Amirkabir University of TechnologyAUT Journal of Civil Engineering2588-28996420221201A Two-Stage Procedure for Optimum Design of Plate Girders Using a Meta-heuristic Algorithm435446517510.22060/ajce.2023.21782.5811ENSeyed AmirBanimahdDepartment of Civil Engineering, Faculty of Engineering, Ardakan University, Ardakan, Iran0000-0003-3235-4455Mohammad AmirRahemiInternational Institute of Earthquake Engineering and Seismology, Tehran, IranJournal Article20220917The main aim in the design of welded plate girders is to minimize the weight of the beam while satisfying design requirements which turns the design procedure into a nonlinear and complex optimization problem. In this paper, a two-stage optimization procedure is introduced to find the best design of welded plate girders in terms of both safety and economy. The total weight of the girder is considered as the objective function where some predefined constraints are applied using penalty functions to restrict the solution space. In the first stage, the theoretical optimum values of girder dimensions are obtained using the Artificial Bee Colony (ABC)<em> </em>algorithm based on the optimum use of steel material while satisfying restrictions on the flexural and shear strength, permissible deflection, and proportioning limits. Since the plate dimension values obtained by the first stage may not be available in the market, the second stage of optimization is carried out to reach a safe and economical design by considering available plate dimension values. The critical ratio of the designing procedure is obtained equal to one, which is the ideal design. To demonstrate the effectiveness of the proposed method, two examples are considered at the end of this article. The results show that the dimension of the plate girder calculated by the proposed approach is more economical and practical than that obtained by the traditional trial and error techniques.https://ajce.aut.ac.ir/article_5175_ffd2257b586a72d1fa75f4ba2ad914e6.pdfAmirkabir University of TechnologyAUT Journal of Civil Engineering2588-28996420221201Numerical Evaluation of Unreinforced Masonry Brick Walls Retrofitted by Polypropylene Straps Subjected to Lateral Loading447460522310.22060/ajce.2023.21848.5813ENKouroshNasrollahzadehDepartment of Civil Engineering, K. N. Toosi University of Technology, Tehran, IranShahradEbrahimzadehUniversity of Southern Queensland, Centre for Future Materials, Toowoomba, Australia0000-0002-5140-3649Journal Article20221012This study investigated the two half-scale (1:2) unreinforced masonry walls, sharing identical dimensions, geometry, and construction characteristics, which were subjected to simultaneous lateral and vertical constant loading. While the first specimen represented an unreinforced masonry wall, the second specimen underwent a transformative retrofitting process involving the incorporation of vertical, horizontal, and oblique Polypropylene straps. To further optimize the retrofit, the minimum area of the wall was reinforced using shotcrete mortar with weak cement. The retrofitting material was defined by introducing Polypropylene straps and shotcrete mortar into the first model, and a comprehensive evaluation of the reference model was conducted. The pushover analysis, conducted through monotonic loading simulations, effectively replicated the essential behaviors observed in the primary experimental specimens. Remarkably, the experimental results exhibited striking agreement with the numerical outcomes derived from the employment of ABAQUS finite element software. Notably, these results unveiled the efficacy of the retrofitting technique, highlighting a remarkable enhancement in the ultimate lateral displacement by 140% and an impressive 71% increase in loading capacity. Furthermore, the retrofitting process induced a notable shift in the failure mode from diagonal tension and shear cracks to a more desirable flexural rocking mechanism, reinforcing the structural integrity of the masonry walls.https://ajce.aut.ac.ir/article_5223_fc0cc602ce843b5393684a7fc1b566bc.pdfAmirkabir University of TechnologyAUT Journal of Civil Engineering2588-28996420221201Extended power series solution for Perkins-Kern-Nordgren model of hydraulic fracture461468518610.22060/ajce.2023.19737.5814ENAliAsgariDepartment of Civil Engineering, Faculty of Engineering and Technology, University of Mazandaran, Babolsar, Iran0000-0002-2359-8696Journal Article20221111The extended Power Series (XPS) method can be extremely useful for solving nonlinear equations with regular and irregular singular points. The extended power series is considered times a logarithm or times a fractional power of x, etc.). This research shows it is simple to solve approximately the Perkins-Kern-Nordgren (PKN) model of hydraulic fracture. To illustrate the effectiveness and convenience of the XPS method, we consider the two cases of dimensionless PKN equation containing the M-scaling and -scaling. The results compared with available analytical results verified excellent agreements.https://ajce.aut.ac.ir/article_5186_c8d12113e2258af31914e88130b917f6.pdfAmirkabir University of TechnologyAUT Journal of Civil Engineering2588-28996420230826BIM-based resource trade-off in dam project scheduling using Atomic Orbital Search (AOS) algorithm469492522410.22060/ajce.2023.22042.5818ENMiladBaghalzadeh ShishehgarkhanehDepartment of Civil Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran.0000-0002-7737-7661SinaFardmoradiniaDepartment of Civil Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran.0000-0003-3539-7311AframKeivaniDepartment of Civil Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran.MahdiAziziDepartment of Civil Engineering, University of Tabriz, Tabriz,Iran.
Department of Civil Engineering, Near East University, Nicosia, Cyprus.0000-0002-2364-2757Journal Article20221222Dam construction projects are considered complicated, large, and heavy projects throughout the world, requiring a high number of workers, stakeholders, equipment, cost, and time. Hence, their resource management and trade-off are one of the most important tasks for project managers and schedulers. Concerning the Building Information Modeling (BIM) method and metaheuristic algorithm, this study proposes a framework for resource trade-offs in dam construction project scheduling. Atomic Orbital Search (AOS) is employed as a newly developed metaheuristic algorithm based on quantum mechanics principles. First, a 3D model of the dam construction project is modeled using the BIM process and project management software. Regarding the minimization of time, cost, risk, and maximum quality, an optimization problem is formed, and the AOS's capacity to solve this issue is assessed, and its outcomes are compared with different four metaheuristic algorithms. Meanwhile, all optimization processes were carried out. To identify the statistical measures considering a predetermined stopping condition, 30 separate optimization runs are carried out. The outcomes show that the AOS algorithm can deliver competitive and exceptional results when handling trade-offs between various resource alternatives in dam construction. Consequently, project managers can use the AOS optimization algorithm in their large and intricate construction projects in dealing with resource trade-off problems.https://ajce.aut.ac.ir/article_5224_cc384c68ad503482fb24e6d1e3b512ae.pdfAmirkabir University of TechnologyAUT Journal of Civil Engineering2588-28996420221201Competence and affective commitment as mediators of the effect of job characteristics on the performance of Iranian supervising engineers– supervising engineers’ perspective493508523110.22060/ajce.2023.21997.5820ENAliKatebiDepartment of Civil Engineering, Kharazmi University, Tehran, Iran.Zahra AlsadatArdestaniDepartment of Urban Planning and Design, Kharazmi University, Tehran, Iran.AliBordbarDepartment of Civil Engineering, Kharazmi University, Tehran, Iran.Journal Article20230103The job performance of Supervising Engineers has a key role in project monitoring and controlling.<br />The growing complexity and accelerated nature of construction projects, driven by the adoption of new technologies, have amplified the significance of job performance among supervising engineers. Therefore, this study aimed to develop a model based on job characteristics, competence, and affective commitment, to quantitatively investigate the influencing factors on supervising engineers’ performance in building projects. The proposed model was analyzed with the Partial Least-Squares Structural Equation Modeling (PLS-SEM) method. Questionnaires were distributed among civil engineers who are members of the Iran Construction Engineering Organization (IRCEO). The majority of respondents were male and had more than 5 years of work experience. The primary contribution of this study to the existing body of knowledge lies in the comparison of the impact of affective commitment and competence on the performance of supervising engineers. Additionally, this study has identified the moderator variables within this model. While the results indicated that competence had a greater influence on the performance of supervising engineers compared to other factors (β=0.259, p≤0.05), it is noteworthy that the impact of affective commitment (β=0.258, p≤0.01) was nearly equivalent. In addition, the moderating effects of work experience, age, marital status and family support were investigated.https://ajce.aut.ac.ir/article_5231_a24281a03c28fa405eb29b54ebfe5d9b.pdfAmirkabir University of TechnologyAUT Journal of Civil Engineering2588-28996420221201Numerical Investigation on Structural Behaviors of Deficient Steel CHS Long Columns Strengthened Using CFRP509520522110.22060/ajce.2023.22325.5825ENOmidYousefiDepartment of Civil Engineering, Nikshahr Branch, Islamic Azad University, Nikshahr, Iran0000-0002-2430-440XJournal Article20230409<span style="letter-spacing: .05pt;">Structures often suffer damage due to various factors, including accidental loads, corrosion, and reduced strength, necessitating the need for repairs. The use of Carbon Fiber Reinforced Polymer (CFRP) to strengthen steel members has gained considerable attention in recent decades. However, most previous research has focused on studying the behavior of non-deficient steel structures. This study aims to investigate long steel circular columns with primary defects in vertical and horizontal notches, and examine the effects of CFRP retrofitting. A total of fifteen specimens of steel long Circular Hollow Section (CHS) columns, each with the same height but varying damage dimensions, were analyzed using ABAQUS 2016 software under compressive load. The main challenge with long columns is global buckling under compressive loads. To improve the accuracy of the analysis, a combined method was employed to study the post-buckling behavior of the plastic zone. Specifically, the specimens underwent elastic buckling analysis followed by RIKS non-linear analysis considering both general and local imperfections. The results showed that defects in the steel columns reduced the load-bearing capacity by up to 52%. Horizontal defects had a greater impact on reducing the ultimate load compared to vertical damage (up to 13%). Additionally, deficiencies significantly affected the buckling of the defect area, resulting in axial deformation. CFRP retrofitting strengthened the columns, increasing the ultimate load capacity (up to 51%), delaying defect buckling, controlling fractures, and reducing stresses in the damaged zone.</span>https://ajce.aut.ac.ir/article_5221_3ff31b21755de79edf5668a07bd37f81.pdf