University of Tabriz Journal of Civil and Environmental Engineering 2008-7918 46 83 2016 08 22 Estimation of Bridge Pier Scour Using Statistical Methods and Intelligent Algorithms Estimation of Bridge Pier Scour Using Statistical Methods and Intelligent Algorithms 1 13 5185 FA Seyed Morteza Seyedian Faculty of Agriculture, Gonbad Kavoos University Abolhasan Fathabadi Estimation of Bridge Pier Scour Using Statistical Methods and Intelligent Algorithms Journal Article 2016 09 18 When a stream is partially obstructed by a bridge pier, the flow pattern around the pier is significantly changed. Changes in flow pattern are the cause scour around piers. Bridge pier scouring estimates, is an important parameter in the design of bridges because inattention to it may cause damage or reduce the life of the bridge [1-4]. The safe and economical design of bridge piers requires accurate prediction of the maximum scour depth around their foundations [5]. Mathematical Principles of SVM is based Russian mathematician researches [6]. Ghazanfari Hashemi and Etemad Shahidi had predicted bridge pier scour using SVM method in a laboratory model. They showed that this method is more accurate than empirical relationship. Although extensive studies have been conducted on the pier scour, but a valid relationship does not exist that gives satisfactory results in different conditions [5]. Bates and Granger is one of the first research works in the field of hybrid approach [7]. Shamseldin et al. was used combination methods such as simple average, weighted average and neural network to predict floods [8]. Studying literature reveals that there is a lack of reliable formulas for prediction of the scour depth to cover different condition. The aim of this study is combination of the various pier scour relationships to predict the scour depth using conventional and intelligent (SVM) methods and combination of effective parameters of this phenomenon. When a stream is partially obstructed by a bridge pier, the flow pattern around the pier is significantly changed. Changes in flow pattern are the cause scour around piers. Bridge pier scouring estimates, is an important parameter in the design of bridges because inattention to it may cause damage or reduce the life of the bridge [1-4]. The safe and economical design of bridge piers requires accurate prediction of the maximum scour depth around their foundations [5]. Mathematical Principles of SVM is based Russian mathematician researches [6]. Ghazanfari Hashemi and Etemad Shahidi had predicted bridge pier scour using SVM method in a laboratory model. They showed that this method is more accurate than empirical relationship. Although extensive studies have been conducted on the pier scour, but a valid relationship does not exist that gives satisfactory results in different conditions [5]. Bates and Granger is one of the first research works in the field of hybrid approach [7]. Shamseldin et al. was used combination methods such as simple average, weighted average and neural network to predict floods [8]. Studying literature reveals that there is a lack of reliable formulas for prediction of the scour depth to cover different condition. The aim of this study is combination of the various pier scour relationships to predict the scour depth using conventional and intelligent (SVM) methods and combination of effective parameters of this phenomenon.

https://ceej.tabrizu.ac.ir/article_5185_3caf9c9616033ec73bd7065ec98fd82b.pdf

University of Tabriz Journal of Civil and Environmental Engineering 2008-7918 46 83 2016 08 22 Numerical Study on the Effects of the Floodplain Width on Flow Field and Interaction between the Main Channel and Floodplains in Prismatic Compound Channels Numerical Study on the Effects of the Floodplain Width on Flow Field and Interaction between the Main Channel and Floodplains in Prismatic Compound Channels 15 24 5186 FA Alireza Safarzadeh Civil Engineering Department, Faculty of Engineering, Bu-Ali Sina University Bahram Rezaei Civil Engineering Department, Faculty of Engineering, Bu-Ali Sina University Journal Article 2016 09 18 Prediction of flow field in compound channel is an important task for hydraulic researches because of the three dimensional nature of the flow. In compound channels with prismatic floodplains, the main feature consists of the interaction effect between the fast moving flow in the main channel and the slow moving flow on the floodplains. This difference creates a high shear layer at the interface between the main channel and floodplains, leading to the generation of the large scale vortices with vertical axes, as well as the helical secondary with longitudinal axes, as shown by Sellin [1], Tominaga and Nezu [2], Ikeda [3], Bousmar [4] and Rezaei [5]. Prediction of flow field in compound channel is an important task for hydraulic researches because of the three dimensional nature of the flow. In compound channels with prismatic floodplains, the main feature consists of the interaction effect between the fast moving flow in the main channel and the slow moving flow on the floodplains. This difference creates a high shear layer at the interface between the main channel and floodplains, leading to the generation of the large scale vortices with vertical axes, as well as the helical secondary with longitudinal axes, as shown by Sellin [1], Tominaga and Nezu [2], Ikeda [3], Bousmar [4] and Rezaei [5].

https://ceej.tabrizu.ac.ir/article_5186_c05ff8b89d5fa6860f6d4b1e1c26723e.pdf

University of Tabriz Journal of Civil and Environmental Engineering 2008-7918 46 83 2016 08 22 Utilizing Pretension SMAs with Memory Effect Characteristics in Concrete Structure Utilizing Pretension SMAs with Memory Effect Characteristics in Concrete Structure 25 33 5187 FA Mehdi Ghassemieh School of Civil Engineering, University of Tehran Maryam Saberdel Sadeh School of Civil Engineering, University of Tehran Mahnaz Mostafazadeh School of Civil Engineering, University of Tehran Journal Article 2016 09 18 Shape Memory Alloys (SMA) are smart and novel materials that exhibit variable stiffness and strength associated with their different polycrystalline phases. The Shape Memory Effect (SME) and Superelastic Effect (SE) are two distinct properties that make SMA a smart material. Shape memory effect (free recovery effect) means that a large (pseudo-) plastic deformation can be reversed by heating. If the going back is prevented by, e.g., concrete, a stress in the SMA results (constrained recovery effect) [1]. A Superelastic SMA can restore its initial shape spontaneously even from its inelastic range upon unloading. The specific objective of this study is to investigate the effect of ordinary and pretension SMAs with memory effect behavior in concrete shear walls separately. For this purpose, we analyzed concrete shear walls with different percent of SMAs and steels under monotonic loading in ABAQUS Finite element. Two different concrete shear walls, one reinforced with ordinary SMA together with steel rebars and the other with pretension SMA with steel rebars, have been analyzed. The seismic behavior of the two concrete structure models has been compared in terms of their load against displacement. Shape Memory Alloys (SMA) are smart and novel materials that exhibit variable stiffness and strength associated with their different polycrystalline phases. The Shape Memory Effect (SME) and Superelastic Effect (SE) are two distinct properties that make SMA a smart material. Shape memory effect (free recovery effect) means that a large (pseudo-) plastic deformation can be reversed by heating. If the going back is prevented by, e.g., concrete, a stress in the SMA results (constrained recovery effect) [1]. A Superelastic SMA can restore its initial shape spontaneously even from its inelastic range upon unloading. The specific objective of this study is to investigate the effect of ordinary and pretension SMAs with memory effect behavior in concrete shear walls separately. For this purpose, we analyzed concrete shear walls with different percent of SMAs and steels under monotonic loading in ABAQUS Finite element. Two different concrete shear walls, one reinforced with ordinary SMA together with steel rebars and the other with pretension SMA with steel rebars, have been analyzed. The seismic behavior of the two concrete structure models has been compared in terms of their load against displacement.

https://ceej.tabrizu.ac.ir/article_5187_fb886702aacaf63658923f97c572f3e4.pdf

University of Tabriz Journal of Civil and Environmental Engineering 2008-7918 46 83 2016 08 22 The In Situ Strength Assessment of Polymer Self Compacting Concrete in Rc Beams The In Situ Strength Assessment of Polymer Self Compacting Concrete in Rc Beams 35 46 5188 FA Rahmat Madandoust Faculty of Civil Engineering, University of Guilan Asghar Vatani Oskouei Faculty of Civil Engineering, Shahid Rajaee Teacher training University Milad Rajabi Jourshari Takestan Islamic Azad University Journal Article 2016 09 18 Wide attempts have been performed to quantitative and qualitative control on concrete strength in structures and different methods have been innovated to estimate the in situ concrete compressive strength. On the basis of these methods, it can be divided into two groups consisting non-destructive and semi-destructive methods. To provide a suitable compaction, decrease on segregation and bleeding and facilitating on placement of concrete especially in sections with massive reinforcement, self-compacting concrete has been developed. In the research by Zhu et al. [1] in 2001, self-compacting concrete strength along length of beams and height of columns was investigated using core, pull out and Schmitt hammer tests and the results on uniformity showed similar pattern on variations. Also the results indicated that concrete strength variations along height of columns and length of beams for self-compacting concrete are slightly lower than normal concrete. Wide attempts have been performed to quantitative and qualitative control on concrete strength in structures and different methods have been innovated to estimate the in situ concrete compressive strength. On the basis of these methods, it can be divided into two groups consisting non-destructive and semi-destructive methods. To provide a suitable compaction, decrease on segregation and bleeding and facilitating on placement of concrete especially in sections with massive reinforcement, self-compacting concrete has been developed. In the research by Zhu et al. [1] in 2001, self-compacting concrete strength along length of beams and height of columns was investigated using core, pull out and Schmitt hammer tests and the results on uniformity showed similar pattern on variations. Also the results indicated that concrete strength variations along height of columns and length of beams for self-compacting concrete are slightly lower than normal concrete.

https://ceej.tabrizu.ac.ir/article_5188_9f3cb6d35af0f8ee5a0b3b3098d67ef1.pdf

University of Tabriz Journal of Civil and Environmental Engineering 2008-7918 46 83 2016 08 22 The Effect of Active Confinement and shear key Elements on the Flexural Behavior of Concrete Filled Steel Tube (CFST) The Effect of Active Confinement and shear key Elements on the Flexural Behavior of Concrete Filled Steel Tube (CFST) 47 60 5194 FA Morteza Naghipour Civil Engineering Faculty, Babol Noshirvani University of Technology Marzieh Nemati Civil Engineering Faculty, Babol Noshirvani University of Technology Javad Jalali Civil Engineering Faculty, Babol Noshirvani University of Technology Mahdi Nematzadeh Faculty of Engineering and Technology, University of Mazandaran Journal Article 2016 09 19 In recent years, extensive research has been carried out on concrete filled steel tubes (CFST). The subsequent results indicate the superiority of concrete filled steel tubes in relation to reinforced concrete or steel members.This section type offers multiple structural advantages such as increasing the loading capacity, higher value of absorbed energy, ductile deformation, seismic resistance, and sufficient damping. Applying the initial pressure on the fresh concrete and removing the excess water increased the compressive strength and Elastic modulus of concrete [1-3]. The effective factors on the flexural behavior of CFST beams was investigated and was concluded that the active confinement has no effect on the sample's failure mode [4]. However, active confinement leads to reduction in the extent and intensity of concrete crushing in the compressive zone as well as reduction in the extent of the cracked region and crack depth in the sample's tensile zone. Furthermore, the results showed that the best performance for active confinement of the concrete core is obtained for a section with D/t=30 and low compressive strength of the concrete core. In this section, the value of absorbed energy and the flexural strength increase simultaneously. In recent years, extensive research has been carried out on concrete filled steel tubes (CFST). The subsequent results indicate the superiority of concrete filled steel tubes in relation to reinforced concrete or steel members.This section type offers multiple structural advantages such as increasing the loading capacity, higher value of absorbed energy, ductile deformation, seismic resistance, and sufficient damping. Applying the initial pressure on the fresh concrete and removing the excess water increased the compressive strength and Elastic modulus of concrete [1-3]. The effective factors on the flexural behavior of CFST beams was investigated and was concluded that the active confinement has no effect on the sample's failure mode [4]. However, active confinement leads to reduction in the extent and intensity of concrete crushing in the compressive zone as well as reduction in the extent of the cracked region and crack depth in the sample's tensile zone. Furthermore, the results showed that the best performance for active confinement of the concrete core is obtained for a section with D/t=30 and low compressive strength of the concrete core. In this section, the value of absorbed energy and the flexural strength increase simultaneously.

https://ceej.tabrizu.ac.ir/article_5194_73da2e17d8913b33166eac562f611b47.pdf

University of Tabriz Journal of Civil and Environmental Engineering 2008-7918 46 83 2016 08 22 Experimental Investigation of Scour Upstream of a Square Orifice under Constant Head Experimental Investigation of Scour Upstream of a Square Orifice under Constant Head 61 71 5190 FA Hassan Vosoughi Faculty of Civil Engineering, Islamic Azad University, Central Tehran branch Hooman Hajikandi Faculty of Civil Engineering, Islamic Azad University, Central Tehran branch Journal Article 2016 09 18 Orifices are historically used in different hydraulic structures for flow regulation and removal of sediments from reservoirs. The performance of orifices in drawdown flushing to increase the lifetime of dams is vital. Anayiotos et al. [1] performed extensive measurements of the velocity contours upstream of an orifice. They have reported that the shape of the velocity contours at the vicinity of the orifice becomes elliptical. Chanson et al. [2] studied the characteristics of the flow in an orifice under unsteady flow condition. Their measurement were done by means of ADV technique. Bryant et al. [3] conducted experiments to study the flow upstream of a small orifice, a large orifice, an orifice near the free surface, and multiple orifices [3]. Physical and numerical studies were conducted to quantify the scour or sediment removal upstream of orifices under a falling head [4]. One of the most important parameters affecting scour characteristics upstream of the orifices is the shape of the orifices. This paper reports the results of experiments carrie out on the mechanism of scour upstream of square orifices. Velocity profiles before and after the scour process are compared to understand the flow behavior associated with the equilibrium scour conditions. Orifices are historically used in different hydraulic structures for flow regulation and removal of sediments from reservoirs. The performance of orifices in drawdown flushing to increase the lifetime of dams is vital. Anayiotos et al. [1] performed extensive measurements of the velocity contours upstream of an orifice. They have reported that the shape of the velocity contours at the vicinity of the orifice becomes elliptical. Chanson et al. [2] studied the characteristics of the flow in an orifice under unsteady flow condition. Their measurement were done by means of ADV technique. Bryant et al. [3] conducted experiments to study the flow upstream of a small orifice, a large orifice, an orifice near the free surface, and multiple orifices [3]. Physical and numerical studies were conducted to quantify the scour or sediment removal upstream of orifices under a falling head [4]. One of the most important parameters affecting scour characteristics upstream of the orifices is the shape of the orifices. This paper reports the results of experiments carrie out on the mechanism of scour upstream of square orifices. Velocity profiles before and after the scour process are compared to understand the flow behavior associated with the equilibrium scour conditions.

https://ceej.tabrizu.ac.ir/article_5190_85bb8a3556f86a4dfa1d8c897488ed5f.pdf

University of Tabriz Journal of Civil and Environmental Engineering 2008-7918 46 83 2016 08 22 Seismic Damage Forecasting for Steel Moment Frames using Neural Networks Seismic Damage Forecasting for Steel Moment Frames using Neural Networks 75 86 5191 FA Hamid Moharrami Department of Civil and Environmental Engineering, Tarbiat Modares University Seyed Hassan Madani Department of Civil and Environmental Engineering, Tarbiat Modares University Journal Article 2016 09 18 In this research a neural network algorithm is used to process information of numerous nonlinear dynamic analyses data so that the damage induced by an earthquake (similar to earthquakes of this study) in a structure can be obtained in an acceptable range of accuracy by spending much less time than the computation time for actual nonlinear analysis of the structure [1]. To this end, about 800 nonlinear dynamic analyses of steel moment frames under Tabas, Chichi and Kobe earthquakes has been conducted spending a very long computation time. Then the damage of structures with five different damage indices has been calculated. To design a neural network 70% of responses were randomly chosen for training data and the remaining 30% were used for the test and verification of the neural network software. The designed neural network is a multiple layer Perceptron network that has a hidden layer and is trained by Error Back-Propagation algorithm. With the aid of this neural network software if a structure (similar in characteristics to the frames of this study) is excited by an earthquake similar to the abovementioned earthquakes, its damage indices with five definitions will be calculated in a few seconds with an acceptable accuracy. In the paper the five damage indices including the damage index that is suggested by the authors are briefly introduced. Finally, the accuracy of the results of neural networks software for the five different damage indices are compared to each other. In this research a neural network algorithm is used to process information of numerous nonlinear dynamic analyses data so that the damage induced by an earthquake (similar to earthquakes of this study) in a structure can be obtained in an acceptable range of accuracy by spending much less time than the computation time for actual nonlinear analysis of the structure [1]. To this end, about 800 nonlinear dynamic analyses of steel moment frames under Tabas, Chichi and Kobe earthquakes has been conducted spending a very long computation time. Then the damage of structures with five different damage indices has been calculated. To design a neural network 70% of responses were randomly chosen for training data and the remaining 30% were used for the test and verification of the neural network software. The designed neural network is a multiple layer Perceptron network that has a hidden layer and is trained by Error Back-Propagation algorithm. With the aid of this neural network software if a structure (similar in characteristics to the frames of this study) is excited by an earthquake similar to the abovementioned earthquakes, its damage indices with five definitions will be calculated in a few seconds with an acceptable accuracy. In the paper the five damage indices including the damage index that is suggested by the authors are briefly introduced. Finally, the accuracy of the results of neural networks software for the five different damage indices are compared to each other.

https://ceej.tabrizu.ac.ir/article_5191_d9f6079fb92e1ffdc10f41c6e9ee5654.pdf

University of Tabriz Journal of Civil and Environmental Engineering 2008-7918 46 83 2016 08 22 Forecasting Concentrations of Gaseous Air Pollutants Using Artificial Neural Networks in Tabriz Forecasting Concentrations of Gaseous Air Pollutants Using Artificial Neural Networks in Tabriz 87 94 5192 FA Nahideh Mohammadi Student Research Committee, Tabriz University of Medical Sciences Khaled Zoroufchi Benis Faculty of Chemical Engineering, Environmental Engineering Research Center, Sahand University of Technology Mohammad Shakerkhatibi Department of Environmental Health Engineering, Tabriz University of Medical Sciences Esmaeil Fatehifar Faculty of Chemical Engineering, Environmental Engineering Research Center, Sahand University of Technology Alireza Behrooz Sarand Department of Chemical Engineering, Urmia University of Technology Amir Mahmoudian Student Research Committee, Tabriz University of Medical Sciences Farid Sheikholeslami Student Research Committee, Tabriz University of Medical Sciences Journal Article 2016 09 18 Today, air pollution is considered as an important and challenging problem in the megacities all over the world. It is usually caused due to industrialization, urbanization, rapid development in traffic and increasing amounts of anthropogenic emissions. Urban air pollution in developing countries has been represented as a growing problem for communities. Reliable forecasting of air pollution would allow taking more efficient countermeasures to prevent air pollution crisis and protect public health. The artificial Neural Network (ANN) has emerged out to be more flexible, less assumption dependent and adaptive methodology to obtain reliable prediction values of air pollutants. ANNs have been shown to be quite powerful in capturing the complex and usually nonlinear relationships between meteorological variables and air pollutant concentrations [1-3]. Today, air pollution is considered as an important and challenging problem in the megacities all over the world. It is usually caused due to industrialization, urbanization, rapid development in traffic and increasing amounts of anthropogenic emissions. Urban air pollution in developing countries has been represented as a growing problem for communities. Reliable forecasting of air pollution would allow taking more efficient countermeasures to prevent air pollution crisis and protect public health. The artificial Neural Network (ANN) has emerged out to be more flexible, less assumption dependent and adaptive methodology to obtain reliable prediction values of air pollutants. ANNs have been shown to be quite powerful in capturing the complex and usually nonlinear relationships between meteorological variables and air pollutant concentrations [1-3].

https://ceej.tabrizu.ac.ir/article_5192_d538da6a41bb48b1b634f4d927cdc03b.pdf

University of Tabriz Journal of Civil and Environmental Engineering 2008-7918 46 83 2016 08 22 Studying the Behavior of Central Gusset Plate Connections on Inverted V-Braces Studying the Behavior of Central Gusset Plate Connections on Inverted V-Braces 95 106 5193 FA Moosa Mazloom Shahid Rajaee Teacher Training University Vahid Salehi Shahid Rajaee Teacher Training University Journal Article 2016 09 18 In this research, the hysteretic behavior of 14 inverted-V braces and their gusset plate connections subjected to inelastic cyclic loading is examined through analytical simulations. It was modeled in ABAQUS software and the analysis type was static nonlinear analysis. Gusset plates with a constant thickness but with different sizes and shapes were used. To verify the correctness of the analysis, hysteretic behavior of gusset plates obtained from analysis was compared with experimental results. This comparison showed the exactness of the modeling. Then 14 samples of more important gusset plates in terms of ductility and strength were compared. The final result is that although stiffener in the gusset plates increase the strength of connections, they reduce ductility; so, numerous and indiscriminate addition of stiffeners in gusset plates are not recommended. In this research, the hysteretic behavior of 14 inverted-V braces and their gusset plate connections subjected to inelastic cyclic loading is examined through analytical simulations. It was modeled in ABAQUS software and the analysis type was static nonlinear analysis. Gusset plates with a constant thickness but with different sizes and shapes were used. To verify the correctness of the analysis, hysteretic behavior of gusset plates obtained from analysis was compared with experimental results. This comparison showed the exactness of the modeling. Then 14 samples of more important gusset plates in terms of ductility and strength were compared. The final result is that although stiffener in the gusset plates increase the strength of connections, they reduce ductility; so, numerous and indiscriminate addition of stiffeners in gusset plates are not recommended.

https://ceej.tabrizu.ac.ir/article_5193_e0f34b08b97eb6a44d375c32138090a5.pdf