Civil Engineering / İnşaat Mühendisliği
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Article Citation - WoS: 61Citation - Scopus: 60Performance of Structures in İzmir After the Samos Island Earthquake(Springer, 2022) Yakut, A.; Sucuoǧlu, H.; Binici, B.; Canbay, E.; Dönmez, C.; Ilki, A.; Ay, B.Ö.The October 30, 2020 Earthquake caused unexpectedly significant damage in İzmir 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 Bayraklı 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. © 2021, The Author(s), under exclusive licence to Springer Nature B.V.Conference Object Citation - WoS: 2Evaluation of Streamflow Drought Index in Aegean Region, Turkey(Springer, 2022) Vaheddoost, Babak; Safari, Mir Jafar Sadegh; Gülmez, Ayşe; Mersin, DenizhanWater is an invaluable substance of which ensures the life cycle and hydrological events across the world. In this respect, water deficit also known as drought is a natural disaster related to water scarcity in time and space. Although there is no solid definition for the phenomenon, the outcome of repeated wet and dry spells cause in economic, social, and political problems at regional, country-wide, and world-wide scale. In this study, drought associated with the streamflow in the Aegean region, which has an important economic, historical and wsocio-cultural role in the western Turkey, is investigated through the well-known streamflow drought index (SDI). Therefore, average discharge in the Cicekli-Nif, Besdegirmenler-Dandalas, Bebekler-Rahmanlar and Kocarli-Koprubasi station respectively related to on Gediz, Buyuk Menderes and Kucuk Menderes basins were used. Then SDI with 1, 3, 6,12 months moving average are acquired to express the drought severity associated with the streamflow in the basins. Results showed that the SDI values in all of stations together with the 1, 3, 6, and 12-month moving averages depicts similar results and no abnormal situation exist during the study period.Article Citation - Scopus: 1Assessment and Transport of Sediment-Bound Estuarine Contaminants(Springer, 2015) Work, P. A.; Haas, K. A.; Warren, D. A.; Elçi, ŞebnemEstuaries and coastal bays frequently receive anthropogenically sourced contaminants. Many of these contaminants (e.g. most metals) have low solubility and tend to sorb to sediment particles, so that sediment transport driven by fluid mechanics becomes an important part of the contaminant transport problem. The chosen strategy for mitigation of the contaminant(s) will depend on the potential for migration away from the affected region, or the build-up of concentrations within the receiving area if loading rate exceeds decay or transport rates, and the potential impact on environmental and human health both within and outside the receiving area. Two case studies are considered here in which data describing instantaneous contaminant concentrations in estuarine environments were acquired via field sampling. Both sites feature estuaries dominated by tidal forcing, with smaller, adjacent upland regions also impacted. Metals, particularly copper and lead, are the primary focus in each case. Contaminant transport processes, including diffusion, advection, and bioturbation, are treated together to develop analytical and numerical solutions for time-dependent contaminant concentrations using a spatially varying, time-dependent, effective diffusion coefficient that is influenced by local surface water flow speeds. Different initial, boundary, and loading conditions are considered to illustrate the relative importance of the various transport processes. Implications of future contaminant loading and sea level rise scenarios are demonstrated and discussed.Book Part Suspended Sediment Concentration in Stratified Lakes Estimated by Acoustic Methods(Springer, 2012) Elçi, Şebnem[No abstract available]Article Citation - WoS: 9Citation - Scopus: 11Modeling of Pile-Soil Interaction in Laterally Loaded Pile Groups Embedded in Linear Elastic Soil Layers(Springer, 2020) İşbuğa, VolkanThis study proposes a new method to obtain the lateral response of pile groups by incorporating the pile group effect in layered soils. When a pile is loaded laterally, it creates a zone of influence in the direction of loading. In a pile group, each pile placed in the influence zone of prior piles is exposed to extra loads due to the load transfers from other piles. This mechanism results in a group effect which causes each pile in the group to have a different deflection curve compared to that of an identical isolated single pile under the same load. This study starts with a mathematical approach to model the interaction of two piles and then extends it to pile groups. The governing differential equation of a pile deflection problem is modified to take the pile-soil-pile interaction into account and solved analytically for each pile while the soil parameters and displacement fields around each pile are obtained numerically using the finite difference method written in Fortran language. The model captures the additional pile deflections induced by the group effects in pile groups and the results match well with the results of the existing methods, especially the finite element method.Article Citation - WoS: 2Citation - Scopus: 1Investigation of Groundwater Potential and Groundwater Pollution Risk Using the Multi-Criteria Method: a Case Study (the Alasehir Sub-Basin, Western Turkey)(Springer, 2020) Demirkesen, Ali Can; Budak, Seda; Şimşek, Celalettin; Baba, AlperDetermination of the groundwater potential (GWP) and groundwater pollution risk (GWPR) areas is a very important tool in the semi-arid regions in the world. Like many countries in the world, most of the major settlements in the cities of Turkey are located in permeable alluvial plains. Therefore, significant groundwater pollution is encountered in an alluvial plain containing settlements and industrial sites. This study focuses on the determination of the GWP and GWPR areas in the Alasehir sub-basin, which is one of the economically important districts of the Aegean region, located in the Gediz River basin in western Turkey. In this study, the GWP and the GWPR areas were identified and a GWP index map was generated. The GWP areas in the study basin were determined using different proxies as a multi-criteria method based on geographic information system (GIS) integrated with remote sensing (RS). The result of the study indicates that the most GWP locations in the basin are seen in the west and southeast of the study region. Based on these results, it is understood that the significant GWP and GWPR areas are near the big settlement districts such as Alasehir and Salihli. In particular, the 115-ha organized industrial zone located in the Salihli district is an important factor of the potential for consuming and contaminating water resources. This study method is so important for the selection of both city and industrial areas as well as for regional environmental planning in terms of the GWPR management.Book Part Citation - Scopus: 4Strain gradient crystal plasticity: Intergranularmicrostructure formation(Springer, 2019) Özdemir, İzzet; Yalçınkaya, TuncayThis chapter addresses the formation and evolution of inhomogeneous plastic deformation field between grains in polycrystalline metals by focusing on continuum scale modeling of dislocation-grain boundary interactions within a strain gradient crystal plasticity (SGCP) framework. Thermodynamically consistent extension of a particular strain gradient plasticity model, addressed previously (see also, e.g., Yalcinkaya et al, J Mech Phys Solids 59:1-17, 2011), is presented which incorporates the effect of grain boundaries on plastic slip evolution explicitly. Among various choices, a potential-type non-dissipative grain boundary description in terms of grain boundary Burgers tensor (see, e.g., Gurtin, J Mech Phys Solids 56:640-662, 2008) is preferred since this is the essential descriptor to capture both the misorientation and grain boundary orientation effects. A mixed finite element formulation is used to discretize the problem in which both displacements and plastic slips are considered as primary variables. For the treatment of grain boundaries within the solution algorithm, an interface element is formulated. The capabilities of the framework is demonstrated through 3D bicrystal and polycrystal examples, and potential extensions and currently pursued multi-scale modeling efforts are briefly discussed in the closure. © Springer Nature Switzerland AG 2019. All rights reserved.