Consequently, majority of studies in occupational safety leaned towards describing accidents with the aid of surveys and d escriptive statistics. This study intends to fill this gap by using inferential statistics to identify the factors that contribute to severity of injuries. Subsequently, cooperation with Social Security Institute of Turkey was achieved and an extensive archival study was performed. The information acquired from open-ended questions in forms were reorganized to be identified as variables. Categorically identified data set were analyzed statistically by using binary logistic regression analyses. The findings of the study showed that work experience, accident type, unsafe condition, unsafe act have statistically significant influence on Injury Severity Score.
{"title":"Identifying Factors that Contribute to Severity of Construction Injuries using Logistic Regression Model","authors":"Özge A. Kale, S. Baradan","doi":"10.18400/tekderg.470633","DOIUrl":"https://doi.org/10.18400/tekderg.470633","url":null,"abstract":"Consequently, majority of studies in occupational safety leaned towards describing accidents with the aid of surveys and d escriptive statistics. This study intends to fill this gap by using inferential statistics to identify the factors that contribute to severity of injuries. Subsequently, cooperation with Social Security Institute of Turkey was achieved and an extensive archival study was performed. The information acquired from open-ended questions in forms were reorganized to be identified as variables. Categorically identified data set were analyzed statistically by using binary logistic regression analyses. The findings of the study showed that work experience, accident type, unsafe condition, unsafe act have statistically significant influence on Injury Severity Score.","PeriodicalId":49442,"journal":{"name":"Teknik Dergi","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44710203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Road freight accounts for the 89% of the inland freight transportation in Turkey. This study examined the factors affecting capacity utilization in Turkey with a specific focus on load factors and empty running. These two decisions, the load factor and the choice of running empty, are modelled jointly in a Heckman model. The model results showed that rigid and articulated trucks represent relatively different transport markets. Their age and the distance profile of the shipments affect the load factor and the probability of running empty. These effects are further examined for different commodity types and by testing different econometric specifications.
{"title":"Factors Affecting the Capacity Utilization of Road Freight Transport in Turkey","authors":"Murat Özen, Muhammad Fayyaz, Hediye Tüydeş Yaman","doi":"10.18400/tekderg.413807","DOIUrl":"https://doi.org/10.18400/tekderg.413807","url":null,"abstract":"Road freight accounts for the 89% of the inland freight transportation in Turkey. This study examined the factors affecting capacity utilization in Turkey with a specific focus on load factors and empty running. These two decisions, the load factor and the choice of running empty, are modelled jointly in a Heckman model. The model results showed that rigid and articulated trucks represent relatively different transport markets. Their age and the distance profile of the shipments affect the load factor and the probability of running empty. These effects are further examined for different commodity types and by testing different econometric specifications.","PeriodicalId":49442,"journal":{"name":"Teknik Dergi","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44347864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The concept of time-cost relationship in construction projects was first introduced by Bromilow. Bromilow used the data of the superstructure projects completed in Australia in the creation of the proposed time-cost model (BTC model). The aim of this study is to determine the time-cost relationship of superstructure projects in Turkey. Time and cost data of superstructure projects completed between the years of 1999-2018 was used in the study. Data was grouped primarily on the basis of the intended use of buildings (individual buildings, educational buildings, hospitals, industrial buildings and social housing), and then time-cost relationships were separately determined for each group. In addition, the effects of the parameters such as exchange rates and the number of non-working days on the time-cost relationship were investigated statistically.
{"title":"Time - Cost Relationships for Superstructure Projects in Turkey","authors":"M. Sönmez, S. Ü. Dikmen, R. Akbiyikli","doi":"10.18400/tekderg.456761","DOIUrl":"https://doi.org/10.18400/tekderg.456761","url":null,"abstract":"The concept of time-cost relationship in construction projects was first introduced by Bromilow. Bromilow used the data of the superstructure projects completed in Australia in the creation of the proposed time-cost model (BTC model). The aim of this study is to determine the time-cost relationship of superstructure projects in Turkey. Time and cost data of superstructure projects completed between the years of 1999-2018 was used in the study. Data was grouped primarily on the basis of the intended use of buildings (individual buildings, educational buildings, hospitals, industrial buildings and social housing), and then time-cost relationships were separately determined for each group. In addition, the effects of the parameters such as exchange rates and the number of non-working days on the time-cost relationship were investigated statistically.","PeriodicalId":49442,"journal":{"name":"Teknik Dergi","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42048640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A logistic regression model has been developed for evaluation of soil liquefaction by the use of cone penetration test (CPTu, PCPT) on data collected from Adapazari, Turkey. The model inputs are the clean sand equivalent normalized cone tip resistance ( q c1N,cs ) and cyclic stress ratio corrected for moment magnitude of 7.5 earthquake ( CSR M=7.5 ) that was experienced in 1999. Liquefaction probabilities ( P L ) are obtained for each district of the city for which CPTu data is available with the proposed logistic regression model. Average liquefaction probabilities of the depth interval 0-6 m and coordinates (Longitude, Latitude) of CPT soundings were plotted to construct a liquefaction probability map by longitude and latitude. In order to show the effect of depth in liquefaction potential, the obtained liquefaction probability contours were reconstructed by dividing 0-6m depth into three narrow sublayers of 0-2m, 2-4m and 4-6m wherein liquefaction was observed during the earthquake. For each depth interval, liquefaction probabilities of the districts are compared with the observed liquefied and non-liquefied sites in the city after 1999 Adapazari Earthquake.
{"title":"The Spatial Distribution of Liquefaction Susceptibility by Logistic Regression Model adapted for Adapazari, Turkey","authors":"A. Mert, E. Arel, Akın Önalp","doi":"10.18400/tekderg.445322","DOIUrl":"https://doi.org/10.18400/tekderg.445322","url":null,"abstract":"A logistic regression model has been developed for evaluation of soil liquefaction by the use of cone penetration test (CPTu, PCPT) on data collected from Adapazari, Turkey. The model inputs are the clean sand equivalent normalized cone tip resistance ( q c1N,cs ) and cyclic stress ratio corrected for moment magnitude of 7.5 earthquake ( CSR M=7.5 ) that was experienced in 1999. Liquefaction probabilities ( P L ) are obtained for each district of the city for which CPTu data is available with the proposed logistic regression model. Average liquefaction probabilities of the depth interval 0-6 m and coordinates (Longitude, Latitude) of CPT soundings were plotted to construct a liquefaction probability map by longitude and latitude. In order to show the effect of depth in liquefaction potential, the obtained liquefaction probability contours were reconstructed by dividing 0-6m depth into three narrow sublayers of 0-2m, 2-4m and 4-6m wherein liquefaction was observed during the earthquake. For each depth interval, liquefaction probabilities of the districts are compared with the observed liquefied and non-liquefied sites in the city after 1999 Adapazari Earthquake.","PeriodicalId":49442,"journal":{"name":"Teknik Dergi","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45524187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The heated surface jet discharged into a bay which is connected to a larger body of water through a strait may experience bifurcation in the bay and stratification in the strait. The combined effects of bifurcation and stratification may lead to a substantially greater rise in temperature than the rise expected in case of unrestricted receiving body of water. In this study, the behavior of heated effluents discharged into bays with a restricted access to a large body of water is scrutinized experimentally by the help of a scaled physical model.Dimensional analysis leads to a new dimensionless parameter Ar, area restriction parameter, on which the difference between the excess temperatures at the inlet of the strait for restricted and free receiving mediums, Δ(ΔT/ΔT 0 ) is shown to be strongly dependent.
{"title":"Effects of Straits on Hydro-Thermal Performance of Small Bays","authors":"A. M. Ger","doi":"10.18400/TEKDERG.467567","DOIUrl":"https://doi.org/10.18400/TEKDERG.467567","url":null,"abstract":"The heated surface jet discharged into a bay which is connected to a larger body of water through a strait may experience bifurcation in the bay and stratification in the strait. The combined effects of bifurcation and stratification may lead to a substantially greater rise in temperature than the rise expected in case of unrestricted receiving body of water. In this study, the behavior of heated effluents discharged into bays with a restricted access to a large body of water is scrutinized experimentally by the help of a scaled physical model.Dimensional analysis leads to a new dimensionless parameter Ar, area restriction parameter, on which the difference between the excess temperatures at the inlet of the strait for restricted and free receiving mediums, Δ(ΔT/ΔT 0 ) is shown to be strongly dependent.","PeriodicalId":49442,"journal":{"name":"Teknik Dergi","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43509677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Selim Dündar, Betül Değer Şitilbay, Mustafa Sinan Yardim
In this study, Marshall test results of hot mix asphalt samples having various Hydrated Lime (HL) content rates were modelled using Fuzzy Logic (FL) and Artificial Neural Networks (ANN). Test sets having various HL content were prepared in order to investigate the effect of HL. Marshall Stability test was performed on the samples to obtain the optimal Asphalt Content (AC) ratio. The results were evaluated in order to determine HL additives’ sensitivity on the mixture parameters. The Marshall Test results were used to develop the FL and ANN models. The models developed produced acceptable estimations of the mixture parameters.
{"title":"Modelling the Effects of Hydrated Lime Additives on Asphalt Mixtures by Fuzzy Logic and ANN","authors":"Selim Dündar, Betül Değer Şitilbay, Mustafa Sinan Yardim","doi":"10.18400/TEKDERG.402816","DOIUrl":"https://doi.org/10.18400/TEKDERG.402816","url":null,"abstract":"In this study, Marshall test results of hot mix asphalt samples having various Hydrated Lime (HL) content rates were modelled using Fuzzy Logic (FL) and Artificial Neural Networks (ANN). Test sets having various HL content were prepared in order to investigate the effect of HL. Marshall Stability test was performed on the samples to obtain the optimal Asphalt Content (AC) ratio. The results were evaluated in order to determine HL additives’ sensitivity on the mixture parameters. The Marshall Test results were used to develop the FL and ANN models. The models developed produced acceptable estimations of the mixture parameters.","PeriodicalId":49442,"journal":{"name":"Teknik Dergi","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46223943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Considering the competitive environment in all industries, completion on time is crucial for the stakeholders of a project. This favorable target is achieved by finding the optimal set of time-cost alternatives and this is known as time-cost trade-off problem (TCTP) in the literature. In this study, a new initial population approach is presented to improve the quality of the optimal set of time-cost alternatives. It put a predefined number of the solutions of the single objective TCTP into the initial population of teaching learning-based algorithm, which is utilized as an optimizer for the multi-objective optimization of TCTP. Hence, it is aimed to descend the randomness on initial population and to decrease the searching effort to catch the optimal set of time-cost alternatives in the search space. The proposed methodology is tested on a series of benchmark problems and the obtained results are compared with those available in the technical literature. It can produce good solutions as effective as with other techniques applied for simultaneous optimization of TCTPs.
{"title":"Time-Cost Trade-Off Optimization with a New Initial Population Approach","authors":"V. Toğan, M. A. Eirgash","doi":"10.18400/TEKDERG.410934","DOIUrl":"https://doi.org/10.18400/TEKDERG.410934","url":null,"abstract":"Considering the competitive environment in all industries, completion on time is crucial for the stakeholders of a project. This favorable target is achieved by finding the optimal set of time-cost alternatives and this is known as time-cost trade-off problem (TCTP) in the literature. In this study, a new initial population approach is presented to improve the quality of the optimal set of time-cost alternatives. It put a predefined number of the solutions of the single objective TCTP into the initial population of teaching learning-based algorithm, which is utilized as an optimizer for the multi-objective optimization of TCTP. Hence, it is aimed to descend the randomness on initial population and to decrease the searching effort to catch the optimal set of time-cost alternatives in the search space. The proposed methodology is tested on a series of benchmark problems and the obtained results are compared with those available in the technical literature. It can produce good solutions as effective as with other techniques applied for simultaneous optimization of TCTPs.","PeriodicalId":49442,"journal":{"name":"Teknik Dergi","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45998973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ayşegül Güneş Seferoğlu, Mehmet Tevfik Seferoğlu, M. Akpınar
The objective of this research is to assess the elastic deformations and permanent strains of reclaimed asphalt pavement (RAP) material as a base layer when it is treated or untreated with puzzolanic cement under cyclic loads. A large-scale cyclic plate loading testing (CPLT) device was developed for studying the mechanical characteristics of pavement base layer materials. When the RAP percentage of the mixtures increased, elastic deformations and permanent strains increased, but the opposite is true when the cement percentage increased. It was concluded that 100% RAP material can be used in base layers with 3% cement. The obtained deformation values and strain rates can be used as reasonable default design input values to be used by pavement designers when using RAP as a substitute for natural aggregate base layers.
{"title":"Investigating the Mechanical Behavior of Reclaimed Asphalt Pavement (RAP) Bases in Large Scale Test Box","authors":"Ayşegül Güneş Seferoğlu, Mehmet Tevfik Seferoğlu, M. Akpınar","doi":"10.18400/TEKDERG.416812","DOIUrl":"https://doi.org/10.18400/TEKDERG.416812","url":null,"abstract":"The objective of this research is to assess the elastic deformations and permanent strains of reclaimed asphalt pavement (RAP) material as a base layer when it is treated or untreated with puzzolanic cement under cyclic loads. A large-scale cyclic plate loading testing (CPLT) device was developed for studying the mechanical characteristics of pavement base layer materials. When the RAP percentage of the mixtures increased, elastic deformations and permanent strains increased, but the opposite is true when the cement percentage increased. It was concluded that 100% RAP material can be used in base layers with 3% cement. The obtained deformation values and strain rates can be used as reasonable default design input values to be used by pavement designers when using RAP as a substitute for natural aggregate base layers.","PeriodicalId":49442,"journal":{"name":"Teknik Dergi","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46769164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Turbulent flow characteristics around a partially buried horizontal circular cylinder are investigated numerically for the burial ratio of B/D =0.50. The governing equations are numerically solved using ANSYS-Fluent for the flows having the same conditions with the experiments related to measurements of velocity field by Particle Image Velocimetry for Reynolds numbers based on the cylinder diameter, in the ranges of 1000 ≤ Re D ≤ 7000 . Standard k - e , Renormalization-group k - e , Realizable k - e , Modified k - ω , Shear Stress Transport k - w and Reynolds Stress turbulence models are employed. Experimental validations of the numerical results show that Shear Stress Transport k - w model provides better predictions for the kinematic properties of the t urbulent flow than the other turbulence models used herein. Force coefficients also predicted numerically at Reynolds numbers in the ranges of 1000 £ Re D £ 7000 for the burial ratio, B/D =0, 0.25 and 0.5.
{"title":"Numerical Modeling of Interaction of Vortical Flow with a Buried Circular Cylinder on a Plane Surface","authors":"M. Aköz, O. Şimşek, N. G. Soydan","doi":"10.18400/TEKDERG.432310","DOIUrl":"https://doi.org/10.18400/TEKDERG.432310","url":null,"abstract":"Turbulent flow characteristics around a partially buried horizontal circular cylinder are investigated numerically for the burial ratio of B/D =0.50. The governing equations are numerically solved using ANSYS-Fluent for the flows having the same conditions with the experiments related to measurements of velocity field by Particle Image Velocimetry for Reynolds numbers based on the cylinder diameter, in the ranges of 1000 ≤ Re D ≤ 7000 . Standard k - e , Renormalization-group k - e , Realizable k - e , Modified k - ω , Shear Stress Transport k - w and Reynolds Stress turbulence models are employed. Experimental validations of the numerical results show that Shear Stress Transport k - w model provides better predictions for the kinematic properties of the t urbulent flow than the other turbulence models used herein. Force coefficients also predicted numerically at Reynolds numbers in the ranges of 1000 £ Re D £ 7000 for the burial ratio, B/D =0, 0.25 and 0.5.","PeriodicalId":49442,"journal":{"name":"Teknik Dergi","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47067815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, a hypothetical tall building structure consisting of two towers and a common podium is analyzed considering effects of interaction between the towers due to connected podium floors. Interaction effects on the podium level are included in the analyses by embracing either an upper bound or lower bound approach, assigning fixed or free end restraints at the continuous boundaries of single tower models, respectively. Response of single tower models are then compared with the response obtained from combined model which includes both of the towers as well as the common podium and basements. Obtained results indicate that, in both linear and nonlinear analyses, single tower models with fixed end restraints overestimate internal forces at the podium floors, although to a reasonable extent.
{"title":"Earthquake Response Analysis of Multiple Towers on a Common Podium: A Representative Case Study","authors":"C. Tura, K. Orakcal","doi":"10.18400/TEKDERG.467371","DOIUrl":"https://doi.org/10.18400/TEKDERG.467371","url":null,"abstract":"In this study, a hypothetical tall building structure consisting of two towers and a common podium is analyzed considering effects of interaction between the towers due to connected podium floors. Interaction effects on the podium level are included in the analyses by embracing either an upper bound or lower bound approach, assigning fixed or free end restraints at the continuous boundaries of single tower models, respectively. Response of single tower models are then compared with the response obtained from combined model which includes both of the towers as well as the common podium and basements. Obtained results indicate that, in both linear and nonlinear analyses, single tower models with fixed end restraints overestimate internal forces at the podium floors, although to a reasonable extent.","PeriodicalId":49442,"journal":{"name":"Teknik Dergi","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43965959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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