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Öğe 19 May 2011 Kutahya - Simav earthquake and evaluation of existing sample RC buildings according to the TEC-2007 criteria(COPERNICUS GESELLSCHAFT MBH, 2013) Arslan, M. H.; Olgun, M.; Koroglu, M. A.; Erkan, I. H.; Koken, A.; Tan, O.This study examines the damage caused to reinforced concrete structures by the 2011 earthquake that occurred in Simav, Turkey. The study briefly reports on post-earthquake field observations, tectonic characteristics of the earthquake area, geotechnical characteristics of the field, and seismic characteristics of the earthquake. The main part of the study comprises a field study, material experiments, and performance analyses of two reinforced concrete buildings that survived the earthquake with medium level damage. The building performance was calculated and assessed according to the Turkish Earthquake Code requirements for existing building stock, and recommendations were made based on the findings.Öğe AN ANN APPROACHES ON ESTIMATING EARTHQUAKE PERFORMANCES OF EXISTING RC BUILDINGS(ACAD SCIENCES CZECH REPUBLIC, INST COMPUTER SCIENCE, 2012) Arslan, M. H.; Ceylan, M.; Koyuncu, T.This study aims at developing an artificial intelligence-based (ANN based) analytical method to analyze earthquake performances of the reinforced concrete (RC) buildings. In the scope of the present study, 66 real RC buildings with four to ten storeys were subject to performance analysis according to 19 parameters considered effective on the performance of R,C buildings. In addition, the level of performance of these buildings in case of an earthquake was determined on the basis of the 4-grade performance levels specified in Turkish Earthquake Code-2007 (TEC-2007). Thus, an output performance data group was created for the analyzed buildings, in accordance with the input data. Thanks to the ANN-based fast evaluation algorithm mentioned above and developed within the scope of the proposed project study, it will be possible to make an economic and rapid evaluation of four to ten-storey RC buildings in Turkey with great accuracy (about 80%). Detection of post-earthquake performances of RC buildings in the scope of the present study will facilitate reaching important results in terms of buildings, which will be beneficial for Civil Engineers of Turkey and similar countries.Öğe Damage and Failure Pattern of Prefabricated Structures After Major Earthquakes in Turkey and Shortfalls of the Turkish Earthquake Code(Pergamon-Elsevier Science Ltd, 2006) Arslan, M. H.; Korkmaz, H. H.; Gülay, F. G.The cost of the damage of the earthquakes in the last 10 years has been serious especially on prefabricated industrial structures. Therefore in this study, extensive, serious damage and failures in prefabricated reinforced concrete structures in the August-17, 1999 Adapazari (Turkey) and November-12, 1999 Duzce (Turkey) earthquakes have been examined. By performing a cause and effect assessment of the damage types experienced, some strengthening recommendations have been made. To investigate the causes of the damage beside the assessment of practical imperfections, a comparison between the sets of criteria encompassed in the Turkish Code, UBC-97 and Eurocode-8-98 Codes especially on the criteria of base shear force, displacement and loads acting on the nodes/connections has been made. For the sake of a more comprehensible illustration of the distinctions, the design of a pre-constructed industrial structure to the three mentioned codes has been conducted. In order to compare the above-mentioned codes a sample prefabricated structure, which totally failed after 1999 Marmara earthquake is analysed.Öğe Effect of Internal and External Shear Wall Location on Strengthening Weak RC Frames(SHARIF UNIV TECH, 2010) Kaltakcı, M. Y.; Arslan, M. H.; Yavuz, G.Hundreds of thousands of Reinforced Concrete (RC) buildings have been either seriously damaged or have completely collapsed due to major earthquakes in recent years in Turkey, therefore, the construction of RC buildings gained momentum by the aid of scientific studies on strengthening. As well as mentioning the importance of the strengthening process using Shear Walls (SW) in RC buildings of poor earthquake performance, an experimental study carried out to analyze the influence of the location of a SW on the existing system was also mentioned in this study. A total of three, two-storey, two-bay RC frames of 1/3 scale were produced for the experiments by expecting them to represent the behavior of the RC frames having weak earthquake strength; two of which were strengthened with SWs. The main aim of this study is to compare the effectiveness of internal and external SW locations on strengthened weak, RC frame earthquake behavior. The strength, stiffness and ductility of the tested frames were compared within the light of numerical results obtained from the experiments. In the study, an overall comparison of strengthening methods was made in terms of applicability, usability and cost.Öğe The effects of steel fibre reinforced concrete on system ductility(CONSEJO SUPERIOR INVESTIGACIONES CIENTIFICAS-CSIC, 2007) Kaltakci, M. Y.; Arslan, M. H.; Yilmaz, U. S.Steel fibre-reinforced concrete is being used extensively today in both field applications and experimental studies on concrete strength and ductility. The state of passive confinement generated by the fibre delays cracking and enhances ductility. The present paper reports on both experimental and analytical studies. In the former, a series of 16 steel-fibre reinforced concrete prismatic specimens were subjected to axial loads and the respective axial load-unit strain diagrams were subsequently plotted to determine the effect of steel fibres on reinforced concrete column ductility. Secondly, an analytical study was run to determine the additional ductility accruing to a frame system when steel fibres are included in the concrete. Analytical models were generated for 16 two-storey, single-span reinforced concrete frames. The columns in these frames were designed to the same characteristics as the specimens used in the experimental tests. Non-linear static (pushover) analyses were performed for each frame to obtain load-displacement curves and determine the effect of steel fibres on reinforced concrete column ductility.Öğe An Experimental Investigation for External RC Shear Wall Applications(Copernicus Gesellschaft Mbh, 2010) Kaltakcı, M. Y.; Öztürk, M.; Arslan, M. H.The strength and rigidity of most reinforced concrete (RC) buildings in Turkey, which are frequently hit by destructive earthquakes, is not at a sufficient level. Therefore, the result of earthquakes is a significant loss of life and property. The strengthening method most commonly preferred for these type of RC buildings is the application of RC in-filled walls (shear walls) in the frame openings of the building. However, since the whole building has to be emptied and additional heavy costs arise during this type of strengthening, users prefer not to strengthen their buildings despite the heavy risk they are exposed to. Therefore, it is necessary to develop easier-to-apply and more effective methods for the rapid strengthening of housing and the heavily-used public buildings which cannot be emptied during the strengthening process (such as hospitals and schools). This study empirically analyses the different methods of a new system which can meet this need. In this new system, named "external shear wall application", RC shear walls are applied on the external surface of the building, along the frame plane rather than in the building. To this end, 7 test samples in 1/2 and 1/3 geometrical scale were designed to analyse the efficiency of the strengthening technique where the shear wall leans on the frame from outside of the building (external shear wall application) and of the strengthening technique where a specific space is left between the frame and the external shear wall by using a coupling beam to connect elements (application of external shear wall with coupling beam). Test results showed that the maximum lateral load capacity, initial rigidity and energy dissipation behaviours of the samples strengthened with external shear wall were much better than those of the bare frames.Öğe GENETIC PROGRAMMING BASED MODELING OF SHEAR CAPACITY OF COMPOSITE BEAMS WITH PROFILED STEEL SHEETING(HONG KONG INST STEEL CONSTRUCTION, 2011) Koroglu, M. A.; Koken, A.; Arslan, M. H.; Cevik, A.This study investigates the availability of Genetic Programming (GP) for modeling the ultimate shear capacity of composite beams with profiled steel sheeting for the first time in literature. Experimental data involving push-out test specimens of 46 composite beams from an existing database in the literature were used to develop GP model. The input parameters affecting the shear capacity were selected as stud position (strong and weak), sheeting type (width of rib of the profiled steel sheeting, depth of the rib), stud dimensions (height and diameter), slab dimensions (width, depth and height), reinforcement in the slab and concrete compression strength. Moreover, a short review of well-known building codes regarding ultimate shear capacity of composite beams is presented. The accuracy of the codes in predicting the ultimate shear capacity of composite beams was also compared with the proposed GP model with comparable way by using same test data. The study concludes that the proposed GP model predicts the ultimate shear capacity of composite beams by far more accurate than building codes.Öğe An investigation on failed or damaged reinforced concrete structures under their own-weight in Turkey(PERGAMON-ELSEVIER SCIENCE LTD, 2007) Kaltakci, M. Y.; Arslan, M. H.; Korkmaz, H. H.; Ozturk, M.In Turkey, more than 90% of building stock consists of reinforced concrete buildings. The majority of Turkey's urban population lives in multi-story apartment blocks constructed with reinforced concrete. In addition to reinforced concrete structure damages caused from especially last decade's earthquakes, there were built structures most of which are unable to carry their own-weight and are not appropriate to engineering and design criteria because of lack of interest, ignorance, lack of inspection and supervision in Turkey. Up to now, even though there are many examples, Turkey has faced two painful experiences in Diyarbakir Hicret Apartment totally collapsed in 1983 and caused significant casualties (93 dead) and in Konya Zumrut Apartment in 2004 (92 dead). The casualties in these phenomenons were more than some big earthquakes. The most significant disadvantage of reinforced concrete buildings is that after producing RC members abolishing detailing defaults cannot be possible. Except for structural damages caused from last big earthquakes, the existence of some RC buildings damaged due to their own-weight and static loading rises a necessity of control and rehabilitation of RC buildings. In the study, first of all, there is mentioned about the causes of structural damages like not obeying the standard criteria, workmanship faults, over design loads (change in the utilization purpose of the building), insufficient material quality and false revisions applied on the construction by the users. The effect of not considering the significant and fundamental criteria existing especially in TEC-98 and TBC-500-2000 on system behavior is examined. Afterwards, giving examples for reinforced concrete structures failed in a 10-year period of time only under its dead load and caused serious life and possession losses, various analyses and experimental studies related with those structures is presented. The samplings will be classified according to the locations of the damages occurred in load-bearing system members. Finally, at the end of the study, damage formation causes and necessary precautions will be specified according to the results obtained from the analytical and experimental data. (C) 2006 Elsevier Ltd. All rights reserved.Öğe Neural network prediction of the ultimate capacity of shear stud connectors on composite beams with profiled steel sheeting(ELSEVIER SCIENCE BV, 2013) Koroglu, M. A.; Koken, A.; Arslan, M. H.; Cevik, A.In this paper, the efficiency of different Artificial Neural Networks (ANNs) in predicting the ultimate shear capacity of shear stud connectors is explored. Experimental data involving push-out test specimens of 118 composite beams from an existing database in the literature were used to develop the ANN model. The input parameters affecting the shear capacity were selected as sheeting, stud dimensions, slab dimensions, reinforcement in the slab and concrete compression strength. Each parameter was arranged in an input vector and a corresponding output vector, which includes the ultimate shear capacity of composite beams. For the experimental test results, the ANN models were trained and tested using three layered back-propagation methods. The prediction performance of the ANN was obtained. In addition to these, the paper presents a short review of the codes in relation to the design of composite beams. The accuracy of the codes in predicting the ultimate shear capacity of composite beams was also examined in a comparable way using the same test data. At the end of the study, the effect of all parameters is also discussed. The study concludes that all ANN models predict the ultimate shear capacity of beams better than codes. (C) 2013 Sharif University of Technology. All rights reserved.Öğe Neuro-Fuzzy Modeling of Torsional Strength of Rc Beams(Techno-Press, 2012) Çevik, A.; Arslan, M. H.; Saraçoğlu, R.This paper presents Neuro-Fuzzy (NF) based empirical modelling of torsional strength of RC beams for the first time in literature. The proposed model is based on fuzzy rules. The experimental database used for NF modelling is collected from the literature consisting of 76 RC beam tests. The input variables in the developed rule based on NF model are cross-sectional area of beams, dimensions of closed stirrups, spacing of stirrups, cross-sectional area of one-leg of closed stirrup, yield strength of stirrup and longitudinal reinforcement, steel ratio of stirrups, steel ratio of longitudinal reinforcement and concrete compressive strength. According to the selected variables, the formulated NFs were trained by using 60 of the 76 sample beams. Then, the method was tested with the other 16 sample beams. The accuracy rates were found to be about 96% for total set. The performance of accuracy of proposed NF model is furthermore compared with existing design codes by using the same database and found to be by far more accurate. The use of NF provided an alternative way for estimating the torsional strength of RC beams. The outcomes of this study are quite satisfactory which may serve NF approach to be widely used in further applications in the field of reinforced concrete structures.Öğe A New Application Area of ANN and ANFIS: Determination of Earthquake Load Reduction Factor of Prefabricated Industrial Buildings(Taylor & Francis Ltd, 2010) Ceylan, M.; Arslan, M. H.; Ceylan, R.; Kaltakcı, M. Y.; Özbay, Y.The earthquake load reduction factor, R, is one of the most important parameters in the design stage of a building. Significant damages and failures were experienced on prefabricated reinforced concrete structures during the last earthquakes in Turkey and the experts agreed that they resulted mainly from the incorrectly selected earthquake load reduction factor, R. In this study, an attempt was made to estimate the R coefficient for prefabricated industrial structures having a single storey, one and two bays, which are commonly constructed for manufacturing andwarehouse operation with variable dimensions. According to the selected variable dimensions, 280 sample (140 samples for one bay (S-1) and 140 samples for two bays (S-2)) frames' load-displacement relations were computed using pushover analysis and the earthquake load reduction factor, R, was calculated for each frame. Then, formulated three-layered artificial neural network methods (ANNs) and adaptive neuro-fuzzy inference system (ANFIS) were trained by using 214 of the 280 sample frames. Then, the methods were tested with the other 66 sample frames. Accuracy rates were found to be about 94% and 96% for ANN and ANFIS, respectively. The use of ANN and ANFIS provided an alternative way for estimating the R and it also showed that ANFIS estimated R more successfully than ANN.Öğe New Trends on Green Buildings: Investigation of the Feasibility of Using Plastic Members in RC Buildings with SWs(IOP PUBLISHING LTD, 2017) Arslan, M. H.; Arslan, H. D.Shear walled (SW) reinforced concrete (RC) buildings are considered to be a type of high seismic safety building. Although this structural system has an important seismic advantage, it also has some disadvantages, especially in acoustic and thermal comfort. In this study, experimental studies have been conducted on RC members produced with plastic material having circular sections to determine structural performance. RC members have been produced with and without 6 cm diameter balls to analyze the structural behaviour under loading and to investigate the thermal performance and sound absorption behaviour of the members. In the study, structural parameters have been determined for RC members such as slabs and SWs produced with and without balls to discover the feasibility of the research and discuss the findings comparatively. The results obtained from the experimental studies show that PB used in RC with suitable positions do not significantly decrease strength but improve the thermal and acoustic features. It has been also seen that using plastic balls reduce the total concrete materials.Öğe NUMERICAL STUDY ON SEISMIC BEHAVIOUR OF PRECAST CONCRETE CONNECTION ZONE(SHIRAZ UNIV, 2009) Arslan, M. H.; Gulay, F. G.Precast industrial plants in Turkey experienced considerable damage during the recent earthquakes in Turkey. The presented paper is based on a parametric study to evaluate the seismic performance of a code-designed moment-transferring scarfed connection that is widely utilized in precast industrial buildings in Turkey. Firstly, the seismic behavior of a typical symmetrically pitched double-bay precast framed system with a scarfed beam to the column connections was investigated. The coefficient of elastic rotational stiffhess, R-theta, and maximum stress values were then obtained by finite element idealization with an approach of a repeated analysis. Finally, a parametric study was carried out for different values of R-theta in order to evaluate the effect of joint elasticity on the behavior of a precast frame under seismic action.Öğe STATISTICAL FEATURE EXTRACTION BASED ON AN ANN APPROACH FOR ESTIMATING THE COMPRESSIVE STRENGTH OF CONCRETE(ACAD SCIENCES CZECH REPUBLIC, INST COMPUTER SCIENCE, 2015) Dogan, G.; Arslan, M. H.; Ceylan, M.Applications of artificial intelligence in engineering disciplines have become widespread and have provided alternative solutions to engineering problems. Image processing technology (IPT) and artificial neural networks (ANNs) are types of artificial intelligence methods. However, IPT and ANN have been used together in extremely few studies. In this study, these two methods were used to determine the compressive strength of concrete, a complex material whose mechanical features are difficult to predict. Sixty cube-shaped specimens were manufactured, and images of specific features of the specimens were taken before they were tested to determine their compressive strengths. An ANN model was constituted as a result of the process of digitizing the images. In this way, the two different artificial intelligence methods were used together to carry out the analysis. The compressive strength values of the concrete obtained via analytical modeling were compared with the test results. The results of the comparison (R-2 = 0.9837-0.9961) indicate that the combination of these two artificial intelligence methods is highly capable of predicting the compressive strengths of the specimens. The model's predictive capability was also evaluated in terms of several statistical parameters using a set of statistical methods during the digitization of the images constituting the artificial neural network.Öğe What is to be learned from damage and failure of reinforced concrete structures during recent earthquakes in Turkey?(PERGAMON-ELSEVIER SCIENCE LTD, 2007) Arslan, M. H.; Korkmaz, H. H.In Turkey, generally, building stock is formed from reinforced concrete structures and during last earthquakes, a large number of these buildings in the epicenter regions were collapsed leading to widespread destruction and loss of life. In this paper, the performance of reinforced concrete buildings during recent earthquakes in Turkey is discussed. The objective of this paper is to provide a brief overview of damage as observed following the earthquakes. The failure modes consist of foundation failures, soft stories, strong beams and weak columns, lack of column confinement, poor detailing practice and non-structural damages. Observations from the earthquake damages are discussed and compared with TEC-98 (Turkish Earthquake Code) and TBC-500-2000 (Turkish Building Code) requirements. Measurements of some damaged reinforced concrete member examples are given and important general lessons learned from these earthquakes are formulated. Finally, a short overview of the emergency management measures taken is also presented. (C) 2006 Elsevier Ltd. All rights reserved.
