Yenişehir (Bursa) yerleşim bölgesi için jeoteknik mikrobölgeleme modelinin oluşturulması.

The purpose of this study is to develop a geotechnical microzonation model regarding the suitability of the residential areas in Yenişehir (Bursa, Turkey), which is a currently developing settlement area in a seismically active region. For this purpose, soil properties and dynamic soil behaviors of the study area were assessed. Soil classification, soil amplification, natural soil predominant period, resonance phenomena and liquefaction potential of the study area were evaluated using borehole data and microtremor measurements. The raw data obtained from the previous studies carried out at Yenişehir were used for these assessments. The liquefaction potential for the study area was evaluated both in two-dimensional planimetric and three-dimensional volumetric assessments. Two geotechnical microzonation maps were produced for the study area according to the surface damage due to liquefaction (according to two different methods), soil amplification and distance to streams maps; by using Geographical Information Systems (GIS) based Multi-Criteria Decision Analysis. The weight values were assigned to the layers using Analytical Hierarchical Process method by pairwise comparisons. Evaluating geotechnical microzonation maps produced, the safest areas were found on the northern sites of the study area. The most critical areas were found to be in the middle and the southeast parts of the study area.Ph.D. - Doctoral Progra

Eskişehir yerleşim merkezi için coğrafi bilgi sistemleri tabanlı mikrobölgeleme haritası.

The purpose of this study is to prepare a geotechnical microzonation map regarding the suitability of the residential areas in Eskisehir downtown area. In order to obtain the microzonation map, Geographical Information Systems (GIS) based Multicriteria Decision Analysis (MCDA) is used. For this analysis, the slope, flood susceptibility, soil, depth to groundwater table, swelling potential and liquefaction potential layers are prepared. The weight values to the layers and rank values to the classes of each layer are assigned by applying Simple Additive Weighting (SAW) and Analytical Hierarchical Process (AHP) methods. Two geotechnical microzonation maps are obtained as outputs of these methods. The study area is categorized into three different zones regarding the foundation suitability of residential areas as: (1) Areas suitable for settlement; (2) Provisional settlement areas; (3) Areas requiring detailed geotechnical investigations. The maps prepared using SAW and AHP methods are found to be consistent with each other. The geotechnical microzonation map prepared using AHP method is recommended as the final map of the study area.M.S. - Master of Scienc

Assessment of degradation and stability of a cut slope in limestone, Ankara-Turkey

Due to the rapidly growing population of the city of Ankara (Turkey) and increased traffic congestion, it becomes necessary to widen the Ankara-Eskisehir (E-90) highway, connecting the newly built areas west of the city to the city center. During widening, several cut slopes were formed along the highway route. As a result, some instability problems (small-sized rock falls/sliding, sloughing, raveling) produced detachment zones along a cut slope in highly jointed, folded and sheared limestone, causing local degradation of the cut slope. Identification of the areas that are likely to detach from the cut slope in the future is considered to be very important for the application of remedial measures. For this purpose, the relationships between the existing detachment zones and various parameters (e.g. point load strength index, weathering, block size, daylighting, shear zone) were investigated using GIS-based statistical detachment susceptibility analyses in order to predict the further aerial extension of the detachment zones with time. During the overlay analyses, statistical index and weighting factor methods were used. Limit equilibrium analyses were also carried out for the determination of the possible large scale mass failures. The detachment susceptibility map using W-i method without the block size layer gives the best result and indicates some hazardous zones where detachments are likely to occur in the future. On the other hand, the limit equilibrium analysis of the rock mass using Bishop simplified method shows that except one section no mass failure is expected in the cut slope. Suitable remediation measures which include the use of wire mesh, shotcrete, toe support, and concrete barrier blocks or catch/barrier fences are recommended for these zones

A new approach to estimate cover-management factor of RUSLE and validation of RUSLE model in the watershed of Kartalkaya Dam

RUSLE is one of the most widely used soil erosion model worldwide. However, some of the input parameters of RUSLE may require extensive field and laboratory studies, and therefore in most of the cases these parameters are estimated according to some alternative approaches. In this context, cover-management factor (C) has significant importance since it is the most influential factor due to its effect on result, besides; there are some doubts about the alternative approaches which are used to estimate the C factor. Moreover, although plenty of RUSLE applications in different areas are conducted in Turkey, any comprehensive study regarding the validation of obtained RUSLE results according to specific conditions is lacking. In this study, the drainage basin of the reservoir of Kartalkaya Dam which is in the south eastern part of Turkey was chosen as the study area, and the average annual eroded material was identified though RUSLE. For the mentioned reservoir area, the availability of bathymetry measurements for 30 years time span between 1975-2005, provide the appropriate conditions to validate the results of the model since the deposited sediment volume could be quantified. Therefore, after the identification of the average annual eroded material for the sub-basins, SEDD model was applied in order to reveal the annual transported sediment amount within each sub-basin of the study area. The results obtained from the SEDD model were compared with the bathymetry measurements of the reservoir. In this context, the first objective of this study is to propose a new approach to estimate the C factor by using remote sensing and GIS techniques with previous studies based on experimental studies conducted on field. The second objective of the study is to estimate RUSLE parameters by using available datasets and to examine the applicability of the method on other basins in Turkey with same datasets. The third objective of the study is to estimate the transported sediment amount by using SEDD model, and by comparing its result with the bathymetry measurements of the reservoir to make a validation of both RUSLE and SEDD models

Development of geotechnical microzonation model for Yenisehir (Bursa, Turkey) located at a seismically active region

Earthquake hazard zonation for urban areas, mostly referred to as seismic microzonation, is the first and important step towards a seismic risk analysis and mitigation strategy in populated regions. Proper understanding of the local subsurface ground conditions is essential for a realistic assessment. Turkey is one of the earthquake prone countries in the World and the lessons particularly drawn from the devastating 17 August 1999 and 12 November 1999 earthquakes of Turkey revealed the importance of microzonation studies. The purpose of this study is to further develop a geotechnical microzonation model regarding the suitability of the residential areas in Yenisehir (Bursa), a rapidly developing settlement area in a seismically active region of Turkey. For this purpose, properties and dynamic behavior of the Quaternary alluvial soils in study area were assessed. Soil classification, soil amplification, natural soil predominant period, resonance phenomena and liquefaction potential of the study area were evaluated using borehole data and microtremor measurements. The raw data obtained from previous studies carried out at Yenisehir were used for these assessments. Geotechnical microzonation map of Yenisehir was produced according to the surface damage due to liquefaction, soil amplification and distance to streams maps; by using Geographical Information Systems (GIS) based Multi-Criteria Decision Analysis. The weight values were assigned to the layers using Analytical Hierarchical Process method by pairwise comparisons. The produced geotechnical microzonation map indicated that the most critical areas are located in the densely populated middle and the southeastern parts of the study area

Preparation of a geotechnical microzonation model using Geographical Information Systems based on Multicriteria Decision Analysis

The purpose of this study is to develop a geotechnical microzonation model using Geographical Information Systems (GIS) based on Multicriteria Decision Analysis (MCDA). As study area, the Eskisehir downtown area has been chosen. Eskisehir is one of the most rapidly growing cities in central Turkey. The model inputs include slope, flood susceptibility, soil, depth to groundwater table, swelling potential, and liquefaction potential. The weight and rank values are assigned to the layers and to the classes of each layer respectively. The assignment of the weight/rank values and the analysis are realized by the application of two different decision models, namely Simple Additive Weighting (SAW) and Analytic Hierarchy Process (AHP) methods. The geotechnical microzonation maps prepared as outputs of these methods are found to be consistent with each other and confirmed by the experts within the study area. The geotechnical microzonation map prepared using the AHP method is recommended as the final map of the study

Identification of possible source areas of stone raw materials combining remote sensing and petrography

Understanding the location and distribution of raw materials used in the production of prehistoric artefacts is a significant part of archaeological research that aims to understand the interregional interaction patterns in the past. The aim of this study is to explore the regional locations of the source rock utilized in the production of stone bowls, which were unearthed at the Neolithic (approximately 6500–5500 BC) site of Domuztepe (Kahramanmaraş-Turkey), via a combination of remote-sensing methods, petrographic and chemical analyses. To accomplish this task, the stone bowls were identified mineralogically, geochemically and spectrally, and then mapped with Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensors. According to the defined mineralogical composition, which is iron-rich chlorite, the target areas were selected among geologically potential areas that would bear similar source rocks in near vicinity and the target spectral signature was searched within these target areas. In order to overcome the problem of spectral similarity of chlorite group to some other minerals such as carbonate or epidote group minerals, band ratioing (BR) and feature-oriented principal component analysis (FOPCA) were used with an integrated approach and then their results were filtered according to the outcomes of the relative absorption band-depth (RBD) images. The areas with highest potentials were vectorized and then field checked. Mineralogical investigations on the collected field samples reveal that there is a mineralogical match between the source and target material. One group of stone bowls samples have similar geochemical signatures as the field samples having ultramafic origins. However, there is another group of stone bowls samples which are geochemically dissimilar to the first group of field and bowls samples. The data regarding the geochemical signatures of these two groups indicate a genetic relation between the sample sets. Therefore, it is concluded that the source rock of a major portion of the stone bowls unearthed at Domuztepe most probably originated from the near vicinity of the site