Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 56 7 2024 09 22 Experimental investigation and numerical analysis of the effect of zinc oxide nanoparticles on the permeability of concrete in hydraulic channels Experimental investigation and numerical analysis of the effect of zinc oxide nanoparticles on the permeability of concrete in hydraulic channels 803 826 5459 10.22060/ceej.2024.23012.8090 FA Kamran Rahmati Shadabad Faculty of Civil Engineering, University of Tabriz, Tabriz, Iran. Ali Foroughi-Asl Faculty of Civil Engineering, University of Tabriz, Tabriz, Iran. Journal Article 2024 02 23 Concrete is a fundamental building material widely employed in various construction projects, particularly in ensuring the structural integrity of hydraulic channels against water and chemical infiltration. In this study, we investigate, for the first time, the impact of zinc oxide nanoparticles on the permeability and mechanical properties of concrete through experimental and laboratory analyses. Uniaxial compressive tests were conducted to determine the compressive and tensile strength of concrete specimens containing zinc oxide nanoparticles at concentrations of 0%, 0.1%, 0.5%, 1.0%, and 1.5% at 7 and 28 days of age. Additionally, permeability and water absorption rates were assessed. The findings reveal that the mechanical strength of concrete increases with the addition of nanoparticles up to a certain threshold. Remarkably, at a nanoparticle concentration of 0.1%, the permeability of concrete decreased by 97% compared to the control sample. This enhancement can be attributed to the ability of nanomaterials to enhance mechanical strength by fostering a denser and less porous microstructure in the mortar-concrete matrix. Furthermore, behavioural models were developed utilizing genetic algorithm programming to depict the time-dependent properties of concrete specimens incorporating nanoparticles under various compressive and tensile conditions at different ages. Consequently, this study endeavours to predict the concrete mix design incorporating nanoparticles using neural networks in conjunction with the genetic algorithm approach. The aim of this modelling is to demonstrate the accuracy of neural networks in forecasting the compressive, tensile, and permeability properties of concrete with varying proportions of zinc oxide nanoparticles. Concrete is a fundamental building material widely employed in various construction projects, particularly in ensuring the structural integrity of hydraulic channels against water and chemical infiltration. In this study, we investigate, for the first time, the impact of zinc oxide nanoparticles on the permeability and mechanical properties of concrete through experimental and laboratory analyses. Uniaxial compressive tests were conducted to determine the compressive and tensile strength of concrete specimens containing zinc oxide nanoparticles at concentrations of 0%, 0.1%, 0.5%, 1.0%, and 1.5% at 7 and 28 days of age. Additionally, permeability and water absorption rates were assessed. The findings reveal that the mechanical strength of concrete increases with the addition of nanoparticles up to a certain threshold. Remarkably, at a nanoparticle concentration of 0.1%, the permeability of concrete decreased by 97% compared to the control sample. This enhancement can be attributed to the ability of nanomaterials to enhance mechanical strength by fostering a denser and less porous microstructure in the mortar-concrete matrix. Furthermore, behavioural models were developed utilizing genetic algorithm programming to depict the time-dependent properties of concrete specimens incorporating nanoparticles under various compressive and tensile conditions at different ages. Consequently, this study endeavours to predict the concrete mix design incorporating nanoparticles using neural networks in conjunction with the genetic algorithm approach. The aim of this modelling is to demonstrate the accuracy of neural networks in forecasting the compressive, tensile, and permeability properties of concrete with varying proportions of zinc oxide nanoparticles. https://ceej.aut.ac.ir/article_5459_9d05c2d955b24bd5d20b1638156ea0ef.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 56 7 2024 09 22 Remediation of diesel contaminated soil using chemical and biological surfactants Remediation of diesel contaminated soil using chemical and biological surfactants 827 844 5463 10.22060/ceej.2024.21362.7697 FA Sahar Mansoury Civil And Environmental Engineering Faculty; Tarbiat Modares University Nader Mokhtarani Civil and Environmental Engineering Faculty, Tarbiat Modares University Journal Article 2022 05 02 Today, soil pollution by crude oil and its derivatives is of great importance, and it has become one of the serious environmental challenges in the world. This study aimed to remediate diesel-contaminated soil by enhancing the soil-washing process using chemical and biological surfactants on a laboratory scale. For this purpose, the chemical surfactants of Triton X 100, SDS, and the synthesized natural surfactant of rhamnolipid were used. During this process, carried out in a Plexiglas column with an approximate volume of 400 ml, the effect of parameters such as surfactant concentration, solution pH, soil texture, flow direction, and pollutant concentration as independent variables on soil treatment was investigated. In this study, the maximum total petroleum hydrocarbonsremoval efficiency of 78% from contaminated soil (containing 10% clay and contaminated with 10,000diesel) was achieved after 12 hours of soil washing using a combined surfactant of TX100-SDS (mixing ratio of 80:20 and a concentration of 5) with a flow rate of 1.5at a pH of 7.8. Although in this research, rhamnolipid had a lower removal efficiency than other surfactants, due to its biodegradability and lower toxicity compared to other chemical surfactants used, as a potentially sustainable option to achieve efficient application and better effectiveness; it requires more investigation and research. Today, soil pollution by crude oil and its derivatives is of great importance, and it has become one of the serious environmental challenges in the world. This study aimed to remediate diesel-contaminated soil by enhancing the soil-washing process using chemical and biological surfactants on a laboratory scale. For this purpose, the chemical surfactants of Triton X 100, SDS, and the synthesized natural surfactant of rhamnolipid were used. During this process, carried out in a Plexiglas column with an approximate volume of 400 ml, the effect of parameters such as surfactant concentration, solution pH, soil texture, flow direction, and pollutant concentration as independent variables on soil treatment was investigated. In this study, the maximum total petroleum hydrocarbonsremoval efficiency of 78% from contaminated soil (containing 10% clay and contaminated with 10,000diesel) was achieved after 12 hours of soil washing using a combined surfactant of TX100-SDS (mixing ratio of 80:20 and a concentration of 5) with a flow rate of 1.5at a pH of 7.8. Although in this research, rhamnolipid had a lower removal efficiency than other surfactants, due to its biodegradability and lower toxicity compared to other chemical surfactants used, as a potentially sustainable option to achieve efficient application and better effectiveness; it requires more investigation and research. https://ceej.aut.ac.ir/article_5463_2d1ef8f39d2c1590daf9a3737c8a931d.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 56 7 2024 09 22 The Necessity of Modeling the Column Beam Joint Panel Zone in Reinforced Concrete Structures with Behavioral Degradation The Necessity of Modeling the Column Beam Joint Panel Zone in Reinforced Concrete Structures with Behavioral Degradation 845 864 5464 10.22060/ceej.2024.22089.7900 FA Ahmadreza Fakhriyat Department of Civil Engineering, Faculty of Engineering, Behbahan Khatam Alanbia University of Technology, Sasan Motaghed Mohammad Sadegh Shahidzadeh Engineering Department, Faculty of Civil Engineering, Behbahan Khatam Alanbia University of Technology, Behbahan, Iran 0000-0001-5910-7724 Journal Article 2023 01 10 <span style="letter-spacing: .05pt;">This study investigates the impact of incorporating panel zones into the numerical modelling of reinforced concrete moment-resisting frames (RC MRFs). Eight- and twelve-story RC MRF models were created using OpenSees software. The effects of panel zone inclusion were analyzed by comparing the results of nonlinear static (cyclic), dynamic, and incremental dynamic analyses. All models employed the Ibarra-Medina-Krawinkler (IMK) degradation model to account for material behaviour. The static analyses revealed minimal differences between models with and without panel zones. However, the influence of panel zones became significant in the dynamic analyses. Fragility curves demonstrated that models incorporating panel zones reached the collapse limit state at lower earthquake intensity levels. Additionally, the nonlinear time-history analysis showed that while panel zone effects were negligible in the linear response range, structures with modelled panel zones exhibited larger displacements upon entering the nonlinear region. These findings highlight the importance of considering panel zones in numerical models, particularly when evaluating the seismic performance of RC MRFs. Panel zones play a crucial role in capturing the inelastic response and collapse behaviour of structures under earthquake loading.</span> <span style="letter-spacing: .05pt;">This study investigates the impact of incorporating panel zones into the numerical modelling of reinforced concrete moment-resisting frames (RC MRFs). Eight- and twelve-story RC MRF models were created using OpenSees software. The effects of panel zone inclusion were analyzed by comparing the results of nonlinear static (cyclic), dynamic, and incremental dynamic analyses. All models employed the Ibarra-Medina-Krawinkler (IMK) degradation model to account for material behaviour. The static analyses revealed minimal differences between models with and without panel zones. However, the influence of panel zones became significant in the dynamic analyses. Fragility curves demonstrated that models incorporating panel zones reached the collapse limit state at lower earthquake intensity levels. Additionally, the nonlinear time-history analysis showed that while panel zone effects were negligible in the linear response range, structures with modelled panel zones exhibited larger displacements upon entering the nonlinear region. These findings highlight the importance of considering panel zones in numerical models, particularly when evaluating the seismic performance of RC MRFs. Panel zones play a crucial role in capturing the inelastic response and collapse behaviour of structures under earthquake loading.</span> https://ceej.aut.ac.ir/article_5464_b426b30042abbc15e363cb679bbc937d.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 56 7 2024 09 22 Seismic Evaluation of eccentrically braced frames without diagonal members Seismic Evaluation of eccentrically braced frames without diagonal members 865 884 5465 10.22060/ceej.2024.22548.7992 FA Farid Mahmoudi Amirkabir university of technology Alireza Rahai 0000-0002-9101-0794 Hatami Farzad 0000-0002-4860-4298 Journal Article 2023 07 11 Eccentrically braced frames are one type of lateral load-bearing system due to their acceptable ductility and proportional stiffness. However, they have some limitations that need improvement. One limitation is insufficient architectural space creation, especially for short spans which leads to using link beams with intermediate and long lengths that have weaker energy absorption compared to links with short lengths. Another limitation is their costly and time-consuming replacement. To address these limitations, this research proposes removing diagonal elements from eccentrically braced frames and increasing beam depth outside links which provides more proportional stiffness and improved architectural space for designers. Additionally, using replaceable connections between links and main beams reduces repair costs after earthquakes. Numerical modeling was used to investigate this idea along with laboratory studies. Finally, the ratio between increased beam depth outside links and frame stiffness was found through numerical modelling samples with gradual increases in beam depth without braces. Eccentrically braced frames are one type of lateral load-bearing system due to their acceptable ductility and proportional stiffness. However, they have some limitations that need improvement. One limitation is insufficient architectural space creation, especially for short spans which leads to using link beams with intermediate and long lengths that have weaker energy absorption compared to links with short lengths. Another limitation is their costly and time-consuming replacement. To address these limitations, this research proposes removing diagonal elements from eccentrically braced frames and increasing beam depth outside links which provides more proportional stiffness and improved architectural space for designers. Additionally, using replaceable connections between links and main beams reduces repair costs after earthquakes. Numerical modeling was used to investigate this idea along with laboratory studies. Finally, the ratio between increased beam depth outside links and frame stiffness was found through numerical modelling samples with gradual increases in beam depth without braces. https://ceej.aut.ac.ir/article_5465_4275f89744278864da88c2fda68ec4e9.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 56 7 2024 09 22 Numerical investigation of swelling soil behavior and its effect on gas well casing internal forces based on unsaturated soil mechanics, case study: Khangiran, Sarakhs Numerical investigation of swelling soil behavior and its effect on gas well casing internal forces based on unsaturated soil mechanics, case study: Khangiran, Sarakhs 885 908 5466 10.22060/ceej.2024.22616.8006 FA Mehrab Balighi Civil engineering faculty, Department of engineering, Ferdowsi University of Mashhad, Iran Mohammad Saleh Baradaran Department of Civil Engineering, Ferdowsi university of Mashhad, Iran 0000-0002-8523-1283 Ali Akhtarpour Civil Engineering Department, Engineering Faculty, ferodwsi University of Mashhad,Mashhad, Iran 0000-0003-1654-0194 Journal Article 2023 08 17 The majority of building and infrastructure projects are typically situated on soils that have a greater elevation than the underlying water table. As a consequence, these soils exist in an unsaturated state, resulting in the development of matric suction inside them. The manipulation of soil saturation levels significantly influences its mechanical and hydraulic characteristics. Swelling soils refer to a type of soil that undergoes volumetric expansion as a result of moisture absorption and a subsequent decrease in matric suction. Hence, this matter gives rise to irreversible harm in the realm of infrastructure, transportation networks, and facilities such as oil and gas. This study focuses on the numerical analysis and discussion of the swelling soil surrounding a gas well located within the Khangiran gas refinery. The findings from the numerical simulation demonstrated that, at the critical juncture of the steel pipe within the well structure, the tensile force induced by soil expansion infiltrates the surrounding area. To withstand this force, the design and permissible thickness of the well pipe can be evaluated using two approaches: load coefficients-resistance and allowable resistance. The action is permissible. The findings indicate that the thicknesses obtained are relatively small, thereby suggesting that there is no significant risk associated with soil swelling and the resultant tensile force exerted on the well casing. However, it is important to note that the durability of the well body's steel material over time is crucial in preventing breakage due to soil swelling-induced tension. The majority of building and infrastructure projects are typically situated on soils that have a greater elevation than the underlying water table. As a consequence, these soils exist in an unsaturated state, resulting in the development of matric suction inside them. The manipulation of soil saturation levels significantly influences its mechanical and hydraulic characteristics. Swelling soils refer to a type of soil that undergoes volumetric expansion as a result of moisture absorption and a subsequent decrease in matric suction. Hence, this matter gives rise to irreversible harm in the realm of infrastructure, transportation networks, and facilities such as oil and gas. This study focuses on the numerical analysis and discussion of the swelling soil surrounding a gas well located within the Khangiran gas refinery. The findings from the numerical simulation demonstrated that, at the critical juncture of the steel pipe within the well structure, the tensile force induced by soil expansion infiltrates the surrounding area. To withstand this force, the design and permissible thickness of the well pipe can be evaluated using two approaches: load coefficients-resistance and allowable resistance. The action is permissible. The findings indicate that the thicknesses obtained are relatively small, thereby suggesting that there is no significant risk associated with soil swelling and the resultant tensile force exerted on the well casing. However, it is important to note that the durability of the well body's steel material over time is crucial in preventing breakage due to soil swelling-induced tension. https://ceej.aut.ac.ir/article_5466_3b5e2c9be5002e87e0477099db5ff21b.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 56 7 2024 09 22 Evaluation of adaptation solutions to climate change and ocean pattern (Study area: Gavkhoni watershed) Evaluation of adaptation solutions to climate change and ocean pattern (Study area: Gavkhoni watershed) 909 930 5467 10.22060/ceej.2024.22691.8028 FA Maziar Masoudian Department of Environmental Engineering. Science and Research Branch, Islamic Azad University, Tehran, Iran Hamid Kardan Moghadam Water Research Institute, Ministry of Energy Water Research Institute, Tehran, Iran. Seyedeh Hoda Rahmati Department of Environmental Engineering. Science and Research Branch, Islamic Azad University, Tehran, Iran Journal Article 2023 09 19 This study analyzed the effect of climate change and the Anso phenomenon on the water resources of the Gavakhuni catchment area. CESM2 and IPSL-CM6A-LR climate simulation models were used to simulate climate change and El Nino and La Nino phenomena as two oceanic phenomena. The results of the climate simulation for the period 2020 to 2040 showed that the average precipitation in the whole area has decreased by 14 mm and the average temperature has increased by 0.94. Examining the future conditions of the basin in terms of development indicates a deficit of 411 MCM of underground water resources, which will increase to 431 MCM in the conditions of climate change. The simulation results in the Enso phenomenon also showed that the situation of water resources improved in the El Nino event and the deficit reached 311 MCM and in the La Niño event it reached 481 MCM. The impact of El Niño as an oceanic phenomenon was evaluated positively and La Niño and climate change scenarios were evaluated negatively. The uncertainty of the deficit of underground water resources was simulated in two ocean phenomena with a volume of 163 million cubic meters per year and 14 MCM in three climate change scenarios. 4 solutions of water transfer (S1), reduction of exploitation of underground water resources (S2), increase of water productivity in the agricultural sector (S3) and increase of agricultural efficiency (S4) were evaluated in these conditions. The results showed that although the transfer of water and reduction of exploitation can have a great impact on the balance of underground water resources, according to the environmental, economic and social considerations, it is possible to obtain good results from the solutions to increase productivity and efficiency. This study analyzed the effect of climate change and the Anso phenomenon on the water resources of the Gavakhuni catchment area. CESM2 and IPSL-CM6A-LR climate simulation models were used to simulate climate change and El Nino and La Nino phenomena as two oceanic phenomena. The results of the climate simulation for the period 2020 to 2040 showed that the average precipitation in the whole area has decreased by 14 mm and the average temperature has increased by 0.94. Examining the future conditions of the basin in terms of development indicates a deficit of 411 MCM of underground water resources, which will increase to 431 MCM in the conditions of climate change. The simulation results in the Enso phenomenon also showed that the situation of water resources improved in the El Nino event and the deficit reached 311 MCM and in the La Niño event it reached 481 MCM. The impact of El Niño as an oceanic phenomenon was evaluated positively and La Niño and climate change scenarios were evaluated negatively. The uncertainty of the deficit of underground water resources was simulated in two ocean phenomena with a volume of 163 million cubic meters per year and 14 MCM in three climate change scenarios. 4 solutions of water transfer (S1), reduction of exploitation of underground water resources (S2), increase of water productivity in the agricultural sector (S3) and increase of agricultural efficiency (S4) were evaluated in these conditions. The results showed that although the transfer of water and reduction of exploitation can have a great impact on the balance of underground water resources, according to the environmental, economic and social considerations, it is possible to obtain good results from the solutions to increase productivity and efficiency. https://ceej.aut.ac.ir/article_5467_7c4121d27bf970f00f1dfdcee8f43a5d.pdf