Research Article
مهندسی عمران-سازه های هیدرولیکی
roozbeh aghamajidi; amir kamanbedast
Abstract
In this study, the effect of change of flow discharge on the scouring around the piers of the fifth bridge of Dezful was investigated using the Hsec-RAS numerical model. For this purpose, a hydraulic model was created from the range of the river in which the bridge is located in the software by using ...
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In this study, the effect of change of flow discharge on the scouring around the piers of the fifth bridge of Dezful was investigated using the Hsec-RAS numerical model. For this purpose, a hydraulic model was created from the range of the river in which the bridge is located in the software by using field data. Then, by entering the data on the scouring of the bridge bases for the discharge of 25 to 1850 m3/s with different time steps, the effect of change of flow discharge on the scour around the middle and lateral piers of the bridge was investigated. The results of numerical model show a trend The increase was such that in low to moderate discharges (329m3/s) the scouring rate around the middle piers had the highest value, but in high discharges and flood conditions the scurry in the right support had the highest value, also up to 1630 m3/s flood conditions, the scouring rate in the left support had the lowest value, which was due to the morphology of the river bed and the Conditions are the creation of secondary currents in the arc.
Research Article
civil engineering
Mohammad Hossein Taghizadeh Valdi; Edris Merufinia
Abstract
In this article, the water entry problem of reticulated pounder including 4, 9, 16, 25 and 64 holes which are distributed with a matrix arrangement on the surface of the pounder, is investigated numerically and to model the interaction between the pounder and fluid, an explicit dynamic analysis was employed ...
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In this article, the water entry problem of reticulated pounder including 4, 9, 16, 25 and 64 holes which are distributed with a matrix arrangement on the surface of the pounder, is investigated numerically and to model the interaction between the pounder and fluid, an explicit dynamic analysis was employed using the Eulerian-Lagrangian couple formulation available in the commercial finite element software Abaqus 6.14-2. The results of the numerical solution were validated by comparing and matching the numerical, theoretical and experimental results of the trajectory of a spherical projectile in the depth of water, including the shape of the air bubble formed and the pinch-off time and depth, which indicated the accuracy and application of the numerical algorithm used. The results of the current research showed that the 9-hole pounder reaches the model bed at a depth of 100 cm in less time than other pounders with different arrangement and number of holes. In 16- and 25-hole pounders, the ratio between the mass of the pounder and the area of the holes is unstable, and due to the decrease in the area of the holes, the effect of water resistance on the bottom of the pounder increases when it moves in its depth. The effect of increasing the mass of the pounder on reducing the duration of its immersion in the water depth is more evident in the 64-hole pounder. So that this pounder has a smaller area of holes compared to other pounders, it has more mass with smaller holes than other pounders, and despite the smaller dimensions of the holes and the increase in the life of the reticulated pounder, which is the factor that increases the resistance of the water entering the pounder floor, due to the large mass of the pounder, it overcomes the water resistance that is applied as an upward force on the bottom of the reticulated pounder, and the duration of its movement in the depth of the water is reduced from the moment it hits the free surface of the water until it reaches the model bed.
Research Article
مدیریت ساخت و مدیریت پروژه
Amir Hossein Dalir; Hasan Javanshir
Abstract
This study evaluates the impact of Digital Twin (DT) technology on project success metrics—specifically time, cost, quality, and safety—within the automated monitoring and control of construction projects. Employing a mixed-methods approach, the research integrates survey data, Structural ...
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This study evaluates the impact of Digital Twin (DT) technology on project success metrics—specifically time, cost, quality, and safety—within the automated monitoring and control of construction projects. Employing a mixed-methods approach, the research integrates survey data, Structural Equation Modeling (SEM), case analysis, and qualitative insights from interviews and focus groups. A novel DT-based Progress Monitoring Management Model (DRX) is proposed and assessed, leveraging reality capture and Extended Reality (XR) technologies to streamline construction oversight. Findings reveal that DT significantly improves project outcomes by automating process oversight. The DRX model emerges as an innovative framework, enhancing construction management through the integration of DT and XR technologies, offering empirical insights into its efficacy and delineating its practical challenges and advantages.
Research Article
management
ali beiruti
Abstract
In Genaveh city, due to the absence of a desirable urban governance model, most programs have been top-down, leading to the undesirability of urban plans and schemes. The aim of this research is to enhance the indicators of good urban governance through the explanation of the Citizen's House model ...
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In Genaveh city, due to the absence of a desirable urban governance model, most programs have been top-down, leading to the undesirability of urban plans and schemes. The aim of this research is to enhance the indicators of good urban governance through the explanation of the Citizen's House model and approach in Genaveh and its extension to cities with a population of less than 100,000. Initially, the eight indicators of participation, efficiency and effectiveness, political stability, access to information, social justice, accountability, community-oriented, and legality were examined and evaluated using a combined analytical-quantitative and qualitative method. The research data was collected through library and field research methods. The target population was approximately 34,286 individuals, and the sample size was determined to be 384 using Cochran's formula. The indicators of good urban governance were analyzed using planning models and techniques such as TOPSIS and Fuzzy Vikor. The research findings and analytical test results indicate that the examined indicators are in an undesirable state and there is a need to improve their qualitative level in the neighborhoods of Genaveh city. The ranking results of the neighborhoods indicate variations in the level of governance across different areas. Finally, the Citizen's House approach was proposed in accordance with the conditions of Genaveh, with the aim of implementing it in Genaveh city first and then extending it to cities with a population of less than 100,000.
Research Article
management
Alireza Khedri
Abstract
The purpose of this research is to explain the proper urban governance model with emphasis on social capital (case study of Bushehr city). The statistical population includes a number of citizens of Bushehr city. From this number, according to Cochran's formula, 384 people were selected as a statistical ...
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The purpose of this research is to explain the proper urban governance model with emphasis on social capital (case study of Bushehr city). The statistical population includes a number of citizens of Bushehr city. From this number, according to Cochran's formula, 384 people were selected as a statistical sample. After interviewing expert professors and reviewing sources, the objective questionnaire of urban meritocracy was prepared. This questionnaire was considered as a research tool. After verifying the content validity of the items, several people were asked to answer the questionnaire and identify the incomprehensible phrases and words. The purpose of this work was to find out the possible problems of the test. After this test, the form of some items was changed, but no item was deleted. Research data was analyzed using spss24 software. Also, Amos25 software was used for confirmatory factor analysis. The method used to check the reliability of the questionnaire was Cronbach's alpha. According to the findings, it was found that the dimensions of the appropriate urban governance variables and social capital have a significant relationship. That is, the better the governance of Bushehr city according to the activists, the more the social capital of the activists in Bushehr city will be felt by the citizens.
Research Article
Civil Engineering
MohammadHossein Edalatkhah
Abstract
The aim of this research is to identify and rank the effects of Corona virus on the construction industry. To achieve this goal, library studies and analytical methods such as the fuzzy decision matrix and the use of expert questionnaires have been used. In this research, the most important effects of ...
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The aim of this research is to identify and rank the effects of Corona virus on the construction industry. To achieve this goal, library studies and analytical methods such as the fuzzy decision matrix and the use of expert questionnaires have been used. In this research, the most important effects of Corona virus have been examined according to criteria such as the probability of occurrence, the severity of the effect, and the probability of detection, and then they have been analyzed using the opinion of experts and analytical tools like Fuzzy Vikor Solver software. The results show that the most effective effects of Corona virus on the construction industry include things such as lack of housing, delays in projects and schedules, reduced economic development due to the suspension of construction activities, reduced demand for building structures, unemployment of daily income workers, financial losses to construction companies, and reduced employment. In the construction industry, increasing the financial risks of contractors, the possibility of non-compliance with organizational obligations, and creating psychological problems such as depression on unemployed workers and employees.
