil-structure interaction. In the process of planning new residential areas, it is imperative to ensure the reliability of construction based on the local ground conditions. Furthermore, it is essential to determine the risk status of buildings in relation to potential earthquake movements.
- MakaleAçık Erişim2023Uranium migration and radioactive characteristics of the Sarıçiçek and Sarıhan Granodiorites
Altundaş, Suna; Çınar, Hakan
The radionuclide concentrations of eU (ppm), eTh (ppm), K (%) and dose rate values were measured in Sarıçiçek (Gümüşhane) and Sarıhan (Bayburt) granodiorites for a duration of 5 minutes at each of 532 measurement points. The radioelement ratios (eU/eTh, eU/K, and eTh/K) indicating the origins of the rocks, the geochemical indicators (Ume, F parameter, and eU-(eTh/3,5) rate) showing the uranium mobility and the radioelement concentrations were calculated and mapped within the study areas. The average K, eU, and eTh concentrations were calculated as 2.98%, 3.15 ppm, and 12.45 ppm for Sarıçiçek granodiorite, and 1.83%, 2.73 ppm, and 13.6 ppm for Sarıhan granodiorite, respectively. Higher radioactivity values were observed in basaltic, sedimentary, and ultramafic rock combinations within the granodiorite masses. In the classification according to radioelement ratios, it was concluded that the rocks in the study areas formed as a mixture of upper mantle and crustal materials. In both study areas, there was uranium transport from the granodioritic masses into the surrounding rocks, and accordingly, the rocks in the surrounding formations were enriched in uranium. As a result, radioactivity levels, rock formation origins, and uranium transport of both granodioritic masses and rocks in the surrounding formations were determined by evaluation with radioelement concentration values and ratios and migration parameters. The study areas were characterized by associating them with geology in light of radioactive data.
- MakaleAçık Erişim2022Investigation of natural radionuclide variations and the possible uranium migration by testing with gamma-ray spectrometer: An example from Tuğlu Tepe and Deliler Sites in Şefaatli/Yozgat, Central Anatolia Region, Turkey
Altundaş, Suna
The in-situ gamma-ray spectrometry measurements are performed to define and map natural radionuclide variations and the possible uranium migration on the sandstone in the Central Anatolia Region and Deliler sites in Yozgat, Turkey. The concentrations of radionuclide (eU, eTh, K%) and dose rate values were measured totally on 384 points in both areas with a duration of 5 min at each measurement point. The radionuclide ratios (eTh/K, eU/K, and eU/eTh), geochemical indicators (Ume, F parameter and eU-(eTh/3,5) rate) of uranium remobilization in the rocks, and the hazard parameters were calculated and evaluated by using measured data. The separation of uranium-rich or poor areas was made easily and associated with lithological formations by evaluating all the maps produced together. While the highest concentrations of radionuclide, and dose rate values were recorded in the sandstone units under the cover layer that are Eocene neritic limestones, the lowest concentration values and dose rate were measured on siltstone and claystone in the northern part of the Tuğlu Tepe area. At the Deliler study area, the lower anomaly zones are coincide with the soils used for the cultivation of chickpeas consists of loosely cemented sandy clay siltstone, claystone, gravel, sand, silt, and clay whereas the highest concentrations observed in the outcropped sandstone and limestones. It can be seen that the study areas have variable radioactivity levels as a result of both the weathering from the surrounding granitic rocks and the transport and accumulation of sediments through different factors. On sandstones serving as reservoir rock for uranium mineralization in both Tuğlu Tepe and Deliler sites, there is a uranium migration from the granitic rocks towards these masses and sandstones have been enriched by uranium. As a result of the evaluations, it has been seen that the areas showing uranium enrichment originated from migration can be determined very easily by radioactivity measurements, which is a fast, economical and effective method.
- MakaleYalnız künye2017In situ gamma ray measurements for deciphering of radioactivity level in Sarıhan pluton area of northeastern Turkey
Çınar, Hakan; Altundaş, Suna; Çelik, Necati; Maden, Nafız
The present work utilizes in situ gamma ray spectrometric measurement data to map the surface geology of Sarıhan Granitoid and its surrounding area. The study area comprises three different lithological units, namely, Hozbirikyayla Formation (limestone and sandy limestones), Sarıhan Granitoid (consist of quartz monzodiorite, granodiorite and quartz diorite) and the Ophiolitic olistostromal melange (andesite, basalt, sandstone, gravelly sandstone). When lithological units are assessed according to the radioactivity characteristics, natural radionuclide contents (40K and radionuclides from 238U and 232Th series) of Hozbirikyayla limestones and ophiolitic melange rocks are lower than the Sarıhan pluton. The U, Th and K radionuclide contents were found to be 0.8–5.4 ppm, 10.1–33.6 ppm and 1.29–4.41% in the Sarıhan plutonic area and 0.9–5.3 ppm, 1.1–20.3 ppm and 0.04–2.71% in Horzbirikyayla formation, respectively. The element concentrations of 238U, 232Th and 40K of the Ophiolitic melange are 1.1–4.5 ppm, 1.6–25.3 ppm and 0.09–3.63%, respectively. Radioelement ratio maps are created for the studied area, because the parameters of radioelement ratios, eU/eTh, eU/K and eTh/K, reflect the radioactive characters of the rock and soil. The Hozbirikyayla Formation is characterized by the highest value of eU/eTh and lowest value of eTh/K. While the lowest eU/eTh and eU/K ratios were observed in the Sarıhan Granodiorite, the highest value of eU/K and eTh/K were obtained in the Ophiolitic olistostromal melange. By comparing these maps with the geology, it was found that the radioelement concentrations are in good agreement with the geological properties of the region. In addition to this, the radiation hazard parameters were evaluated to assess the radiation hazard for people living in this area. It has also been found that there is no significant radiologic hazard for humans and the environment in and around studied area.