Amirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X50420181023Numerical Simulation of the over and through flow Discharge in Broad-Crested Gabion Weirs with side SlopesNumerical Simulation of the over and through flow Discharge in Broad-Crested Gabion Weirs with side Slopes619630196410.22060/ceej.2017.12637.5238FAM.Tavakol-SadrabadiSchool of Water Sciences Engineering, Shahid Chamran University of Ahvaz, Ahvaz, IranM.Fathi-moghaddamSchool of Water Sciences Engineering, Shahid Chamran University of Ahvaz, Ahvaz, IranR.MohammadpourDepartment of Civil Engineering, Islamic Azad University-Estahban Branch, Fars, Iran0000-0002-7940-5101Journal Article20170309<span>During the recent years, Gabion weirs have been taken into consideration due to their compatibility with the environment, positive effect on river’s water quality and their simple design and implementation. In this research, the hydraulic parameters of flow around broad crested gabion weirs (BCGW) with various side slopes are investigated. Overall, a number of 21 models comprising 7 various geometries each with 3 different porosities including (43%, 44%, 46%) and in different discharges were simulated and studied. Results indicated that the discharge coefficient (Cd), through flow discharge and energy dissipation increased by increasing the average diameter of particles. In addition, Increasing the area of the porous media by changing side angles from 0</span><span>ᵒ</span><span> to 60</span><span>ᵒ</span><span> reduces the discharge coefficient and through flow discharge. At final stage, experimental equations are presented using Nonlinear Multivariable regression analysis in order to calculate the discharge coefficient and through flow discharge of these structures.</span><span>During the recent years, Gabion weirs have been taken into consideration due to their compatibility with the environment, positive effect on river’s water quality and their simple design and implementation. In this research, the hydraulic parameters of flow around broad crested gabion weirs (BCGW) with various side slopes are investigated. Overall, a number of 21 models comprising 7 various geometries each with 3 different porosities including (43%, 44%, 46%) and in different discharges were simulated and studied. Results indicated that the discharge coefficient (Cd), through flow discharge and energy dissipation increased by increasing the average diameter of particles. In addition, Increasing the area of the porous media by changing side angles from 0</span><span>ᵒ</span><span> to 60</span><span>ᵒ</span><span> reduces the discharge coefficient and through flow discharge. At final stage, experimental equations are presented using Nonlinear Multivariable regression analysis in order to calculate the discharge coefficient and through flow discharge of these structures.</span>https://ceej.aut.ac.ir/article_1964_a2a4479b61aceb9cc4795e261ec9edc3.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X50420181023Quantitative Model of Optimal Conjunctive use of Mahabad Plain’s Surface and Underground Water ResourcesQuantitative Model of Optimal Conjunctive use of Mahabad Plain’s Surface and Underground Water Resources631640163810.22060/ceej.2017.12739.5266FAE.ValizadeganFaculty of Engineering, Islamic Azad University, Khoy Branch, Khoy, IranS.YazdanpanahFaculty of Engineering, Islamic Azad University, Mragheh Branch, Maragheh, IranJournal Article20170416<span>According to available information and the population growth as well as the ever-increasing development of agriculture, there is an upward trend in withdrawals from surface water and groundwater resources in different regions of the country such as Mahabad to provide water demand for the region. The optimal conjunctive use of surface and groundwater resources is one way to providing the water demands in crisis and drought situations. In this study, a management model based on effective techniques of optimization and simulation has been developed to solve the optimization problem. Variation of groundwater table level in Mahabad plain was simulated using GMS software initially. Then based on the results of this simulation, artificial neural network was trained to use in simulate- optimization system. Genetic algorithm was used to solve the optimization problem. The results indicate that this model is powerful and effective for solving large-scale problems and optimal conjunctive use of surface water and groundwater resources of Mahabad. Based on the results of the research and running of the model, the approximate share of water supply of water resources, is respectively 13.5 and 86.5 percent of surface water and groundwater resources.</span><span>According to available information and the population growth as well as the ever-increasing development of agriculture, there is an upward trend in withdrawals from surface water and groundwater resources in different regions of the country such as Mahabad to provide water demand for the region. The optimal conjunctive use of surface and groundwater resources is one way to providing the water demands in crisis and drought situations. In this study, a management model based on effective techniques of optimization and simulation has been developed to solve the optimization problem. Variation of groundwater table level in Mahabad plain was simulated using GMS software initially. Then based on the results of this simulation, artificial neural network was trained to use in simulate- optimization system. Genetic algorithm was used to solve the optimization problem. The results indicate that this model is powerful and effective for solving large-scale problems and optimal conjunctive use of surface water and groundwater resources of Mahabad. Based on the results of the research and running of the model, the approximate share of water supply of water resources, is respectively 13.5 and 86.5 percent of surface water and groundwater resources.</span>https://ceej.aut.ac.ir/article_1638_a0c2edf862cc43f09d3986afc8a423f1.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X50420181023Study of the Phosphorus Losses from Different Watersheds in Guilan ProvinceStudy of the Phosphorus Losses from Different Watersheds in Guilan Province641654265810.22060/ceej.2017.12803.5274FAH.AsadiSoil Science Department, University of Tehran, Tehran, IranV.LatifiSoil Science Department, University of Guilan, Guilan, IranE.EbrahimiSoil Science Department, University of Guilan, Guilan, IranJournal Article20170422<span>Phosphorus is one of the essential nutrients for plants which is major pollutants originating from non-point sources such as urban run-off, residential, industrial and agricultural areas. Run-off movement and erosion result in phosphorus loss from watershed and entering the water body. The aim of this study was to investigate the phosphorus release from sub-watersheds under different land-use in Guilan province. These sub-watersheds included Divshel, Komsar, Jokolbandan, Sangar and Saravan. Samples were taken monthly from the run-off of these sub-watersheds during one year. Then, some properties of run-off including electrical conductivity and acidity of run-off, total solids, total suspended solids and total dissolved solids were measured by weighing method; moreover, three types of phosphorus, total phosphorus, water-soluble phosphorus and particulate phosphorus were determined as well. The results showed that the highest loss of total phosphorus was relevant to Sangar with forest and agricultural land uses in February (0.228 mg/l). Phosphorus variations in these sub-watersheds were dependent on the amount of monthly precipitation and phosphorus loss was increased with augmenting rainfall. The maximum mean of water-soluble phosphorus losses were related to Jokolbandan with the dominant land use of forest (0.36 mg/l) and Saravan with land uses of forest and industrial activities (0.33 mg/l), respectively. Furthermore, the highest loss of particulate phosphorus was from Sangar in April (0.192 mg/l). The level of phosphorous losses from the studied sub-watersheds was high enough to result in eutrophication of water bodies and consequently water quality decline.</span><span>Phosphorus is one of the essential nutrients for plants which is major pollutants originating from non-point sources such as urban run-off, residential, industrial and agricultural areas. Run-off movement and erosion result in phosphorus loss from watershed and entering the water body. The aim of this study was to investigate the phosphorus release from sub-watersheds under different land-use in Guilan province. These sub-watersheds included Divshel, Komsar, Jokolbandan, Sangar and Saravan. Samples were taken monthly from the run-off of these sub-watersheds during one year. Then, some properties of run-off including electrical conductivity and acidity of run-off, total solids, total suspended solids and total dissolved solids were measured by weighing method; moreover, three types of phosphorus, total phosphorus, water-soluble phosphorus and particulate phosphorus were determined as well. The results showed that the highest loss of total phosphorus was relevant to Sangar with forest and agricultural land uses in February (0.228 mg/l). Phosphorus variations in these sub-watersheds were dependent on the amount of monthly precipitation and phosphorus loss was increased with augmenting rainfall. The maximum mean of water-soluble phosphorus losses were related to Jokolbandan with the dominant land use of forest (0.36 mg/l) and Saravan with land uses of forest and industrial activities (0.33 mg/l), respectively. Furthermore, the highest loss of particulate phosphorus was from Sangar in April (0.192 mg/l). The level of phosphorous losses from the studied sub-watersheds was high enough to result in eutrophication of water bodies and consequently water quality decline.</span>https://ceej.aut.ac.ir/article_2658_4fb8f2ae472ac992f83d832bc76748ca.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X50420181023Effect of Netted Collar on Maximum Local Scouring Depth of Cubic Bridge Pile GroupsEffect of Netted Collar on Maximum Local Scouring Depth of Cubic Bridge Pile Groups655664266610.22060/ceej.2017.2666FAN.BahramiShahid Chamran University of Ahvaz, Faculty of Water Sciences Engineering, Ahvaz, IranM.GhomeshiShahid Chamran University of Ahvaz, Faculty of Water Sciences Engineering, Ahvaz, IranJournal Article20170607Every year in various parts of the world a number of bridges are destroyed by flood just when we need them. Much of this destruction are due to scour around their piers. Erosion and the movement of the bed material due to the water flow say scouring. During this process, a hole is formed around piers that its depth to reach the depth of equilibrium, increases regularly. In this study a flume is used with 6 m length and width of 73 cm and bed slope near to the zero in the Hydraulic Laboratory of Shahid Chamran University of Ahvaz. In order to reduce the scour around the pile groups, a thin plate so-call “collar” was installed around the middle the pile group. The collars were simple and netted with opening of 30, 50 and 70 Percentage and were installed in three levels including: on the bed, 0.5D and 1D above the bed. The experiments were conducted under the conditions of clear water and three Froude Number equal to 0.12, 0.14 and 0.16 and the results were compared with the case of without collar mode. The results showed that simple collar installed on the bed and 70% netted collar placed at 0.5D level from the bed were reduced scour equal to 95% and 86%, respectively in compare with the non-collar.Every year in various parts of the world a number of bridges are destroyed by flood just when we need them. Much of this destruction are due to scour around their piers. Erosion and the movement of the bed material due to the water flow say scouring. During this process, a hole is formed around piers that its depth to reach the depth of equilibrium, increases regularly. In this study a flume is used with 6 m length and width of 73 cm and bed slope near to the zero in the Hydraulic Laboratory of Shahid Chamran University of Ahvaz. In order to reduce the scour around the pile groups, a thin plate so-call “collar” was installed around the middle the pile group. The collars were simple and netted with opening of 30, 50 and 70 Percentage and were installed in three levels including: on the bed, 0.5D and 1D above the bed. The experiments were conducted under the conditions of clear water and three Froude Number equal to 0.12, 0.14 and 0.16 and the results were compared with the case of without collar mode. The results showed that simple collar installed on the bed and 70% netted collar placed at 0.5D level from the bed were reduced scour equal to 95% and 86%, respectively in compare with the non-collar.https://ceej.aut.ac.ir/article_2666_155ffa8ff7b5c8de8682e1614c6dedde.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X50420181023The Effect of Connection Conditions on the Cyclic Behavior of U-shaped Metallic Yielding DampersThe Effect of Connection Conditions on the Cyclic Behavior of U-shaped Metallic Yielding Dampers665672195010.22060/ceej.2017.12536.5225FAJ.RoshaniFaculty of Civil Engineering, University of Tabriz, Eastern Azerbaijan, IranS.BagheriFaculty of Civil Engineering, University of Tabriz, Eastern Azerbaijan, Iran0000-0001-6059-5577Journal Article20170212The metallic dampers are one of the most widely used energy dissipation devices that can be used in building and non-building structures such as bridges. U-shaped metallic strips are among these tools. The effects of some parameters such as the number and arrangement of connection bolts on the cyclic behavior and energy dissipation capability during earthquake events will be evaluated in this study using nonlinear finite element method. According to the numerical results, simulation of the bolts, and their number and arrangements have significant effects in the resultant behavior in the transverse cyclic loading. <br /> The metallic dampers are one of the most widely used energy dissipation devices that can be used in building and non-building structures such as bridges. U-shaped metallic strips are among these tools. The effects of some parameters such as the number and arrangement of connection bolts on the cyclic behavior and energy dissipation capability during earthquake events will be evaluated in this study using nonlinear finite element method. According to the numerical results, simulation of the bolts, and their number and arrangements have significant effects in the resultant behavior in the transverse cyclic loading. <br /> https://ceej.aut.ac.ir/article_1950_518a32c26d0530e66fa5cec5c798366c.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X50420181023Studying the Effect of the Amount of Source Materials and Water to Binder Ratio on Chloride Ions Ingress in Alkali-Activated Slag ConcretesStudying the Effect of the Amount of Source Materials and Water to Binder Ratio on Chloride Ions Ingress in Alkali-Activated Slag Concretes67368469510.22060/ceej.2016.695FAA.Ramezanianpor1 Faculty of Civil and Environmental Engineering, Amirkabir University, Tehran, IranF.Bahman ZadehFaculty of Civil and Environmental Engineering, Amirkabir University, Tehran, IranA.ZolfagharnasabFaculty of Civil and Environmental Engineering, Amirkabir University, Tehran, IranA.MRamezanianpourFaculty of Civil Engineering, University of Tehran, Tehran, IranJournal Article20160221<span>Due to the high amount of CO</span><span class="A7"><span>2 </span></span><span>emission through the production of cement and great energy consumption in the cement industry, one of the most important issues in concrete technology is to find out an appropriate replacement for Portland cement. Alkali activated materials are the new approach for solving this problem. In fact, alkali activated concrete consists of an inorganic structure containing two parts: source material and alkaline activator liquid. In this study, the effect of the amount of source material and water to binder ratio on chloride ions ingress was evaluated. For this purpose, 5 mix designs were used to make alkali activated slag (AAS) concretes and for activating slag, 6 molar potassium hydroxide and sodium silicate solutions (wt. ratio: Na</span><span class="A7"><span>2</span></span><span>O/SiO</span><span class="A7"><span>2 </span></span><span>= 2.33) were employed as alkaline activator liquid. Additionally, one mix design was dedicated to ordinary Portland cement (OPC) concrete for the sake of comparison. </span><span>The properties of AAS concretes were examined by means of slump loss test, measurement of compressive strength at the ages of 1, 7, 28, 90 and 180 days and also capillary water absorption test at 7, 28 and 90 days. Furthermore, chloride ions penetration was measured through electrical resistivity test, rapid chloride migration test (RCMT) and resistance against chloride ions diffusion test according to NT Build 443. The results indicated that the performance of water to binder ratio and also the amounts of source material were comparable to that of ordinary Portland cement (OPC) concretes. Additionally, alkali activated slag (AAS) concretes had higher compressive strength and also superior durability against chloride ions penetration compared to OPC concretes.</span><span>Due to the high amount of CO</span><span class="A7"><span>2 </span></span><span>emission through the production of cement and great energy consumption in the cement industry, one of the most important issues in concrete technology is to find out an appropriate replacement for Portland cement. Alkali activated materials are the new approach for solving this problem. In fact, alkali activated concrete consists of an inorganic structure containing two parts: source material and alkaline activator liquid. In this study, the effect of the amount of source material and water to binder ratio on chloride ions ingress was evaluated. For this purpose, 5 mix designs were used to make alkali activated slag (AAS) concretes and for activating slag, 6 molar potassium hydroxide and sodium silicate solutions (wt. ratio: Na</span><span class="A7"><span>2</span></span><span>O/SiO</span><span class="A7"><span>2 </span></span><span>= 2.33) were employed as alkaline activator liquid. Additionally, one mix design was dedicated to ordinary Portland cement (OPC) concrete for the sake of comparison. </span><span>The properties of AAS concretes were examined by means of slump loss test, measurement of compressive strength at the ages of 1, 7, 28, 90 and 180 days and also capillary water absorption test at 7, 28 and 90 days. Furthermore, chloride ions penetration was measured through electrical resistivity test, rapid chloride migration test (RCMT) and resistance against chloride ions diffusion test according to NT Build 443. The results indicated that the performance of water to binder ratio and also the amounts of source material were comparable to that of ordinary Portland cement (OPC) concretes. Additionally, alkali activated slag (AAS) concretes had higher compressive strength and also superior durability against chloride ions penetration compared to OPC concretes.</span>https://ceej.aut.ac.ir/article_695_ebb3c068b2f05b2067c843f70870b8b0.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X50420181023Simulating Freight-Wagon Grouping and Train Scheduling Policies for Iran Rail Network: A Study on Exhausted Emissions of Diesel LocomotiveSimulating Freight-Wagon Grouping and Train Scheduling Policies for Iran Rail Network: A Study on Exhausted Emissions of Diesel Locomotive685696267910.22060/ceej.2017.12657.5243FAA.MoeinaddiniDepartment of Civil & Environmental Engineering, Amirkabir University of Technology, Tehran, IranM.HabibianDepartment of Civil & Environmental Engineering, Amirkabir University of Technology, Tehran, IranJournal Article20170312Because of the important role of Iran railway network in in-land freight transportation, appropriate freight-wagon grouping and train scheduling can significantly reduce the amount of emissions as well as fuel consumption. This paper evaluates the impact of different freight-wagon grouping and different train scheduling policies by using a simulation model of moving trains on the Iran rail network. Based on three related issues including train scheduling, wagon grouping and train formation, eight scenarios have been designed in addition to the do-nothing. Each scenario investigates the demand of freight transportation of the Iran rail network to determine locomotive emissions consist of CO2, SO2, PM, NOx, CO and HC. This study shows that simultaneous implementation of “un-necessary grouping” and “flexible scheduling” policies can lead to the lowest amount of total emissions.Because of the important role of Iran railway network in in-land freight transportation, appropriate freight-wagon grouping and train scheduling can significantly reduce the amount of emissions as well as fuel consumption. This paper evaluates the impact of different freight-wagon grouping and different train scheduling policies by using a simulation model of moving trains on the Iran rail network. Based on three related issues including train scheduling, wagon grouping and train formation, eight scenarios have been designed in addition to the do-nothing. Each scenario investigates the demand of freight transportation of the Iran rail network to determine locomotive emissions consist of CO2, SO2, PM, NOx, CO and HC. This study shows that simultaneous implementation of “un-necessary grouping” and “flexible scheduling” policies can lead to the lowest amount of total emissions.https://ceej.aut.ac.ir/article_2679_1bda20296d7b56c623653678830c08fc.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X50420181023The Effect of Changes in Carbon-Dioxide Concentrations on Corrosion Initiation of Reinforced Concrete StructuresThe Effect of Changes in Carbon-Dioxide Concentrations on Corrosion Initiation of Reinforced Concrete Structures697706115210.22060/ceej.2017.12385.5199FAM.Ghanooni BaghaDepartment of civil Engineering, East Tehran Branch, Islamic Azad University, Tehran, IranM.AShayanfarThe Centre of Excellence for Fundamental Studies in Structural Engineering, Iran University of Science and Technology, Tehran, IranM.RYekke FallahSchool of Civil Engineering, Iran University of Science and Technology, Tehran, IranJournal Article20170109<span>Carbon dioxide and carbonation in concrete structures after several years may leads to corrosion of the reinforcements, and consequently reduces the life of concrete structures. According to reports of Intergovernmental Panel on Climate Change (IPCC), uncertainty to predict the weather conditions is very high. The annual growth rate of carbon dioxide concentrations from 1.4 ppm during the period of 1960 to 2005 has increased to 1.9 ppm during the period of 1995 to 2005. Two predictions of A1F1 and A1B are presented for changes in carbon dioxide concentrations. In A1F1 high economic growth, population growth will continue in the mid-21st century with high speed, and the use of fossil fuels will also continue as before. In A1B, using clean energies is common. In fact, A1F1 and A1B are respectively pessimistic and optimistic predictions for the concentration of carbon dioxide in the environment. According the analysis results base on Monte Carlo simulation, global warming and climate change lead to an increase in average temperature of earth and atmospheric carbon dioxide concentrations, and finally, it can reduce the durability of concrete structures. Also, it was observed that ignoring changes in concentration of carbon dioxide can have a significant effect on the results obtained for carbonation depth. It was also observed that considering each of predictions for changes in carbon dioxide concentrations does not substantially influence the depth of carbonation.</span><span>Carbon dioxide and carbonation in concrete structures after several years may leads to corrosion of the reinforcements, and consequently reduces the life of concrete structures. According to reports of Intergovernmental Panel on Climate Change (IPCC), uncertainty to predict the weather conditions is very high. The annual growth rate of carbon dioxide concentrations from 1.4 ppm during the period of 1960 to 2005 has increased to 1.9 ppm during the period of 1995 to 2005. Two predictions of A1F1 and A1B are presented for changes in carbon dioxide concentrations. In A1F1 high economic growth, population growth will continue in the mid-21st century with high speed, and the use of fossil fuels will also continue as before. In A1B, using clean energies is common. In fact, A1F1 and A1B are respectively pessimistic and optimistic predictions for the concentration of carbon dioxide in the environment. According the analysis results base on Monte Carlo simulation, global warming and climate change lead to an increase in average temperature of earth and atmospheric carbon dioxide concentrations, and finally, it can reduce the durability of concrete structures. Also, it was observed that ignoring changes in concentration of carbon dioxide can have a significant effect on the results obtained for carbonation depth. It was also observed that considering each of predictions for changes in carbon dioxide concentrations does not substantially influence the depth of carbonation.</span>https://ceej.aut.ac.ir/article_1152_16a147bd6b9e021bd757e54fab63e545.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X50420181023An Investigation on the Pozzolanic Reactivity of Different Materials and Their Effects on the Properties of Ultra-high Performance Concrete (UHPC)An Investigation on the Pozzolanic Reactivity of Different Materials and Their Effects on the Properties of Ultra-high Performance Concrete (UHPC)707724267110.22060/ceej.2017.12909.5291FAH.MadaniCivil engineering faculty, Graduate University of Advanced Technology, Kerman, IranA.PourjhanshahiCivil engineering faculty, Graduate University of Advanced Technology, Kerman, IranJournal Article20170524<span>The partial replacement of cement with industrial wastes, especially in the concretes with high volume of cement-based materials such as ultra-high performance concretes (UHPC) may have positive effects on the environment and could lead to improvements in concrete properties. However, the effects of some types of these materials, such as coal waste and copper slag, have not been investigated seriously. In this study, the effects of several cement-based materials with different pozzolanic reactivity from very active (like silica fume) to approximately inactive (like silica powder) have been studied on the UHPC properties. Since the treatment temperature of 70-100 </span><span class="A6"><span>0</span></span><span>C intensifies the possibility of delayed ettringite formation, thermal curing at 60 </span><span class="A6"><span>0</span></span><span>C and 90 </span><span class="A6"><span>0</span></span><span>C have been selected as the treatment temperatures of low and high risk of delayed ettringite formation, furthermore the results have been compared with the standard thermal curing at 20 </span><span class="A6"><span>0</span></span><span>C. An electrical conductivity method has been used to compare the pozzolanic reaction rate of materials. In this study, compressive strengths, modulus of rupture and rapid chloride migration coefficients have been determined and the investigation of microstructure has been carried out using scanning electron microscopy. The obtained results show that use of heat treatment for the mixtures incorporating materials with low pozzolanic reactivity may reduce the strength and durability of ultra-high performance mixtures. The differences between the results obtained from the thermal curing conditions of 60 </span><span class="A6"><span>0</span></span><span>C and 90 </span><span class="A6"><span>0</span></span><span>C were not significant, however use of thermal curing at 90 </span><span class="A6"><span>0</span></span><span>C requires higher energy demand compared with the thermal curing at 60 </span><span class="A6"><span>0</span></span><span>C, moreover higher risk of delayed ettringite formation is expected.</span><span>The partial replacement of cement with industrial wastes, especially in the concretes with high volume of cement-based materials such as ultra-high performance concretes (UHPC) may have positive effects on the environment and could lead to improvements in concrete properties. However, the effects of some types of these materials, such as coal waste and copper slag, have not been investigated seriously. In this study, the effects of several cement-based materials with different pozzolanic reactivity from very active (like silica fume) to approximately inactive (like silica powder) have been studied on the UHPC properties. Since the treatment temperature of 70-100 </span><span class="A6"><span>0</span></span><span>C intensifies the possibility of delayed ettringite formation, thermal curing at 60 </span><span class="A6"><span>0</span></span><span>C and 90 </span><span class="A6"><span>0</span></span><span>C have been selected as the treatment temperatures of low and high risk of delayed ettringite formation, furthermore the results have been compared with the standard thermal curing at 20 </span><span class="A6"><span>0</span></span><span>C. An electrical conductivity method has been used to compare the pozzolanic reaction rate of materials. In this study, compressive strengths, modulus of rupture and rapid chloride migration coefficients have been determined and the investigation of microstructure has been carried out using scanning electron microscopy. The obtained results show that use of heat treatment for the mixtures incorporating materials with low pozzolanic reactivity may reduce the strength and durability of ultra-high performance mixtures. The differences between the results obtained from the thermal curing conditions of 60 </span><span class="A6"><span>0</span></span><span>C and 90 </span><span class="A6"><span>0</span></span><span>C were not significant, however use of thermal curing at 90 </span><span class="A6"><span>0</span></span><span>C requires higher energy demand compared with the thermal curing at 60 </span><span class="A6"><span>0</span></span><span>C, moreover higher risk of delayed ettringite formation is expected.</span>https://ceej.aut.ac.ir/article_2671_c201092c3f5b6c6e90732bbbd65aa6f3.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X50420181023Iran Seismic Design Code Evaluation Through Comparison with NZS 1170.5 and a Critical Look at its Directivity Effects ImplementationIran Seismic Design Code Evaluation Through Comparison with NZS 1170.5 and a Critical Look at its Directivity Effects Implementation725734104610.22060/ceej.2017.11832.5098FAA.NicknamSchool of Civil Engineering, Iran University of Science and Technology, Tehran, IranA.YoussefiSchool of Civil Engineering, Iran University of Science and Technology, Tehran, IranA.MazareiSchool of Civil Engineering, Iran University of Science and Technology, Tehran, IranJournal Article20160824This paper intends to evaluate the existing Iran seismic design code (standard No. 2800) through a comparison process with those of New Zealand seismic code (NZS-1170.5) due to their apparent shape similarity of spectral accelerations being in two parts form. Both standards represent the seismic hazard level of ten percent chance in fifty years. The evaluations made are: the basic design acceleration (A) (in 2800), and the hazard factor (Z) (in NZS), the constant acceleration and constant maximum velocity period ranges of the two spectral shape forms on the four types of site soil conditions, and the approach of implementing the directivity effects by representative parameters, [N(T), in 2800] and [N(D,T), in NZS]. The 2800’s spectral accelerations on the four soil types including the FD-pulses are qualitatively evaluated through hazard-based FD-pulse method. The quantitative results of this study expose that the existing 2800 s’ spectral accelerations need to be increased at relatively small period ranges of 2 s while be decreased at the period ranges longer than 2 s. In brief conclusion, the required design spectral accelerations for buildings which currently are widely constructed in near field sites, are smaller than those of the rationale hazard-based values.This paper intends to evaluate the existing Iran seismic design code (standard No. 2800) through a comparison process with those of New Zealand seismic code (NZS-1170.5) due to their apparent shape similarity of spectral accelerations being in two parts form. Both standards represent the seismic hazard level of ten percent chance in fifty years. The evaluations made are: the basic design acceleration (A) (in 2800), and the hazard factor (Z) (in NZS), the constant acceleration and constant maximum velocity period ranges of the two spectral shape forms on the four types of site soil conditions, and the approach of implementing the directivity effects by representative parameters, [N(T), in 2800] and [N(D,T), in NZS]. The 2800’s spectral accelerations on the four soil types including the FD-pulses are qualitatively evaluated through hazard-based FD-pulse method. The quantitative results of this study expose that the existing 2800 s’ spectral accelerations need to be increased at relatively small period ranges of 2 s while be decreased at the period ranges longer than 2 s. In brief conclusion, the required design spectral accelerations for buildings which currently are widely constructed in near field sites, are smaller than those of the rationale hazard-based values.https://ceej.aut.ac.ir/article_1046_8eb6f173a2898072e57ac6ca5fdc1ce4.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X50420181023Bio-stabilization of Sand by Surface PercolationBio-stabilization of Sand by Surface Percolation735746271110.22060/ceej.2017.13078.5324FAA.KarimianDepartment of Civil Engineering, Imam Khomeini International University, Qazvin, Iran0000-0002-9801-9062M.HassanlouradDepartment of Civil Engineering, Imam Khomeini International University, Qazvin, IranGh.KarimiDepartment of Civil Engineering, Imam Khomeini International University, Qazvin, IranJournal Article20170701Most traditional soil improvement methods are time consuming, expensive, require heavy machinery and are environmentally detrimental. As a more environmentally favorable ground improvement method, the bio-cementation of soil offers an alternative to traditional soil improvement techniques. This method is based on microbial precipitation of calcium carbonate. The role of bacteria is producing urease enzyme to catalyzing the hydrolysis of urea. In the presence of calcium ions, the produced carbonate ions in hydrolysis of urea react with the calcium ions and calcium carbonate sediment is formed. This paper investigates the applicability of the bio-remediation of dry loose sand by surface percolation. To evaluate the success of treatment, a series of laboratory experiments was conducted, including, shear wave velocity, unconfined compressive strength, Brazilian tensile strength, calcium carbonate content and etc. The study revealed that the bio-remediation technique causes the improvement of soil strength as a result of the cementation of sand particles. Furthermore, the surface percolation method has the potential of cementation and stabilization of loose sand with desirable depth. Increase in soil strength and calcium carbonate content decreases with increase of depth. Results also showed that increase of strength due to bio-improvement depends to calcium carbonate content, its spatial distribution in pores and particle-to-particle binding numbers.Most traditional soil improvement methods are time consuming, expensive, require heavy machinery and are environmentally detrimental. As a more environmentally favorable ground improvement method, the bio-cementation of soil offers an alternative to traditional soil improvement techniques. This method is based on microbial precipitation of calcium carbonate. The role of bacteria is producing urease enzyme to catalyzing the hydrolysis of urea. In the presence of calcium ions, the produced carbonate ions in hydrolysis of urea react with the calcium ions and calcium carbonate sediment is formed. This paper investigates the applicability of the bio-remediation of dry loose sand by surface percolation. To evaluate the success of treatment, a series of laboratory experiments was conducted, including, shear wave velocity, unconfined compressive strength, Brazilian tensile strength, calcium carbonate content and etc. The study revealed that the bio-remediation technique causes the improvement of soil strength as a result of the cementation of sand particles. Furthermore, the surface percolation method has the potential of cementation and stabilization of loose sand with desirable depth. Increase in soil strength and calcium carbonate content decreases with increase of depth. Results also showed that increase of strength due to bio-improvement depends to calcium carbonate content, its spatial distribution in pores and particle-to-particle binding numbers.https://ceej.aut.ac.ir/article_2711_618e54f626f991b4193a34bfc878eb08.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X50420181023Determining Impending Slip of Slop and Optimized Embankment Operation Volume of Earth Dams Using a Combination of Neural Networks and Genetic Algorithms (GA)Determining Impending Slip of Slop and Optimized Embankment Operation Volume of Earth Dams Using a Combination of Neural Networks and Genetic Algorithms (GA)747754195510.22060/ceej.2017.11051.4965FAH.R.SabaTafresh University, Tafresh, Iran0000-0001-9331-185XM.KamalianGeotechnical Engineering Research Center, International Institute of Earthquake Engineering and SeismologyI.RaeisizadehAfarinesh institution of higher education, Borujerd, IranJournal Article20151021In this study, impending slip of slope and optimized embankment operation volume of earth dams have been determined using optimization benefiting from a combination of neural networks and genetic algorithms (GA). Further, coefficient of slope stability of earth dam have been determined using neural network and has been compared with outputs of finite element software PLAXIS. In order to training the neural network from derivative data, 150 models of earth dams have been used in finite element software PLAXIS. <br />Slope stability analysis has been done in order to determining the safety factor at desired sliding surface and the most probable fracture process and the least related safety factor. The determination of the most probable fracture process at the impending slip (determining the least safety factor) is the genetic algorithm application. Moreover, another application of genetic algorithm in this research is optimizing the embankment operation volume of earth dam in the manner that minimum of safety factor derived. In this research analysis has been done in order to simpler use of proposed dimensions for engineers using various properties of soil in embankment of earth dam for different heights. Results have been shown as figures and tables which optimal dimensions and volume of the dam without using the software can be derived from them.In this study, impending slip of slope and optimized embankment operation volume of earth dams have been determined using optimization benefiting from a combination of neural networks and genetic algorithms (GA). Further, coefficient of slope stability of earth dam have been determined using neural network and has been compared with outputs of finite element software PLAXIS. In order to training the neural network from derivative data, 150 models of earth dams have been used in finite element software PLAXIS. <br />Slope stability analysis has been done in order to determining the safety factor at desired sliding surface and the most probable fracture process and the least related safety factor. The determination of the most probable fracture process at the impending slip (determining the least safety factor) is the genetic algorithm application. Moreover, another application of genetic algorithm in this research is optimizing the embankment operation volume of earth dam in the manner that minimum of safety factor derived. In this research analysis has been done in order to simpler use of proposed dimensions for engineers using various properties of soil in embankment of earth dam for different heights. Results have been shown as figures and tables which optimal dimensions and volume of the dam without using the software can be derived from them.https://ceej.aut.ac.ir/article_1955_20764bc9370e7ef1bd45f8c97948aab8.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X50420181023Granular Soil Bearing Capacity Improvement Using Waste Plastic MaterialsGranular Soil Bearing Capacity Improvement Using Waste Plastic Materials755764266410.22060/ceej.2017.11924.5100FAA.HooshyarCivil Engineering Department, Islamic Azad University, Hamedan Branch, Hamedan, IranV.RostamiCivil Engineering Department, Islamic Azad University, Hamedan Branch, Hamedan, IranJournal Article20160827<span>Reinforcement is the improvement of total resistance with reinforcing materials (with suitable performance in tension) in soil (with fairly compressive strength and weakness in tension). In the recent years, there have been numerous studies on the application of reinforced soil and bearing capacity of granular soils. Generally, it has been seen that studies are limited to reinforced embankment by geosynthetics and metal stripes and pulleys or even plastic parts and wastes so using plastic waste in embankment has not been considered. Therefore, in this research the effect of using plastic wastes to improve bearing capacity of granular soils has been investigated. The variables are using one type of disposal plastic wastes in different weight percentages in irregular (random) reinforcement and regular reinforcement (with specified layers) in granular embankment. The research was carried out in small laboratory scale using CBR. According to results, placing plastic waste parts in sandy soil increases the bearing capacity remarkably. The optimum values were obtained at 2-2.5 weight percent of plastic parts to sand and also the required energy conditions to attain optimum percentage were examined. In this regard, the strain-stress behavior of soil was studied. The results showed that increasing weight percentage of plastic parts to 2-2.5 in the condition of irregular and regular distribution, respectively, raises the soil elasticity coefficient to 234 and 152%.</span><span>Reinforcement is the improvement of total resistance with reinforcing materials (with suitable performance in tension) in soil (with fairly compressive strength and weakness in tension). In the recent years, there have been numerous studies on the application of reinforced soil and bearing capacity of granular soils. Generally, it has been seen that studies are limited to reinforced embankment by geosynthetics and metal stripes and pulleys or even plastic parts and wastes so using plastic waste in embankment has not been considered. Therefore, in this research the effect of using plastic wastes to improve bearing capacity of granular soils has been investigated. The variables are using one type of disposal plastic wastes in different weight percentages in irregular (random) reinforcement and regular reinforcement (with specified layers) in granular embankment. The research was carried out in small laboratory scale using CBR. According to results, placing plastic waste parts in sandy soil increases the bearing capacity remarkably. The optimum values were obtained at 2-2.5 weight percent of plastic parts to sand and also the required energy conditions to attain optimum percentage were examined. In this regard, the strain-stress behavior of soil was studied. The results showed that increasing weight percentage of plastic parts to 2-2.5 in the condition of irregular and regular distribution, respectively, raises the soil elasticity coefficient to 234 and 152%.</span>https://ceej.aut.ac.ir/article_2664_e2798683e879a9117d1f77156450b286.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X50420181023Performance Evaluation of Anchored Diaphragm Walls under Service LoadsPerformance Evaluation of Anchored Diaphragm Walls under Service Loads765780101110.22060/ceej.2017.12799.5271FAM.Minaei JavidDepartment of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, IranA. R.RahaiDepartment of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, IranA.EslamiDepartment of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, IranJournal Article20170422<span>Nowadays, RC or combined diaphragm walls are vastly used for deep excavation. This type of retaining structures consists of some piles, which are tied-back using the anchors and anchored from their toe to the ground. Concrete or wood plates were used between them. In order to evaluate the effects of some parameters on wall deflection and its internal forces, several models of combined diaphragm walls were selected and analyzed using FLAC software. Before developing the models, Lim and Braiud (1999) case study was modeled with FLAC2D and results were compared with the experimental results indicating acceptable accuracy of the modeling. The numerical model simulated the soldier piles with beam elements and the anchors with cable elements. The soil model used is a modified hyperbolic model with unloading hysteresis. The complete sequence of construction was simulated including the excavation and the placement and stressing of the anchors. The numerical model was calibrated against an instrumented case history. Then a parametric study was conducted. The parameters which was evaluated were: distance and stiffness variation, the bonded and un-bonded length of the anchors, the angle of the anchors and the first raw anchor location. By comparing the different parameters it was observed that the variation of the flexural stiffness of the soldier piles and variation of the bond length of the anchors contained the highest and lowest effect on the maximum horizontal displacement of the wall, respectively. Other analytical results consisting wall deflection vs. geometric characters of the wall were presented and discussed.</span><span>Nowadays, RC or combined diaphragm walls are vastly used for deep excavation. This type of retaining structures consists of some piles, which are tied-back using the anchors and anchored from their toe to the ground. Concrete or wood plates were used between them. In order to evaluate the effects of some parameters on wall deflection and its internal forces, several models of combined diaphragm walls were selected and analyzed using FLAC software. Before developing the models, Lim and Braiud (1999) case study was modeled with FLAC2D and results were compared with the experimental results indicating acceptable accuracy of the modeling. The numerical model simulated the soldier piles with beam elements and the anchors with cable elements. The soil model used is a modified hyperbolic model with unloading hysteresis. The complete sequence of construction was simulated including the excavation and the placement and stressing of the anchors. The numerical model was calibrated against an instrumented case history. Then a parametric study was conducted. The parameters which was evaluated were: distance and stiffness variation, the bonded and un-bonded length of the anchors, the angle of the anchors and the first raw anchor location. By comparing the different parameters it was observed that the variation of the flexural stiffness of the soldier piles and variation of the bond length of the anchors contained the highest and lowest effect on the maximum horizontal displacement of the wall, respectively. Other analytical results consisting wall deflection vs. geometric characters of the wall were presented and discussed.</span>https://ceej.aut.ac.ir/article_1011_e8faaa2a534b76ae40ae5db5f35daf92.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X50420181023Ultimate Bearing Capacity of Composite Shell Annular Foundations in Cohesionless SoilUltimate Bearing Capacity of Composite Shell Annular Foundations in Cohesionless Soil781792103910.22060/ceej.2017.12628.5235FAM.KAZEMICivil Engineering Department, Ferdowsi University of Mashhad, Mashhad, IranJ.Bolouri BazazCivil Engineering Department, Ferdowsi University of Mashhad, Mashhad, IranJournal Article20170307The foundation shape effects on the stress distribution induced in the soil. Moreover, it has influence on the failure mechanism of the soil. For these reasons, it plays an important role in the ultimate bearing capacity of the foundation. Due to lack of materials, the new design methods attempt to utilize the least amount of material and achieve the maximum efficiency. If shell elements are employed in composite foundations, and the interaction effects are considered, the cost can be reduced. This paper aims to compare the geotechnical performance of the composite annular shell foundation with that of the annular one. For this purpose, the ultimate bearing capacity and the settlement of these foundations are experimentally modeled for various shell angles. The findings prove that the ultimate bearing capacity of the composite foundations is more than that of the annular one. Furthermore, it is observed that increasing the shell angle reduces the ultimate bearing capacity. Moreover, the shell efficiency factor is decreased by increasing the soil relative density. This phenomenon shows that the shells perform more appropriately in low-density soils. Additionally, a novel relation is proposed for predicting the ultimate bearing capacity of the composite shell. It is worth emphasizing that adding the edge beam to composite foundations improves its performance in settlements during failure. Moreover, the efficiency of foundations with edge beams is more than the ones without beam in soils with any density. Hence, using of shells in annular foundation enhances its ultimate bearing capacity.The foundation shape effects on the stress distribution induced in the soil. Moreover, it has influence on the failure mechanism of the soil. For these reasons, it plays an important role in the ultimate bearing capacity of the foundation. Due to lack of materials, the new design methods attempt to utilize the least amount of material and achieve the maximum efficiency. If shell elements are employed in composite foundations, and the interaction effects are considered, the cost can be reduced. This paper aims to compare the geotechnical performance of the composite annular shell foundation with that of the annular one. For this purpose, the ultimate bearing capacity and the settlement of these foundations are experimentally modeled for various shell angles. The findings prove that the ultimate bearing capacity of the composite foundations is more than that of the annular one. Furthermore, it is observed that increasing the shell angle reduces the ultimate bearing capacity. Moreover, the shell efficiency factor is decreased by increasing the soil relative density. This phenomenon shows that the shells perform more appropriately in low-density soils. Additionally, a novel relation is proposed for predicting the ultimate bearing capacity of the composite shell. It is worth emphasizing that adding the edge beam to composite foundations improves its performance in settlements during failure. Moreover, the efficiency of foundations with edge beams is more than the ones without beam in soils with any density. Hence, using of shells in annular foundation enhances its ultimate bearing capacity.https://ceej.aut.ac.ir/article_1039_a30b4df09addc96b1b5fd5e8c6e94323.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X50420181023The Experimental Investigation of the Effect of Heating-Cooling Cycle Number of Rock on Mode I Fracture ToughnessThe Experimental Investigation of the Effect of Heating-Cooling Cycle Number of Rock on Mode I Fracture Toughness793800196510.22060/ceej.2017.12659.5245FAA.JabbariDepartment of Mining Engineering, Imam Khomeini International University, Qazvin, IranM.HosseiniDepartment of Mining Engineering, Imam Khomeini International University, Qazvin, IranJournal Article20170313There are small cracks in rocks; therefore, when rocks undergo loading, stresses are concentrated at the tip of cracks causing rock fracture before reaching its ultimate strength. The critical value of the stress intensity factor at the crack tip is called fracture toughness. The tensile strength of rocks is weak; therefore, Mode I (tensile mode) is the most critical loading mode. In some cases, rocks continuously experience heating-cooling. Therefore, it is necessary to determine the effect of heating-cooling cycle number on mode I fracture toughness, which is the objective of this research. To achieve this objective, we conducted three-point bending test on semi-circular specimens of three types of natural rock including sandstone, limestone and andesite to determine the mode I fracture toughness. A series of concrete specimen was also tested for further investigation. Petrography and X-ray diffraction analysis (XRD) were conducted to understand the rock composition. The specimens were heated up to 700° C in 1, 5 and 10 cycles and then cooled. A series of experiments were also conducted on the specimens at room temperature (25°C). According to the rising of temperature in firing process, the rate of temperature rise for specimens in the electric furnace is determined to be 15 ° C per minute. Fracture toughness of andesite rock, sandstone and limestone specimens decreases under cyclic conditions. Results indicate the generation and expansion of micro fractures in some rocks after undergoing cycles of heating-cooling, which causing an increase in the effective porosity and decrease in the P-wave velocity in rocks.There are small cracks in rocks; therefore, when rocks undergo loading, stresses are concentrated at the tip of cracks causing rock fracture before reaching its ultimate strength. The critical value of the stress intensity factor at the crack tip is called fracture toughness. The tensile strength of rocks is weak; therefore, Mode I (tensile mode) is the most critical loading mode. In some cases, rocks continuously experience heating-cooling. Therefore, it is necessary to determine the effect of heating-cooling cycle number on mode I fracture toughness, which is the objective of this research. To achieve this objective, we conducted three-point bending test on semi-circular specimens of three types of natural rock including sandstone, limestone and andesite to determine the mode I fracture toughness. A series of concrete specimen was also tested for further investigation. Petrography and X-ray diffraction analysis (XRD) were conducted to understand the rock composition. The specimens were heated up to 700° C in 1, 5 and 10 cycles and then cooled. A series of experiments were also conducted on the specimens at room temperature (25°C). According to the rising of temperature in firing process, the rate of temperature rise for specimens in the electric furnace is determined to be 15 ° C per minute. Fracture toughness of andesite rock, sandstone and limestone specimens decreases under cyclic conditions. Results indicate the generation and expansion of micro fractures in some rocks after undergoing cycles of heating-cooling, which causing an increase in the effective porosity and decrease in the P-wave velocity in rocks.https://ceej.aut.ac.ir/article_1965_fb0ba26b961c295db998ff3bb7defe5e.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X50420181023Prioritizing Risks and Proposing a Risk Management Model in Wind Farms Developments According to Project Management StandardPrioritizing Risks and Proposing a Risk Management Model in Wind Farms Developments According to Project Management Standard801812265710.22060/ceej.2017.12206.5147FAM.SaybaniAmirkabir University of Technology, Tehran, IranF.HATAMIAmirkabir University of Technology, Tehran, IranH.HeraviAmirkabir University of Technology, Tehran, IranJournal Article20161203This article proposed project risk management model based on different project phases with emphasis on construction and installation phases and considering risk management in powerhouse projects. Accordingly, a case study on Manjil Wind Farm was conducted to firstly detect the most important risks of construction and installation phases in this project, considering different potential risks that identified and then, to propose the risk management model to evaluate the effect size, the possibility of diagnosis and risk incidence, and their impact on the main objectives of this project which are time, quality, expenses and security. Moreover, a model was proposed to prioritize the detected risks in this project based on group opinions and Analytic Hierarchy Process (AHP) method, and the following results were gathered. After determining the detected risks priorities, react or response programs to critical and important risks were provided and the consequence of react or revision actions in risk management program were recorded with offering some comments.This article proposed project risk management model based on different project phases with emphasis on construction and installation phases and considering risk management in powerhouse projects. Accordingly, a case study on Manjil Wind Farm was conducted to firstly detect the most important risks of construction and installation phases in this project, considering different potential risks that identified and then, to propose the risk management model to evaluate the effect size, the possibility of diagnosis and risk incidence, and their impact on the main objectives of this project which are time, quality, expenses and security. Moreover, a model was proposed to prioritize the detected risks in this project based on group opinions and Analytic Hierarchy Process (AHP) method, and the following results were gathered. After determining the detected risks priorities, react or response programs to critical and important risks were provided and the consequence of react or revision actions in risk management program were recorded with offering some comments.https://ceej.aut.ac.ir/article_2657_e9fc45607e59691a9d1fc5ab7ed53e67.pdf