Mostafa Pourhosein zakariaee; Saeed Faridnia
Volume 1, Issue 1 , June 2019, , Pages 1-9
mostafa mahdikhani
Volume 1, Issue 2 , July 2019, , Pages 10-25
Abstract
In today's world, we are witnessing the launch, maintenance, control and exploitation of various projects. Projects that have high costs and optimal use of this capital in the current economy of the country are highly regarded by managers. On the other hand, each project is expected to achieve its predetermined ...
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In today's world, we are witnessing the launch, maintenance, control and exploitation of various projects. Projects that have high costs and optimal use of this capital in the current economy of the country are highly regarded by managers. On the other hand, each project is expected to achieve its predetermined goals at a specified time. Today, the necessity of rapid construction of subway lines in Tehran's metropolitan area, which is involved in severe traffic jams, is not covered by anyone. Despite the understanding of this issue by the authorities and the good actions taken so far in this direction. However, more effort and a greater determination to reach the acceptable speed in the construction and completion of metro lines is necessary. Quick implementation of projects is based on the principles of concurrent engineering, called fast tracking, in construction projects. In the fast delivery method, solutions such as resource enhancement, synchronous engineering, overlapping phases, value engineering, teamwork by the multi-functional team, improving communication and information transfer, and accelerating decision making, using efficient contractual methods (transferring risks as Effective way, which by using the correct methods, accelerates the implementation of the project. Therefore, in this article, management strategies for implementing fast tracking projects in the development projects of the country have been investigated.
Seyed Saeid Tabatabaei; Seyed hamid moafi madani
Volume 1, Issue 3 , August 2019, , Pages 10-28
Abstract
Due to the complexity of loads applied to wharves and piers because of their special application as mooring and berthing structures, their design always has many challenges. These structures have a large mass, and the piles and pile caps connections must sustain large inelastic deformations during major ...
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Due to the complexity of loads applied to wharves and piers because of their special application as mooring and berthing structures, their design always has many challenges. These structures have a large mass, and the piles and pile caps connections must sustain large inelastic deformations during major earthquakes which force-based design method cannot consider properly. So this study was undertaken to evaluate the full seismic performance of a typical synchrolift wharf located at Hormozgan province with performance-based design method by a series of static pushover analyses for three different hazard levels in accordance with ASCE/COPRI 61-14 code requirements and local seismicity. Soil-structure interaction, material overstrength, and site-specific response spectra were used to determine the displacement demands. The results reveal that using conventional force-based design method leads to the unreliable deck as well as uneconomical pile foundation designs.
behnam bashir; Ghasem Omidvar; Mehdi Ravanshadnia
Volume 1, Issue 6 , December 2019, , Pages 10-24
Abstract
One of the hallmarks of any country's economic development is the completion of development plans optimally at the lowest cost and most profit.The goal of success in residential projects is to reduce costs and time, increase quality and customer satisfaction. The method of data collection was library-based. ...
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One of the hallmarks of any country's economic development is the completion of development plans optimally at the lowest cost and most profit.The goal of success in residential projects is to reduce costs and time, increase quality and customer satisfaction. The method of data collection was library-based. Then, by reviewing the research background and interviewing the contractors, the factors affecting the success of Mehr Housing Projects were investigated. Residents were also considered important factors in their view. This set of data was analyzed to determine the factors affecting the success of these projects and then the importance of each of these indicators and their correlation was shown in the success of these projects in order to develop a proposal for future housing projects such as Present a national action plan to achieve their success. Outputs from the statistical analysis of this study show that from the contractors' point of view, indicators such as project financing guidelines, labor supply, materials and machinery, senior management support, and project team members qualifications. , The presence of responsible, experienced and expert people Employer idleness is more important in issuing approvals and approvals and enforcing contractual obligations. Also, from the point of view of residents, features such as timely delivery, consideration of project site conditions in natural disasters (floods, storms, etc.) provide Making the necessary divisions, adapting the infrastructure to the family population, and ease of access are more important.
Atefeh Khodabakhshi; Ali Hooshmand; Faezeh Nejati
Volume 1, Issue 4 , September 2019, , Pages 11-26
Abstract
ر, [07.09.19 13:30] Thousands of people around the world die each year due to accidents involving safety management. With the development of construction projects in recent years, unfortunately, the statistics of work accidents and injuries and injuries in the country are increasing day by day in developing ...
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ر, [07.09.19 13:30] Thousands of people around the world die each year due to accidents involving safety management. With the development of construction projects in recent years, unfortunately, the statistics of work accidents and injuries and injuries in the country are increasing day by day in developing countries including Iran where safety and health programs Still in their infancy or lacking in performance, the situation is more critical. Developing countries are seeing significant growth in development projects. Factors in the safety management system were identified in a systematic, scientifically based way, followed by a number of people working on water and wastewater through questioning. The letter you are looking for. After collecting the responses, the results were categorized by contractors, technical and safety experts, consultants, employers and insurance companies. The first group is from the perspective of site supervisor contractors by multiple senior managers and providing adequate and adequate resources, the second group is from the perspective of consultants with the right to terminate work in breach of safety, the third group is from the employer's perspective considering the owner's safety to be implemented safely. Projects require that the fourth group, from the perspective of Barzai insurance companies, introduce ongoing projects as one of the most important steps affecting the safety management system in projects.
Shabnam Alihassani; Ahmad Edalatpanah
Volume 1, Issue 5 , October 2019, , Pages 11-22
Abstract
The main purpose of the present study is to investigate the impact of external factors on risk management in construction companies (case study in Hormozgan province). The research method was descriptive correlational. The statistical population includes engineers working on active projects, specialists ...
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The main purpose of the present study is to investigate the impact of external factors on risk management in construction companies (case study in Hormozgan province). The research method was descriptive correlational. The statistical population includes engineers working on active projects, specialists and experts in Hormozgan province with a total of 120 people, Due to the limited number of the statistical population, all individuals were considered as the sample, but in multiple follow-up, 5 completed questionnaires were collected and statistically exploited. The research tool was a 36-item questionnaire developed and validated by Khaksar et al. One-way regression and Friedman tests were used to analyze the research hypotheses through SPSS / 23 software. The results showed that external factors influence the risk management of construction companies and there was a significant difference between the mean ratings of external factors affecting risk management in construction companies. The highest mean score was for the construct items and the lowest was for the job position items. In fact, the factors of tenure were: construction factor, economic and financial factor, administrative and organizational factor, social and cultural factor, technical and technological factor and job position factor in risk management in construction companies.
Mohammad Sahraei karambasti; hassan divandari; behnam abolfathi
Volume 1, Issue 7 , December 2019, , Pages 11-26
Abstract
Solid waste is one of the problems of urban management. Total solid municipal waste on the Earth in the last year was 1.3 billion tones, increasing every year. Waste management and the strategy of its application is one of the major concerns in most countries. Landfill and waste incineration are two ...
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Solid waste is one of the problems of urban management. Total solid municipal waste on the Earth in the last year was 1.3 billion tones, increasing every year. Waste management and the strategy of its application is one of the major concerns in most countries. Landfill and waste incineration are two essential solutions for solid waste disposal in the world. Lack of proper land, high cost, multiple strict rules, public opposition to the construction of landfills and environmental pollution are the factors make researchers prefer waste incineration instead of land fill. Municipal solid waste incineration is one of the most environmentally friendly practices can significantly reduce the volume of household waste by up to 90% so it plays an important role in the environment. The products of this method are fly ash and bottom ash of incinerated wastes in incineration plants. In early 1970s reports on the use of municipal solid waste ash in asphalt was issued. In 1980s a number of asphalt centered projects included municipal solid waste ash was done. The purpose of this study is to optimize the use of municipal solid waste ash and prevent environmental damage and expand landfills. In this study, the possibility of using fly ash as an admixture for asphalt bitumen and pavement substrates was investigated and the results showed that it is possible to use fly ash and incinerated bottom ash as substituted materials such as filler or fine particles for asphalt aggregation and has a great impact on improving the physical and chemical properties of asphalt and will also be effective in solving landfill problems.
hossein sheikhhassani; Saghar Ghaemi bidgoli
Volume 1, Issue 8 , January 2020, , Pages 11-19
Abstract
Thermal assessment of extensive green roofs
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Thermal assessment of extensive green roofs
Samira Shokati Gourabi
Volume 1, Issue 9 , February 2020, , Pages 11-17
Abstract
This article aims to provide insights into the importance of managers' skills in project management success and a lack of emphasis in this area within university education. In this talk, many prominent writers will discuss the human or "soft" skills needed in project management. Against this background, ...
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This article aims to provide insights into the importance of managers' skills in project management success and a lack of emphasis in this area within university education. In this talk, many prominent writers will discuss the human or "soft" skills needed in project management. Against this background, a review of how to equip project management literature and university education with potential project managers in the field of human skills will be conducted. . As the PMBOK guide is the most important of the texts offered in project management training, this article will highlight that "hard (technical)" skills emphasize the need for cost in "soft" skills. The following discussion illustrates the need for a balance between hard and soft skills in project management training in universities. The result suggests that teachers in this field should recognize the importance of incorporating more human skills aspects into their curricula.
Mahdi Babazadeh
Volume 1, Issue 10 , March 2020, , Pages 11-20
Abstract
normally , the risk allocation process is carried out by the owner in the bidding documents ; it causes him to assign responsibility to the contractor without considering the fair conditions of the present factors in the contract . on the other hand , due to lack of knowledge of project characteristics ...
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normally , the risk allocation process is carried out by the owner in the bidding documents ; it causes him to assign responsibility to the contractor without considering the fair conditions of the present factors in the contract . on the other hand , due to lack of knowledge of project characteristics and organizational capabilities , it is generally suggested that an inappropriate contract structure is proposed by the owner of the project . this mismatch , or lack of awareness of the range of responsibility , will certainly lead to a decrease in the likelihood of achieving the project performance goals . therefore , investigating appropriate risk allocation methods such as participation for project success is essential . therefore , it is suggested to adopt a fair , participatory and win - win attitude towards the regulation of contract provisions . the results show a clear relationship between the form of contract and also the agreement in risk management in projects . so those problems that support initial participation of actors and create opportunities for free and non - liberal talk will lead to a more efficient risk management process
milad arjomand; nima sadeghiyan; sahar amini
Volume 2, Issue 1 , April 2020, , Pages 11-17
Abstract
The main purpose of this paper is to evaluate and estimate the annual rainfall return period and provide the best statistical distribution. Therefore, the annual rainfall data of Karaj Synoptic Station has been used to estimate the rainfall with a return period of 200,100,50,25,5. Gift tests (x ̅), ...
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The main purpose of this paper is to evaluate and estimate the annual rainfall return period and provide the best statistical distribution. Therefore, the annual rainfall data of Karaj Synoptic Station has been used to estimate the rainfall with a return period of 200,100,50,25,5. Gift tests (x ̅), Rss, K-S were used to use the best statistical distribution and finally smada software was used to analyze the selected distribution. The results of the study show that among the statistical distributions used in this study, the distribution of the lognormal is the most appropriate distribution.
Somayeh Ghorbani Noe
Abstract
As projects grow and develop and become more complex, new tools are needed to help manage projects. One of these tools is risk management, because in an unstable and uncertain environment, one can expect Out-of-schedule and unexpected events at any time. Experts' knowledge is often used to assess the ...
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As projects grow and develop and become more complex, new tools are needed to help manage projects. One of these tools is risk management, because in an unstable and uncertain environment, one can expect Out-of-schedule and unexpected events at any time. Experts' knowledge is often used to assess the risk of projects, but humans always use words and phrases in their conversations that have no clear boundaries. Fuzzy logic is used to deal with such ambiguous words and phrases. Fuzzy set theory is a method that has proven effective in managing uncertainties similar to those mentioned in construction projects. A fuzzy expert system is an expert or knowledge-based system that uses a set of fuzzy membership functions and rules to reason data instead of binary logic. For systems with high uncertainty where sufficient and accurate information is not available, the fuzzy approximation reasoning approach is proposed. Fuzzy system input can be inaccurate information and system processing is done using approximate reasoning. In this study, the risks in construction projects were investigated by obtaining the opinions of experts in the fields of clients, consultants and contractors. By providing steps, we have tried to identify risks, evaluate them, and control high-priority risks using fuzzy logic and expert systems.
Mohammad Alidousti; Mohammad Reza Farzad Behtash; Alireza Estelaji
Abstract
Statement of Problem: The city of Tehran as a political, social and economic capital has a decisive role in the fate of the country. Tehran with a population of more than 8 million people is the 24th most populous city in the world. 8.10% of the population has a share equal to 21% of the country's gross ...
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Statement of Problem: The city of Tehran as a political, social and economic capital has a decisive role in the fate of the country. Tehran with a population of more than 8 million people is the 24th most populous city in the world. 8.10% of the population has a share equal to 21% of the country's gross domestic product (GDP) and more than 50% of tax revenues as well as 55% of bank deposits are provided from the city and province of Tehran. At the same time, the city still suffers from many problems, the most important of which is the unfavorable situation of builders, to the extent that according to the same study and a survey of construction industry experts in Tehran, 42.5% of them consider the quality of construction in Tehran poor or catastrophic. Dilapidated and dysfunctional structures in the heart of Tehran and with very difficult accesses add to the concern about possible crises. Although several programs have been carried out in the field of repair and renovation of worn-out structures, but so far the city administration has not met expectations and we still face this problem. The purpose of this study is to introduce the effective first steps to create a codified method (planning) for implementation so that the results can guarantee the quality of ongoing construction. The research method was descriptive and correlational and a questionnaire was used for this purpose. The statistical population is the target of professional engineers of Tehran Building Engineering Organization. 120 questionnaires were analyzed by SPSS and SmartPLS software. Based on the findings of this study, the use of six important factors in planning, including: implementation of construction quality assurance insurance, mandatory contractor in construction, accurate and complete implementation of the building technical certificate, adjustment and increase of engineers' fees along with increasing public awareness and change and Amend national building regulations. According to the findings of this study, it can be said that the most important finding of this study is that the process necessary to establish insurance quality assurance of the builder is clearly explained.
Rahim Hajibagheri; Amirhossein Bazaee; Roozbeh Aghamajidi
Abstract
The phenomenon of flood, in spite of all its complexities, can be studied and appropriate solutions can be sought to control and reduce its damage and even economic exploitation of floods. On the other hand, before constructing any hydraulic structure such as dams, overflows, diversion channels, temporary ...
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The phenomenon of flood, in spite of all its complexities, can be studied and appropriate solutions can be sought to control and reduce its damage and even economic exploitation of floods. On the other hand, before constructing any hydraulic structure such as dams, overflows, diversion channels, temporary dams, etc., it is necessary to have the information of maximum possible flood and flood hydrograph with different return periods in order to estimate the magnitude of different floods and predicted the maximum height of the river flood zone, the maximum area and width of the river flood in different areas, the maximum flow velocity, changes in shear stress, flood volume, changes in landing number and hydraulic radius, etc. flood routing and zoning operations or quantifying river confluence for flood alert systems. in this study, by selecting the case of Sivand river in fars province in the specified time period, flood frequency analysis was performed with the help of Smada and Easyfitt software and the maximum flood discharge was determined with different return periods. then, by selecting tangbolaghi hydrometric station as the representative station of Sivand river, hydraulic flood routing and zoning operations were attempted by Mike11 computer model.
Civil Engineering
Morvarid Hajian; Reza Attarnejad
Abstract
This paper presents an exact formula for considering soil stiffness under the foundation. This formula derived from a 3D modeling of eight strip footings with different foundation widths supported on a soil medium. In the case of an earthquake, the behavior of the substructure soil plays an important ...
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This paper presents an exact formula for considering soil stiffness under the foundation. This formula derived from a 3D modeling of eight strip footings with different foundation widths supported on a soil medium. In the case of an earthquake, the behavior of the substructure soil plays an important role in the response of the structure. Studies show that the dynamic response spectrum of a structure on a flexible foundation is different from the response spectrum of a structure on a rigid foundation. Hence it is important to model the soil medium correctly to reach the best seismic results. There are different methods for modeling soil-structure interaction. These models use a constant value for modeling the soil stiffness. However, the soil stiffness varies along the foundation and should be calculated by analytical studies. This paper provides a simple formula which shows a non-uniform soil stiffness under the strip foundation and can be used for practical purposes.
Mohamadamin Mirbagheri; Hasan Javanshir; Majid Safehian
Abstract
Today, smart buildings, which combine sensors and actuators, allow owners to save energy, increase security, provide users with information about their work environment, and operate directly on the building via the Internet. Indoor environmental parameters such as temperature, humidity, lighting, and ...
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Today, smart buildings, which combine sensors and actuators, allow owners to save energy, increase security, provide users with information about their work environment, and operate directly on the building via the Internet. Indoor environmental parameters such as temperature, humidity, lighting, and air quality are monitored by IoT sensors in smart buildings. In this paper, we propose a smart building solution for managing the indoor environment based on the Internet of Things, which aims to provide functions such as monitoring the environmental parameters of the room and detecting the number of users in the space. It is also a cloud platform where virtual entities collect data obtained by sensors and cloud virtual entities perform data analysis tasks using system learning algorithms. This cloud platform also includes a control dashboard for managing and controlling the building. The goal of this article is to define, develop, and present the results of a project that uses sensors in a standard business center to monitor and condition business units using Internet of Things technologies. The arrangement and location of the sensors are explained in this study, followed by the sensors used, wireless interfaces, and cloud technologies. The project results are presented using Bluemix and Node Red.
Naeim Banisaeid; Nematollah Jafarzadeh Haghighi Fard
Abstract
Background and Objective: Freshwater salinization in the world occurs during man-made urban and industrial activities. These activities range from groundwater abstraction for drinking water in coastal areas to the level at which seawater overflows with fresh water to de-hardening processes in industrial ...
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Background and Objective: Freshwater salinization in the world occurs during man-made urban and industrial activities. These activities range from groundwater abstraction for drinking water in coastal areas to the level at which seawater overflows with fresh water to de-hardening processes in industrial use to prevent damage to facilities. Materials and Methods: In this research, using the study of reference books as well as internet search, with google search engine, in databases of springer, science direct, online library wiley, iwap online, etc., articles related to biological treatment of saline wastewater, checked. Results: The results show that the performance of bacterial metabolism, among other factors, depends on the ambient osmotic pressure, which is closely related to the concentration of salt in the mineral liquid. High salt concentration has direct and indirect effects on bacterial activity and this will have a significant impact on the capacity to use biological processes in saline wastewater put. Conclusion: The best way to treat this type of wastewater is to use halophilic bacteria that are less sensitive to salt additions. Phosphorus removal and nitrogen oxidation are more sensitive to the removal of organic matter in these wastewaters. In general, according to studies, the use of combined anaerobic-aerobic process can create a higher efficiency in the treatment of such wastewater, provided that if the amount of salt is added to more than 12% of halophilic bacteria is added to the system.
roozbeh aghamajidi; amir abbas kamanbedast
Abstract
The discussion of earthworks and irrigation and drainage projects is very important from a technical and economic point of view. In the Southwest Khuzestan pipeline project with 230 kilometers of G.R.P. pipes, it is effective to provide the volume of earth materials for earthling around the pipe and ...
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The discussion of earthworks and irrigation and drainage projects is very important from a technical and economic point of view. In the Southwest Khuzestan pipeline project with 230 kilometers of G.R.P. pipes, it is effective to provide the volume of earth materials for earthling around the pipe and also earthling to ensure the depth of the trench before trenching. Due to the presence of sand materials in the region, in this research, these materials were used in earthworks around the pipe in different ways, including compaction by compactor and also compaction by flooding method, and the results showed that it is possible to use sand materials with fine grains less than He compacted 12% in the form of flooding and up to a density of 85%. Also, in order to provide the depth of the trench, you can mix sand materials with different percentages of clay so that the percentage of different salts such as gypsum, sulfate, and chlorine is reduced and the specific weight of the clay is increased. Different methods of moistening soil materials were compared in order to provide optimal moisture, including moistening at the borrow site and on the road. The effect of humidity on the density of soils with different grain sizes was also compared. The results showed that in clay materials, if the moisture content is more than 3% less than the optimum moisture content, it is difficult to compensate it by tamping. In the earthen layers made with fine-grained materials, traffic has a more negative effect on the density of the layer. The coarser the materials, the less impact traffic and passage of time will have. Also, the study of cross-sections showed that in sandy fields, the best way to protect the roads from the influx of quicksand is to follow the natural slope of the land as much as possible and to avoid earthmoving or earthmoving at a high height as much as possible.
Amirreza Maleki; Reza Amin; Ali Khodaii
Abstract
Nowadays, the close competition of airline companies in attracting passengers has made it very important for planners and policymakers in this field to investigate the psychological issues and the differences in the passengers' views. Different airline companies seek to examine the ideals and values ...
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Nowadays, the close competition of airline companies in attracting passengers has made it very important for planners and policymakers in this field to investigate the psychological issues and the differences in the passengers' views. Different airline companies seek to examine the ideals and values of passengers in order to identify their strengths and weaknesses in order to maintain their position in the competitive market or promote it with correct and accurate planning. In this study, various factors affecting satisfaction from the passengers' point of view are examined using survey data and logistic regression modeling. The factors examined in this study include characteristics such as age and gender, loyalty to the airline, and the level of satisfaction with the quality of various services such as food and internet services, baggage handling services, and online ticket booking. In addition, the effect of variables related to each flight, such as distance and delays, are also investigated on passenger satisfaction. The modeling results of this research show the importance and significance of the variables of type of travel (personal or business), type of passenger (loyal or not loyal to the company), class of travel (Eco or Eco Plus or business), the level of satisfaction with baggage handling and the level of satisfaction with the boarding process. This study has shown the high sensitivity of passengers to the process of getting on the plane and also to baggage handling.
Civil Engineering
Abolfazl Yosefi; Hashem Jahangir
Abstract
Concrete can be assumed as the most regular constructional material in the world, which has a lot of advantages as well as disadvantages that attracted the attention of researchers. Adding natural materials including silica fume, fly ash, rice husk ash, metakaolin, and natural fibers and animal waste ...
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Concrete can be assumed as the most regular constructional material in the world, which has a lot of advantages as well as disadvantages that attracted the attention of researchers. Adding natural materials including silica fume, fly ash, rice husk ash, metakaolin, and natural fibers and animal waste to concrete can improve the fresh and hardened properties of concrete such as slump, strength, water absorption, and durability, and at the same time reduce the environmental effects. On the other hand, adding too many natural additives can cause adverse effects on concrete, such as reducing efficiency and increasing curing time, which can be compensated by adding different kinds of fibers to the concrete mixture. In order to add natural additives to concrete, several experimental and field tests were performed, in which the effects of natural additives on the properties of concrete and their long-term performance were evaluated. Reducing the carbon footprint, and increasing resistance to cracking and corrosion are among the advantages of natural additives. In this paper, a review was conducted to evaluate the influence of natural additives on the mechanical properties of concrete specimens including compressive strength, flexural strength, and water absorption. The overall effects of utilizing natural additives on concrete properties were reviewed and listed accordingly.
Ehsan Mohsenian Fard; Meysam Memar; Davood Ghaedian
Abstract
Concrete and rebars should have a good bond behavior so that there is no slip between rebars and concrete under the service loads. On the other hand, one of the major disadvantages of steel bars is their vulnerability to corrosion. Covering bars as a solution is also costly and cannot be implemented ...
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Concrete and rebars should have a good bond behavior so that there is no slip between rebars and concrete under the service loads. On the other hand, one of the major disadvantages of steel bars is their vulnerability to corrosion. Covering bars as a solution is also costly and cannot be implemented in all projects. So one of the most suitable alternative methods is the use of GFRP bars. Other ways to compensate for the weakness of the concrete tensile strength as well as its low ductility are the use of different fibers. Concrete with polypropylene fibers is highly ductiled compared to conventional concrete and is completely scattered in concrete and creates isotropetic conditions and can prevent cracks. Therefore, in this study, the effect of polypropylene fibers on concrete compressive strength and bonding strength between concrete and GFRP rebar was investigated experimentally. For this purpose, the amount of this type of fiber is selected 0.15, 0.30 and 0.45 % volume of concrete, and 15cm cubic concrete samples were made in three types of 350, 400 and 450 grade and were cured at 7- and 28-day ages. In this study, the rebar diameter of GFRP was chosen 8 mm and rebars were embedded inside the concrete in a length five times the rebar diameter, and 28-day concrete samples were tested through pull-out and compressive resistance tests. Finally, the compressive strength of the samples and the force-time curves from the pull-out test were assessed. Average compressive strength values, slump values, maximum force and other important parameters were discussed. The results showed that the bond resistance between the polypropylene fiber-reinforced concrete and GFRP rebar increased with the increase in the amount of fibers. Adding fibers also has a relatively good effect on enhancement of the compressive strength of the concrete.
feridoon asadi
Volume 1, Issue 2 , July 2019, , Pages 37-43
Abstract
The first studies to choose contractors in EPC contracts are back in the years ahead. Studies have shown that the existence of a contractor in EPC contracts is considered to be important for contractors and reduces risk, cost, and overall improvement of project objectives. General contractors have limited ...
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The first studies to choose contractors in EPC contracts are back in the years ahead. Studies have shown that the existence of a contractor in EPC contracts is considered to be important for contractors and reduces risk, cost, and overall improvement of project objectives. General contractors have limited workload in specialized disciplines and it is inefficient to take full-time specialized labor force and carry out the operation, maintenance and control of specialized machinery with a high cost for them. As a result, contractors in EPC contracts that specialize in one or more specific fields of activity will be able to perform specialized work at a lower cost and higher quality. This research, using two qualitative and quantitative approaches, identifies and prioritizes selection criteria for contractors, which was done through interviewing AHP and topsis methodology. The results indicated that 12 factors such as executive, financial and engineering teams are involved in contractor selection in EPC contracts.
Mohammad Reza Asadi
Volume 1, Issue 3 , August 2019, , Pages 39-56
Abstract
The importance of using concrete as the main material in the construction of structures seems obvious. Due to the high cost of repairs, their durability is of particular importance. Permeability is the most important factor in reducing the durability of structures so that resistance to concrete permeability ...
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The importance of using concrete as the main material in the construction of structures seems obvious. Due to the high cost of repairs, their durability is of particular importance. Permeability is the most important factor in reducing the durability of structures so that resistance to concrete permeability is the first factor in determining the service life of a structure. . Since long time, researchers and civil engineers and metallurgists have been looking for additives to help them improve the mechanical properties of concrete and have made many successes. In addition to additives such as nano, the effect of exterior materials such as polyurethane paint on the durability of concrete can be investigated. Replacing part of the cement with filler material has been the idea of many recent studies. Numerous reports indicate the use of these materials to improve the mechanical properties of concrete. Most attention has been focused on the use of silica. The aim of this study was to investigate the effect of polyurethane paint on self-compacting concrete containing methacrylene and silica on durability of concrete used in structures.
somayeh sirouspour; Mansour Parvizi; Mohsen Zahed aqae
Volume 1, Issue 5 , October 2019, , Pages 45-57
Abstract
The present study has mainly focused on the modification of the hyperbolic model formulation so that the shortcomings of the said model can be corrected and more conformity with the experimental results can also be provided. This model, also known as Duncan-Chang model, is a two parameter model for obtaining ...
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The present study has mainly focused on the modification of the hyperbolic model formulation so that the shortcomings of the said model can be corrected and more conformity with the experimental results can also be provided. This model, also known as Duncan-Chang model, is a two parameter model for obtaining the stress-strain curve of the triaxial test. The hyperbolic model which is indicative of the ideal characteristics of the soil is particularly advantageous in that it does not require the presence of extensive test programs and can easily be implemented through computer programs. As the results show, although numerous studies have already been carried out to address the model shortcomings, this model fails to predict the plastic behavior of the subsaturated soils. Among the shortcomings of the said model are the insufficiency of the hyperbolic model relations for the analysis of the stage related to the soil instability, uselessness of the relations in case of soil volume variation, experimental nature of the used coefficients in the relation. Hyperbolic relations are useful in solving different problems of engineering and geotechnics since numerical values of hyperbolic model parameters can be extracted from the experimental results and all the relations that are used for the drained soils can also be applied to non-drained and unstable soils. Furthermore, numerous values of parameters have been tested and utilized for different kinds of soil over the past thirty years. Therefore, a rich source is available for comparison and interpretation of the obtained results from different projects.
nasser abootaleb; Mona Alizadeh Giashi
Volume 1, Issue 1 , June 2019, , Pages 10-18
Abstract
Failure and buckling in shell structures, including silos, can be created for various reasons such as distortion, defects created during construction, defects created during operation, or environmental factors, etc. Silos can be subjected to a variety of lateral and axial loads, but since they are in ...
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Failure and buckling in shell structures, including silos, can be created for various reasons such as distortion, defects created during construction, defects created during operation, or environmental factors, etc. Silos can be subjected to a variety of lateral and axial loads, but since they are in fact affected by the combination of these loads, silos behave under the influence of composite loads. The silos in this research are hot-rolled and located on the ground. The variables of this research are type and scope of defect. Silos are also evaluated in semi-filled and semi-solid state. The model silos were analyzed in ANSYS software. The radial radial neural network RBF was used to predict the buckling capacity of the cylindrical shells. The results of this study indicate that artificial neural networks are a good tool for predicting buckling capacity of silos with defects.
