ÖZGÜR YILDIZ - Academia.edu (original) (raw)
Papers by ÖZGÜR YILDIZ
European Journal of Science and Technology, 2022
The non-linear nature of the soils can cause the parameters to change significantly even in a lim... more The non-linear nature of the soils can cause the parameters to change significantly even in a limited area. In site investigation studies, the sampling frequency is important in determining soil properties with sufficient accuracy and in developing an idealized soil profile in which the engineering design will be made. Statistical methods are used in cases where field studies cannot be done adequately due to technical limitations, unsuitability of the study area and cost problems. These methods usually provide important information about the soil at the preliminary design stage. While statistical methods are used by researchers and practitioners to obtain soil parameters, no study has been found in the literature on the use of these methods in artificially filled areas. In this study, the soil parameters of the filled area created in the Yenikapı, İstanbul with an area of 715.000 m 2 were examined. In this context, empirical correlations have been developed between the parameters obtained by the geotechnical tests carried out and the relationships between the soil parameters have been revealed. The data obtained from pressuremeter and standart penetration tests were used in correlations. The developed correlations were compared with the empirical correlations developed for natural soils and important findings were obtained.
International Journal of Innovative Engineering Applications, 2021
Original scientific paper In existing buildings, it may be necessary to repair, adapt, renew, rel... more Original scientific paper In existing buildings, it may be necessary to repair, adapt, renew, relocate or demolish buildings and building parts that have come to the end of their usage period due to spatial, functional, technical and economic obsolescence. After the necessary applications to extend the service life of buildings, it is of great importance to analyze the dynamic behavior of buildings under soil-structure interaction and earthquake loads and to obtain accurate results. In this study, the seismic soil-structure interaction of the historical Sungur Bey Mosque, which was first built in 1577 but was disassembled, moved and rebuilt in another area (relocated) in order to preserve its historical and cultural values and extend its service life, was examined. The analysis of the masonry structure that survived after the Sivrice (2020) earthquake, where the great loss of life and property occurred, was carried out with the PLAXIS 3D software program. The real record of the Sivrice NS (2020) earthquake was used in dynamic analysis. Local soil properties obtained as a result of field investigation studies were utilized in numerical modeling. Depending on the result of the analyzes, the effects of soil-structure interaction on a reconstructed historical masonry structure were examined. The results obtained from the analysis showed that the local soil conditions have an amplification effect on seismic waves that may induce structural damages in prospective seismic events.
Eskişehir Technical University Journal of Science and Technology A - Applied Sciences and Engineering, 2021
NATURENGS MTU Journal of Engineering and Natural Sciences Malatya Turgut Ozal University, 2021
Teknik Dergi, 2020
The greywackes are the common soil formation of Istanbul locally known as the Trakya Formation. I... more The greywackes are the common soil formation of Istanbul locally known as the Trakya Formation. It is mostly weathered and extensively fractured. The stress relief induced by deep excavations causes excessive displacements in horizontal direction. As a result, predicting excavation-induced wall displacements is critical for avoiding collapse. The aim of this study is to develop an Artificial Neural Network (ANN) model to predict anchored-pile-wall displacements at different stages of excavation performed on Istanbul's greywacke formations. A database was created on excavation and monitoring data from 11 individual projects. Five variables were used as input parameters, namely, excavation depth, maximum ground settlement measured behind the wall, system stiffness, standard penetration test N value of the soil depth, and index-of-observation. The proposed model was trained, validated, and tested. Finally, two distinct projects were numerically modeled by applying the finite element method (FEM) and then used to test the performance of the ANN model. The displacements predicted by the ANN model were compared with both the computed values obtained from the FEM analysis and in situ measured displacements. The proposed ANN model accurately predicted the displacement of anchored pile walls constructed in greywackes at different stages of excavation.
NATURENGS MTU Journal of Engineering and Natural Sciences Malatya Turgut Ozal University, 2021
The effect of local soil characteristics on the propagation of earthquake waves has been commonly... more The effect of local soil characteristics on the propagation of earthquake waves has been commonly studied by researchers. However, the validity of the results obtained by these studies is limited only to the relevant soil conditions. The main purpose of this study is to examine the effect of soil conditions on the propagation of seismic waves in Istanbul. In this regard, soil information belonging to different districts of Istanbul has been compiled. The site response analysis was simulated using a time-domain non-linear response analysis based on the effective stress method and frequency-domain equivalent linear analysis based on the total stress method. A widely used one-dimensional response analysis program DEEPSOIL was used to estimate the soil response of the sites. Modeled soil profiles were subjected to 1999 Kocaeli earthquake motion and the results of the analysis are presented as spectral acceleration, PGA and lateral displacements. The results obtained from both of the analyses were evaluated comparatively in terms of the effect of soil properties on the propagation of the seismic waves. The effect of the analysis method based on different approaches on the results is examined. Substantial findings have been revealed regarding how the propagation of the earthquake waves is affected by local soil conditions. The liquefaction potential of soil profiles was also evaluated using the data of the soil properties of the investigation area.
European Journal of Science and Technology, 2022
The non-linear nature of the soils can cause the parameters to change significantly even in a lim... more The non-linear nature of the soils can cause the parameters to change significantly even in a limited area. In site investigation studies, the sampling frequency is important in determining soil properties with sufficient accuracy and in developing an idealized soil profile in which the engineering design will be made. Statistical methods are used in cases where field studies cannot be done adequately due to technical limitations, unsuitability of the study area and cost problems. These methods usually provide important information about the soil at the preliminary design stage. While statistical methods are used by researchers and practitioners to obtain soil parameters, no study has been found in the literature on the use of these methods in artificially filled areas. In this study, the soil parameters of the filled area created in the Yenikapı, İstanbul with an area of 715.000 m 2 were examined. In this context, empirical correlations have been developed between the parameters obtained by the geotechnical tests carried out and the relationships between the soil parameters have been revealed. The data obtained from pressuremeter and standart penetration tests were used in correlations. The developed correlations were compared with the empirical correlations developed for natural soils and important findings were obtained.
International Journal of Innovative Engineering Applications, 2021
Original scientific paper In existing buildings, it may be necessary to repair, adapt, renew, rel... more Original scientific paper In existing buildings, it may be necessary to repair, adapt, renew, relocate or demolish buildings and building parts that have come to the end of their usage period due to spatial, functional, technical and economic obsolescence. After the necessary applications to extend the service life of buildings, it is of great importance to analyze the dynamic behavior of buildings under soil-structure interaction and earthquake loads and to obtain accurate results. In this study, the seismic soil-structure interaction of the historical Sungur Bey Mosque, which was first built in 1577 but was disassembled, moved and rebuilt in another area (relocated) in order to preserve its historical and cultural values and extend its service life, was examined. The analysis of the masonry structure that survived after the Sivrice (2020) earthquake, where the great loss of life and property occurred, was carried out with the PLAXIS 3D software program. The real record of the Sivrice NS (2020) earthquake was used in dynamic analysis. Local soil properties obtained as a result of field investigation studies were utilized in numerical modeling. Depending on the result of the analyzes, the effects of soil-structure interaction on a reconstructed historical masonry structure were examined. The results obtained from the analysis showed that the local soil conditions have an amplification effect on seismic waves that may induce structural damages in prospective seismic events.
Eskişehir Technical University Journal of Science and Technology A - Applied Sciences and Engineering, 2021
NATURENGS MTU Journal of Engineering and Natural Sciences Malatya Turgut Ozal University, 2021
Teknik Dergi, 2020
The greywackes are the common soil formation of Istanbul locally known as the Trakya Formation. I... more The greywackes are the common soil formation of Istanbul locally known as the Trakya Formation. It is mostly weathered and extensively fractured. The stress relief induced by deep excavations causes excessive displacements in horizontal direction. As a result, predicting excavation-induced wall displacements is critical for avoiding collapse. The aim of this study is to develop an Artificial Neural Network (ANN) model to predict anchored-pile-wall displacements at different stages of excavation performed on Istanbul's greywacke formations. A database was created on excavation and monitoring data from 11 individual projects. Five variables were used as input parameters, namely, excavation depth, maximum ground settlement measured behind the wall, system stiffness, standard penetration test N value of the soil depth, and index-of-observation. The proposed model was trained, validated, and tested. Finally, two distinct projects were numerically modeled by applying the finite element method (FEM) and then used to test the performance of the ANN model. The displacements predicted by the ANN model were compared with both the computed values obtained from the FEM analysis and in situ measured displacements. The proposed ANN model accurately predicted the displacement of anchored pile walls constructed in greywackes at different stages of excavation.
NATURENGS MTU Journal of Engineering and Natural Sciences Malatya Turgut Ozal University, 2021
The effect of local soil characteristics on the propagation of earthquake waves has been commonly... more The effect of local soil characteristics on the propagation of earthquake waves has been commonly studied by researchers. However, the validity of the results obtained by these studies is limited only to the relevant soil conditions. The main purpose of this study is to examine the effect of soil conditions on the propagation of seismic waves in Istanbul. In this regard, soil information belonging to different districts of Istanbul has been compiled. The site response analysis was simulated using a time-domain non-linear response analysis based on the effective stress method and frequency-domain equivalent linear analysis based on the total stress method. A widely used one-dimensional response analysis program DEEPSOIL was used to estimate the soil response of the sites. Modeled soil profiles were subjected to 1999 Kocaeli earthquake motion and the results of the analysis are presented as spectral acceleration, PGA and lateral displacements. The results obtained from both of the analyses were evaluated comparatively in terms of the effect of soil properties on the propagation of the seismic waves. The effect of the analysis method based on different approaches on the results is examined. Substantial findings have been revealed regarding how the propagation of the earthquake waves is affected by local soil conditions. The liquefaction potential of soil profiles was also evaluated using the data of the soil properties of the investigation area.