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Öğe Assessing the Water Quality Parameters of the Munzur Spring, Tunceli, Turkey(Foundation Environmental Protection & Research-Fepr, 2014) Celiker, Murat; Yildiz, Osman; Sonmezer, Yetis BulentThis study presents an analysis of the temporal variations in the upstream water quality parameters of the Munzur Spring. For this purpose, the spring water quality was monitored from 2007 to 2009 at different time periods. There were 5 water samples taken from 2008 to 2009 for hydrochemical and biological analyses, while 6 water samples were gathered between 2007 and 2009 for heavy metal analysis. The analysis results reveal that the water quality parameters were found to be in good agreement with the drinking water standards of Anonymous (1993) and Anonymous (2005). It was seen that the upstream source of the Munzur spring is periodically characterized by Ca+2 - Mg+2 - HCO3- and Ca+2 - Cl- - HCO3- facies according to Anonymous (1978), and CaCO3 and CaCl2 facies according to Back (1960, 1966). The results of a tritium analysis indicated that the spring is recharged by daily precipitations. The spring water was also found suitable for irrigation purposes based on Wilcox and US salinity diagrams.Öğe Assessment of the peak acceleration, amplification ratio and fundamental period properties for the kirikkale province settlement area(Gazi Univ, Fac Engineering Architecture, 2015) Sonmezer, Yetis Bulent; Akbas, Sami Oguzhan; Isik, Nihat SinanDue to its proximity to active fault zones such as Bala, Seyfe, Karakecili, Kirikkale-Sungurlu and Keskin, the province of Kirikkale is classified within the highest earthquake hazard zone in accordance to the Turkish Earthquake Code. In this study; a site-specific site response analysis was performed using equivalent linear method to estimate the local site effects on seismic ground motions and for guidance to the future construction activities. For this purpose, geotechnical and geophysical data compiled from 107 soil exploration borings, 15 seismic refraction and 6 MASW tests were employed. In the analyses, the ground motion record of the 1999 Duzce Earthquake from the Lamont-1061 station was used. The spatial distribution of peak ground acceleration, soil amplification ratio and the fundamental period are presented as maps. The results indicate high ground acceleration and medium-high period values within the study area.Öğe Determination of seismic hazard and soil response of a critical region in Turkey considering far-field and near-field earthquake effect(TECHNO-PRESS, 2020) Sonmezer, Yetis Bulent; Celiker, MuratEvaluation of earthquake impacts in settlements with a high risk of earthquake occurrence is important for the determination of site-specific dynamic soil parameters and earthquake-resistant structural planning. In this study, dynamic soil properties of Karliova (Bingol) city center, located near to the intersection point of the North Anatolian Fault Zone and the East Anatolian Fault Zone and therefore having a high earthquake risk, were investigated by one-dimensional equivalent linear site response analysis. From ground response analyses, peak ground acceleration, predominant site period, 0.2-sec and 1-sec spectral accelerations and soil amplification maps of the study area were obtained for both near-field and far-field earthquake effects. The average acceleration spectrum obtained from analysis, for a near-field earthquake scenario, was found to exceed the design spectra of the Turkish Earthquake Code and Eurocode 8. Yet, the average acceleration spectrum was found to remain below the respective design spectra of the two codes for the far-field earthquake scenario. According to both near- and far-field earthquake scenarios in the study area, the low-rise buildings with low modal vibration durations are expected to be exposed to high spectral acceleration values and high-rise buildings with high modal vibration durations will be exposed to lower spectral accelerations. While high amplification ratios are observed in the north of the study area for the near-distance earthquake scenario, high amplification ratios are observed in the south of the study area for the long-distance earthquake scenario.Öğe Energy-based evaluation of liquefaction potential of uniform sands(Techno-Press, 2019) Sonmezer, Yetis BulentSince behaviors of loose, dense, silty sands vary under seismic loading, understanding the liquefaction mechanism of sandy soils continues to be an important challenges of geotechnical earthquake engineering. In this study, 36 deformation controlled cyclic simple shear tests were performed and the liquefaction potential of the sands was investigated using three different relative densities (40, 55, 70%), four different effective stresses (25, 50, 100, 150 kPa) and three different shear strain amplitudes (2, 3.5, 5%) by using energy based approach. Experiments revealed the relationship between per unit volume dissipated energy with effective stress, relative density and shear strain. The dissipate energy per unit volume was much less affected by shear strain than effective stress and relative density. In other words, the dissipated energy is strongly dependent on relative density and effective stress. These results show that the dissipated energy per unit volume is very useful and may contain the non-uniform loading conditions of the earthquake spectrum. When multiple regression analysis is performed on experiment results, a relationship is proposed that gives liquefaction energy of sandy soils depending on relative density and effective stress parameters.Öğe Estimation of the soil liquefaction potential through the Krill Herd algorithm(Techno-Press, 2023) Sonmezer, Yetis Bulent; Korkmaz, ErsinLooking from the past to the present, the earthquakes can be said to be type of disaster with most casualties among natural disasters. Soil liquefaction, which occurs under repeated loads such as earthquakes, plays a major role in these casualties. In this study, analytical equation models were developed to predict the probability of occurrence of soil liquefaction. In this context, the parameters effective in liquefaction were determined out of 170 data sets taken from the real field conditions of past earthquakes, using WEKA decision tree. Linear, Exponential, Power and Quadratic models have been developed based on the identified earthquake and ground parameters using Krill Herd algorithm. The Exponential model, among the models including the magnitude of the earthquake, fine grain ratio, effective stress, standard penetration test impact number and maximum ground acceleration parameters, gave the most successful results in predicting the fields with and without the occurrence of liquefaction. This proposed model enables the researchers to predict the liquefaction potential of the soil in advance according to different earthquake scenarios. In this context, measures can be realized in regions with the high potential of liquefaction and these measures can significantly reduce the casualties in the event of a new earthquake.Öğe Evaluation of the seismic site characterization of Kovancilar (Elazig), Turkey(Springer Heidelberg, 2024) Sonmezer, Yetis Bulent; Celiker, Murat; Simsek, HilalThe effect of seismic waves on structures during an earthquake varies depending on local ground conditions. This study is dedicated to determining the seismic site characterization of Kovancilar district in the city of Elazig, Turkey, whose location is close (5 km) to the East Anatolian Fault Zone (EAFZ), one of the most active fault zones all around globe. For this purpose, 1-D equivalent linear soil behavior analyzes were performed using 28 geotechnical drilling and 20 multi-channel surface wave (MASW) test data in the study area. The results of these analyses indicated the peak ground acceleration (PGA) values in Kovancilar ranged between 0.41 and 0.68 g, while high PGA values were observed in the region of alluvial soils in the south of the district. The acceleration spectra obtained from the analyses on three different locations were compared to the Turkish Building Seismic Regulation 2018 (TBSR 2018) and Eurocode 8 (EC-8 2004) design spectra. For some periods, the acceleration values in the site-specific spectra were observed to exceed the related values in the TBSR 2018 ZC and ZD design spectra. In addition, ground amplification, PGA, and spectral acceleration (Sa) maps with 0.2-1 s periods were created for the study area. With the evaluation of the obtained parameters, the north of the region was established to be more suitable for multi-story buildings, while the northeast, east, and southeast regions being more suitable for low-rise buildings.Öğe Influence of grain size ratio and silt content on the liquefaction potentials of silty sands(Techno-Press, 2022) Sonmezer, Yetis Bulent; Kayabali, Kamil; Beyaz, Turgay; Fener, MustafaSoil liquefaction has been one of the most important concerns in geotechnical earthquake engineering in recent years, due to its damages to structures and its destructive effects. The cyclic liquefaction of silty sands, in particular, remains of great interest for both research and application. Although many factors are known that affect the liquefaction resistance of sands, the effect of fine grain content is perhaps one of the most studied and still controversial. In this study, 48 deformation-controlled cyclic simple shear tests were performed on BS and CS silt samples mixed with 5%, 15% and 30% by weight of Krk085, Krk042 and Krk025 sands in constant-volume conditions to determine the liquefaction potential of silty sands. The tests were carried out at 30% and 50% relative density and under 100 kPa effective stress. The results revealed that the liquefaction potential of silty sand increases with increasing average particle size ratio (D50sand/ d50silt) of the mixture for a fixed silt content. Furthermore, for identical base sand, the liquefaction potentials of coarse grained sands increase with increasing silt content, while the respective potentials of fine grained sands generally decrease. However, this situation may vary depending on the silt grain structure and is affected by the nature of the fine grains. In addition, the variation of the void ratio interval was shown to provide a good intuition in determining the liquefaction potentials of silty sands, while the intergranular void ratio alone does not constitute a criterion for determining the liquefaction potentials of silty sands.Öğe Investigation of the earthquake-induced liquefaction and seismic amplifications after Pazarcık (Mw 7.7) and Elbistan (Mw 7.6) earthquakes(Springer, 2024) Yildiz, Ozgur; Zeybek, Abdulhakim; Sonmezer, Yetis BulentThe earthquakes in Pazarc & imath;k (Mw 7.7) and Elbistan (Mw 7.6), occurring along the East Anatolian Fault Zone (EAFZ) on February 6, 2023, caused significant damage and destruction to the built environment within the affected area. In this study, the preliminary site investigations were conducted in the G & ouml;lba & scedil;& imath; district, where the impacts of both earthquakes were severely felt, offering scientifically valuable information regarding the soil damage. Comprehensive liquefaction analyses were performed using the geotechnical laboratory test data on soil specimens collected from the G & ouml;lba & scedil;& imath; district. These analyses confirmed the liquefaction-induced ground failures observed immediately after the two earthquakes. Furthermore, microzonation data collected in the G & ouml;lba & scedil;& imath; district were consolidated, and seismic site response analyses were conducted. Simulations showed that local soils in the region could amplify seismic waves by a factor of two. Utilizing the calculated Peak Ground Acceleration (PGA) and amplification factors, GIS-based distribution maps of the entire area were developed. These maps serve as practical resources for practitioners and local planners, aiding in spatial settlement decisions and urban transformation planning. They contribute significantly to enhancing the understanding of earthquake hazards in the region.Öğe Investigation of the effect of grain size on liquefaction potential of sands(TECHNO-PRESS, 2020) Sonmezer, Yetis Bulent; Akyuz, Abdussamed; Kayabali, KamilDue to the permanent damage to structures during earthquakes, soil liquefaction is an important issue in geotechnical earthquake engineering that needs to be investigated. Typical examples of soil liquefaction have been observed in many earthquakes, particularly in Alaska, Niigata (1964), San Fernando (1971), Loma Prieta (1989), Kobe (1995) and Izmit (1999) earthquakes. In this study, liquefaction behavior of uniform sands of different grain sizes was investigated by using the energy-based method. For this purpose, a total of 36 deformation-controlled tests were conducted on water-saturated samples in undrained conditions by using the cyclic simple shear test method and considering the relative density, effective stress and mean grain size parameters that affect the cumulative liquefaction energy. The results showed that as the mean grain size decreases, the liquefaction potential of the sand increases. In addition, with increasing effective stress and relative density, the resistance of sand against liquefaction decreases. Multiple regression analysis was performed on the test results and separate correlations were proposed for the samples with mean grain size of 0.11-0.26 mm and for the ones with 0.45-0.85 mm. The recommended relationships were compared to the ones existing in the literature and compatible results were obtained.Öğe Investigation of the liquefaction potential of fiber-reinforced sand(Techno-Press, 2019) Sonmezer, Yetis BulentIn the present, the liquefaction potential of fiber-reinforced sandy soils was investigated through the energy-based approach by conducting a series of strain-controlled cyclic simple shear tests. In the tests, the effects of the fiber properties, such as the fiber content, fiber length, relative density and effective stress, and the test parameters on sandy soil improvement were investigated. The results indicated that the fiber inclusion yields to higher cumulative liquefaction energy values compared to the unreinforced (plain) ground by increasing the number of cycles and shear strength needed for the liquefaction of the soil. This result reveals that the fiber inclusion increases the resistance of the soil to liquefaction. However, the increase in the fiber content was determined to be more effective on the test results compared to the fiber length. Furthermore, the increase in the relative density of the soil increases the efficiency of the fibers on soil strengthening.Öğe Linear and nonlinear site response analyses to determine dynamic soil properties of Kirikkale(Techno-Press, 2018) Sonmezer, Yetis Bulent; Bas, Selcuk; Isik, Nihat Sinan; Akbas, Sami OguzhanIn order to make reliable earthquake-resistant design of civil engineering structures, one of the most important considerations in a region with high seismicity is to pay attention to the local soil condition of regions. It is aimed in the current study at specifying dynamic soil characteristics of Kirikkale city center conducting the 1-D equivalent linear and non-linear site response analyses. Due to high vulnerability and seismicity of the city center of Kirikkale surrounded by active many faults, such as the North Anatolian Fault (NAF), the city of Kirikkale is classified as highly earthquake-prone city. The first effort to determine critical site response parameter is to perform the seismic hazard analyses of the region through the earthquake record catalogues. The moment magnitude of the city center is obtained as M-W,=7.0 according to the recorded probability of exceedance of 10% in the last 50 years. Using the data from site tests, the 1-D equivalent linear (EL) and nonlinear site response analyses (NL) are performed with respect to the shear modulus reduction and damping ratio models proposed in literature. The important engineering parameters of the amplification ratio, predominant site period, peak ground acceleration (PGA) and spectral acceleration values are predicted. Except for the periods between the period of T=12-1.0 s, the results from the NL are obtained to be similar to the EL results. Lower spectral acceleration values are estimated in the locations of the city where the higher amplification ratio is attained or vice-versa. Construction of high-rise buildings with modal periods higher than T=1.0 s are obtained to be suitable for the city of Kirikkale. The buildings at the city center are recommended to be assessed with street survey rapid structural evaluation methods so as to mitigate seismic damages. The obtained contour maps in this study are estimated to be effective for visually characterizing the city in terms of the considered parameters.Öğe Seismic performance and damage assessment of bridges during the 2023 Kahramanmaras, Türkiye earthquakes (Mw = 7.8, Mw = 7.6)(Sage Publications Inc, 2024) Bas, Selcuk; Hunt, Jeffrey; Gencturk, Bora; Jampole, Ezra; Sonmezer, Yetis Bulent; Chancellor, Brent; Bassal, PatrickThis article presents a summary of the damage observed in bridges in the regions affected by the 6 February 2023 Kahramanmaras, T & uuml;rkiye earthquake sequence. A bridge database was developed based on the observations from multiple reconnaissance groups that visited the bridges. These reconnaissance groups collectively visited 140 individual bridges that were subjected to various intensities of ground shaking. The severity of the observed damage ranged from no damage to total collapse. The types of damage to bridge components mainly included cracking and shifting of abutments, failure of pier cap shear blocks, shifting or dislodging of bearing pads, cracking of girders and loss of prestress, plastic hinging at pier bases, residual pier drift, and distress to deck surfaces, handrails, and carried utilities. Recorded and estimated seismic intensity measures are presented for each bridge site, and statistical information and correlations were developed considering the intensity of shaking, bridge parameters, and observed damage. Observations from a few visited sites are presented as case studies to illustrate the common failure mechanisms. The bridge database and presented results are expected to serve as a reference for further analysis, such as statistical verification, correlation, or damage estimations, and discussion regarding the mitigation of the observed vulnerabilities of bridges in T & uuml;rkiye and those with similar construction worldwide.Öğe Seismic risk estimation of the Kirikkale province through street survey based rapid assessment method (SSRA)(Techno-Press, 2018) Sonmezer, Yetis Bulent; Bas, Selcuk; Akbas, Sami OguzhanThe seismic vulnerability of Turkey is relatively high due to its active fault systems with potential to create destructive earthquakes. Thus, reducing the loss of life and property, the number of the earthquake-prone buildings and their retrofit requirements are considerably significant key issues under the scenario earthquakes. The street survey based rapid assessment (SSRA) method can be considered as a powerful tool to determine the seismic vulnerability of building stock of an earthquake-prone city/state. In this study, the seismic vulnerability of the building stock of the Kirikkale province in Turkey is aimed to be estimated adopting the street survey based rapid assessment method (SSRA). For this purpose, central 2074 existing reinforced concrete (R/C) buildings were structurally surveyed with rapid visual site screening and disadvantages such as, the existence of short-column, soft-story, heavy overhangs, pounding effect and local soil conditions were determined for obtaining the structural performance score of each. The results obtained from the study demonstrate that 11-25% of the surveyed buildings in the study region needs to be investigated through more advanced assessment methods. Besides, higher correlation between increasing story number and unsafe/safe building ratio is obtained for the buildings with soft-story parameter than that for those with heavy overhangs and short-column parameters. The conformity of the results of the current study with the previous documented cases of rapid assessment efforts in the recent earthquakes in Turkey shows that the SSRA method for the Kirikkale province performed well, and thus this methodology can be reliably used for similar settlement areas.
