Iranian Society of Structural Engineering (ISSE)Journal of Structural and Construction Engineering2476-39779520220723Improving the Project Risk Management Process in Construction Projects by Provide a Suggested Method Based on PMBOK Standard and SHAMPU ModelImproving the Project Risk Management Process in Construction Projects by Provide a Suggested Method Based on PMBOK Standard and SHAMPU Model51914033010.22065/jsce.2021.263171.2317FAReza Mohajeri Borje GhalehPh.D. Student in Engineering and Construction Management, Department of Civil Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran0000-0001-7516-9706Towhid PourrostamAssistant Professor, Department of Civil Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran0000-0002-3981-4111Naser Mansour ShariflooAssociate Professor, Department of Civil Engineering, Central Tehran Branch, Islamic Azad University, Tehran, IranJavad Majrouhi SardroudAssistant Professor, Department of Civil Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran0000-0003-4037-5782Ebrahim SafaAssistant Professor, Department of Civil Engineering, South Tehran Branch, Islamic Azad University, Tehran, IranJournal Article20201225Construction projects involve many groups with different goals, which each of them is exposed to many risks. In practice, different project stakeholders have different understandings of project risks. Each of which identifies and analyzes project risks without relying on a common methodology. For this reason, in most construction projects, discussing project risks and decision-making based on risk is a common problem that causes differences between project parties. Therefore, risk management in construction projects is a fundamental challenge. This research has been formed to improve the project risk management process with emphasis on construction projects; and use library resources, has investigated and compared the risk sub-processes in the models presented after 1990. By identifying the strengths and weaknesses of different models, a new method of risk management has been proposed. The proposed method consists of a combination of the PMBOK standard and the SHAMPU model and supports sub-processes that have received less attention in models, such as project definition, decision-making based on benefit/cost and Implementation Management. The addition of these sub-processes has been due to the specific nature of construction projects. These sub-processes can assess risks in more detail than existing models, and effectively help the project stakeholders to achieve a common understanding of risks in identifying and analyzing project risks.Construction projects involve many groups with different goals, which each of them is exposed to many risks. In practice, different project stakeholders have different understandings of project risks. Each of which identifies and analyzes project risks without relying on a common methodology. For this reason, in most construction projects, discussing project risks and decision-making based on risk is a common problem that causes differences between project parties. Therefore, risk management in construction projects is a fundamental challenge. This research has been formed to improve the project risk management process with emphasis on construction projects; and use library resources, has investigated and compared the risk sub-processes in the models presented after 1990. By identifying the strengths and weaknesses of different models, a new method of risk management has been proposed. The proposed method consists of a combination of the PMBOK standard and the SHAMPU model and supports sub-processes that have received less attention in models, such as project definition, decision-making based on benefit/cost and Implementation Management. The addition of these sub-processes has been due to the specific nature of construction projects. These sub-processes can assess risks in more detail than existing models, and effectively help the project stakeholders to achieve a common understanding of risks in identifying and analyzing project risks.https://www.jsce.ir/article_140330_0f68b217965d6cadfab4a62f4df27468.pdfIranian Society of Structural Engineering (ISSE)Journal of Structural and Construction Engineering2476-39779520220723Progressive collapse in steel moment frame structures: multi-parameter studyProgressive collapse in steel moment frame structures: multi-parameter study203814003610.22065/jsce.2021.279072.2403FAEsmaeil Mohammadi DehcheshmehPh.D. Candidate, School Civil Eng., Iran University of science and Technology, Tehran, Iran0000-0002-8092-9084Mohammad KamalizadPh.D. Candidate, School Civil Eng., Yazd University, Yazd, IranVahid BroujerdianAssistant Professor, School Civil Eng., Iran University of science and Technology, Tehran, Iran0000-0003-3454-4797Gholamreza Ghodrati AmiriProfessor, School Civil Eng., Iran University of science and Technology, Tehran, IranJournal Article20210331Progressive collapse due to unexpected accidents usually begins with the collapse of one of the main members of the structures, such as a column or a load-bearing wall. The collapse expands the entire structure by creating additional loads on the members and connections attached to the collapsed member. In this research, various scenarios of single-column-removal (5 cases) and double -column-removal (6 cases) in 4, 8 and 12-story structures with steel moment frames were investigated in OpenSees software. The simulation was done in a 3D macro-modeling manner. The nonlinear behavior of materials and geometry were taken into account. Moreover, the vertical effects of the composite floors were considered as double-line springs at the beam to column joints. The results showed that the structures are vulnerable to progressive collapse. According to the results, as the number of stories of the structure decreases the damage caused to the structure is increases. In this regard, the displacements occurred in the corner single-column-removal (Scenario 1) were 70, 56 and 51 mm for 4, 8 and 12 story structures, respectively. The double-column-removal compared to single-column removal greatly increases the structural damage. So that in an 8-story structure, the ratio of maximum displacement of the corner double-column-removal (Scenario 11) compared to the corner single-column-removal (Scenario 1) is equal to 3.7. Furthermore, the impact of the composite floor in the single- and double-column-removal scenarios can reduce the vertical displacements by 40% and 60%, respectively. Finally, the joist beams direction in the composite floor can be effective in reducing the vertical displacements.Progressive collapse due to unexpected accidents usually begins with the collapse of one of the main members of the structures, such as a column or a load-bearing wall. The collapse expands the entire structure by creating additional loads on the members and connections attached to the collapsed member. In this research, various scenarios of single-column-removal (5 cases) and double -column-removal (6 cases) in 4, 8 and 12-story structures with steel moment frames were investigated in OpenSees software. The simulation was done in a 3D macro-modeling manner. The nonlinear behavior of materials and geometry were taken into account. Moreover, the vertical effects of the composite floors were considered as double-line springs at the beam to column joints. The results showed that the structures are vulnerable to progressive collapse. According to the results, as the number of stories of the structure decreases the damage caused to the structure is increases. In this regard, the displacements occurred in the corner single-column-removal (Scenario 1) were 70, 56 and 51 mm for 4, 8 and 12 story structures, respectively. The double-column-removal compared to single-column removal greatly increases the structural damage. So that in an 8-story structure, the ratio of maximum displacement of the corner double-column-removal (Scenario 11) compared to the corner single-column-removal (Scenario 1) is equal to 3.7. Furthermore, the impact of the composite floor in the single- and double-column-removal scenarios can reduce the vertical displacements by 40% and 60%, respectively. Finally, the joist beams direction in the composite floor can be effective in reducing the vertical displacements.https://www.jsce.ir/article_140036_9471fd852e1538770cdb449b21dcf1a6.pdfIranian Society of Structural Engineering (ISSE)Journal of Structural and Construction Engineering2476-39779520220723Analytical Model for Applying the Effect of Prying Force in the Design of Bolted ConnectionsAnalytical Model for Applying the Effect of Prying Force in the Design of Bolted Connections395713990810.22065/jsce.2021.299927.2533FASoheil Alipour SajediPh.D. Candidate, Civil Eng. Dept., Faculty of Engineering, , University of Urmia, Urmia, IranMohammad Reza SheidaiiProfessor, Civil Eng. Dept., Faculty of Engineering, , University of Urmia, Urmia, Iran0000-0002-9606-0205Yousef HosseinzadehAssociate Professor, Structural Eng. Dept., Faculty of Civil Engineering, , University of Tabriz, Tabriz, Iran0000-0003-4764-5458Journal Article20210815Prying action in bolted beam-to-column connections may cause brittle failure due to increasing the bolt force to a value greater than its design strength. In the most common design methods, the prying force is generally determined using analytical models. Existing analytical models are based on the research for the bolted connections with rolled T-stubs. In the end plate connections, the T-stub is fabricated by the complete joint penetration welding of steel plates. In this research, an analytical model is proposed for determining the prying force in built-up T-stubs. For this purpose, three specimens were tested under monotonic loading to determine the load-displacement relationship and the load-carrying capacity of T-stubs. An advanced non-linear finite element model was established to evaluate the load-carrying capacity of the bolted T-stubs, and it was validated using the experimental data. A parametric study was performed to evaluate the effects of geometric and mechanical properties of the connections on the magnitude and location of the prying force resultant, the eccentricity of the bolt force, and the location of plastic hinges. Consequently, a formula was proposed to determine the location of the prying force resultant. It was shown that a plastic hinge is formed at a distance of about 10 mm from the T-stub web. Also, it was shown that the eccentricity of the bolt force reduces the nominal capacity of the bolt by about 35%. With these data, a simplified analytical model was developed to predict the T-stub load-carrying capacity assuming the location determined for the bolt force, prying force, and plastic hinge. The magnitude of prying force and T-stub load-carrying capacity were determined using the proposed model. The results showed that by using the proposed model, an average of 10.6% improvement in the accuracy of the bolted T-stub load-carrying capacity determination is achieved.Prying action in bolted beam-to-column connections may cause brittle failure due to increasing the bolt force to a value greater than its design strength. In the most common design methods, the prying force is generally determined using analytical models. Existing analytical models are based on the research for the bolted connections with rolled T-stubs. In the end plate connections, the T-stub is fabricated by the complete joint penetration welding of steel plates. In this research, an analytical model is proposed for determining the prying force in built-up T-stubs. For this purpose, three specimens were tested under monotonic loading to determine the load-displacement relationship and the load-carrying capacity of T-stubs. An advanced non-linear finite element model was established to evaluate the load-carrying capacity of the bolted T-stubs, and it was validated using the experimental data. A parametric study was performed to evaluate the effects of geometric and mechanical properties of the connections on the magnitude and location of the prying force resultant, the eccentricity of the bolt force, and the location of plastic hinges. Consequently, a formula was proposed to determine the location of the prying force resultant. It was shown that a plastic hinge is formed at a distance of about 10 mm from the T-stub web. Also, it was shown that the eccentricity of the bolt force reduces the nominal capacity of the bolt by about 35%. With these data, a simplified analytical model was developed to predict the T-stub load-carrying capacity assuming the location determined for the bolt force, prying force, and plastic hinge. The magnitude of prying force and T-stub load-carrying capacity were determined using the proposed model. The results showed that by using the proposed model, an average of 10.6% improvement in the accuracy of the bolted T-stub load-carrying capacity determination is achieved.https://www.jsce.ir/article_139908_754c3dddf4811f4d6efe49e8ff01bc2e.pdfIranian Society of Structural Engineering (ISSE)Journal of Structural and Construction Engineering2476-39779520220723Applying neural networks for estimating the compressive strength of confined circular concrete columns with FRP sheetsApplying neural networks for estimating the compressive strength of confined circular concrete columns with FRP sheets587714003410.22065/jsce.2021.178649.1825FAYaser MoodiDept. of Civil Engineering, Univ. of Sistan and Baluchestan, Zahedan, IranEhsan EslamiDept. of Computer Engineering, Velayat University, Iranshahr, IranSeyed Roohollah MousaviAssistant Professor, Dept. of Civil Engineering, Univ. of Sistan and Baluchestan0000-0002-8936-9378Babak DizangianDept. of Civil Engineering, Velayat University, Iranshahr, Iran0000-0001-5400-5411Hamid MirshekarDept. of Civil Engineering, Univ. of semnanJournal Article20190414Most of existing reinforced concrete columns are in need of retrofitting and strengthening for various reasons, including errors during the construction phase, changing the type of applications in structures, changes in design codes, occurrence of strong beam-weak column mechanism and the damages due to natural disasters. One of the most common ways of strengthening the columns is the confinement of the reinforced concrete columns. So far, several experiments have been conducted on concrete columns confined with fibre-reinforced polymer sheets and the results show that the use of fibre-reinforced polymer sheets increases the compressive strength of the concrete columns effectively. Different models in order to determine the compressive strength of the fibre-reinforced-polymer-confined concrete columns are provided in the previous researches. In this study, a large set of experimental data regarding circular columns confined with different types of FRP has been collected. Two neural network prediction methods were also used for determining the compressive strength of the confined circular columns with FRP sheets. These methods are back propagation (BP) and radial basis functions (RBF). Finally, the defined neural networks were examined with the available estimation models based on four standard error testing criteria. Results show that the neural networks could estimate the compressive strength of the confined columns with FRP with more accuracy rather than the existing analytical models.Most of existing reinforced concrete columns are in need of retrofitting and strengthening for various reasons, including errors during the construction phase, changing the type of applications in structures, changes in design codes, occurrence of strong beam-weak column mechanism and the damages due to natural disasters. One of the most common ways of strengthening the columns is the confinement of the reinforced concrete columns. So far, several experiments have been conducted on concrete columns confined with fibre-reinforced polymer sheets and the results show that the use of fibre-reinforced polymer sheets increases the compressive strength of the concrete columns effectively. Different models in order to determine the compressive strength of the fibre-reinforced-polymer-confined concrete columns are provided in the previous researches. In this study, a large set of experimental data regarding circular columns confined with different types of FRP has been collected. Two neural network prediction methods were also used for determining the compressive strength of the confined circular columns with FRP sheets. These methods are back propagation (BP) and radial basis functions (RBF). Finally, the defined neural networks were examined with the available estimation models based on four standard error testing criteria. Results show that the neural networks could estimate the compressive strength of the confined columns with FRP with more accuracy rather than the existing analytical models.https://www.jsce.ir/article_140034_70df6345c28d1ce447ab87ff17182b25.pdfIranian Society of Structural Engineering (ISSE)Journal of Structural and Construction Engineering2476-39779520220723Evaluation of structural health monitoring system in reducing the cost of maintenance and repair of buildings in high seismic areasEvaluation of structural health monitoring system in reducing the cost of maintenance and repair of buildings in high seismic areas789314004110.22065/jsce.2021.290663.2473FASepideh RahimiIslamic Azad university of Nour branch0000-0002-5194-8841Journal Article20210614Today, the structural health monitoring system based on various non-destructive analysis and tests has been greatly expanded in order to better performance and prevent further damage to the structure especially in areas with high seismicity. Given that, various structural health monitoring systems have been introduced. On the other hand, the discussion of maintenance costs with these methods can be helpful in choosing the most optimal method for this purpose. To this end, five new systems for health monitoring of structures, including the method of examining changes in basic information; Finite element model upgrade method, acoustic and ultrasonic method, magnetic field method and thermal field method were selected in 5 categories: management, technical, economic, human source and safety along with 20 sub-criteria in the field of maintenance. Then, through the pairwise comparison questionnaire of analytic hierarchy process method and receiving the opinions of experts in this field, different structural health monitoring systems were evaluated and prioritized to select the optimal system based on the most important criteria of building maintenance. The results showed that the structural health monitoring system by finite element model method has gained the first rank in all 5 main factors of management, technical, economic, human source and safety.Today, the structural health monitoring system based on various non-destructive analysis and tests has been greatly expanded in order to better performance and prevent further damage to the structure especially in areas with high seismicity. Given that, various structural health monitoring systems have been introduced. On the other hand, the discussion of maintenance costs with these methods can be helpful in choosing the most optimal method for this purpose. To this end, five new systems for health monitoring of structures, including the method of examining changes in basic information; Finite element model upgrade method, acoustic and ultrasonic method, magnetic field method and thermal field method were selected in 5 categories: management, technical, economic, human source and safety along with 20 sub-criteria in the field of maintenance. Then, through the pairwise comparison questionnaire of analytic hierarchy process method and receiving the opinions of experts in this field, different structural health monitoring systems were evaluated and prioritized to select the optimal system based on the most important criteria of building maintenance. The results showed that the structural health monitoring system by finite element model method has gained the first rank in all 5 main factors of management, technical, economic, human source and safety.https://www.jsce.ir/article_140041_618880cb310e93b86a4b2c78539b9d19.pdfIranian Society of Structural Engineering (ISSE)Journal of Structural and Construction Engineering2476-39779520220723Experimentally and Analytically Investigating Effect of Confinement on Behavior of RC Beams Reinforced by GFRPExperimentally and Analytically Investigating Effect of Confinement on Behavior of RC Beams Reinforced by GFRP9410614004010.22065/jsce.2021.254770.2283FAMahmoud-Reza Hposseini-TabatabaeiCivil Engineering depatrtment0000-000302361-0189Hossein Ali RahdarFaculty Member, Faculty of Engineering, Zabol University0000-0002-2794-4242Seyed Roohollah MousaviAssistant Professor, Dept. of Civil Engineering, Univ. of Sistan and Baluchestan0000-0002-8936-9378Seyyed Mostafa TabatabaeiDepartment of Civil Engineering, Islamic Azad University of Zahedan, Zahedan, IranJournal Article20201102Glass Fiber Reinforced Polymer (GFRP) rebars have high tensile strength and high resistance against corrosion. This study addressed the investigation of the confining effects of the transverse steel rebars on concrete beams reinforced using GFRP rebars. For this purpose, six beam specimens with cross-section dimensions of 20 and 30 cm and a span length of 200 cm were constructed. The rebars had cross-section area values of 1.7, 2.6, and 3.5 times the balance value. The middle of three beams was reinforced using stirrups with small spacing. These specimens were called confined beams. The specimens were tested under four-point static loading. The behavior of the unconfined and confined specimens was evaluated using the parameters of the initial yield strength, the stiffness of the cracking part, the ultimate load, and the ductility index. The experimental results indicate that confining the beams by steel stirrups increased the first three behavioral parameters to about 35, 27, and 29 percent, respectively. The ductility index for the two samples, having the longitudinal rebars of 2.6 and 3.5 times the balanced amount, decreased by about 6 and 22 percent. The other sample's ductility index increased approximately 6 percent compared to the control samples. Moreover, the capacities of both unconfined and confined specimens are estimated by existing analytical relationships with an error of 5 to 16 percent, having good agreements with the experimental results.<br /><br /><br /><br /><br /><br />.Glass Fiber Reinforced Polymer (GFRP) rebars have high tensile strength and high resistance against corrosion. This study addressed the investigation of the confining effects of the transverse steel rebars on concrete beams reinforced using GFRP rebars. For this purpose, six beam specimens with cross-section dimensions of 20 and 30 cm and a span length of 200 cm were constructed. The rebars had cross-section area values of 1.7, 2.6, and 3.5 times the balance value. The middle of three beams was reinforced using stirrups with small spacing. These specimens were called confined beams. The specimens were tested under four-point static loading. The behavior of the unconfined and confined specimens was evaluated using the parameters of the initial yield strength, the stiffness of the cracking part, the ultimate load, and the ductility index. The experimental results indicate that confining the beams by steel stirrups increased the first three behavioral parameters to about 35, 27, and 29 percent, respectively. The ductility index for the two samples, having the longitudinal rebars of 2.6 and 3.5 times the balanced amount, decreased by about 6 and 22 percent. The other sample's ductility index increased approximately 6 percent compared to the control samples. Moreover, the capacities of both unconfined and confined specimens are estimated by existing analytical relationships with an error of 5 to 16 percent, having good agreements with the experimental results.<br /><br /><br /><br /><br /><br />.https://www.jsce.ir/article_140040_77cac6031614047d6c1f795b194f2697.pdfIranian Society of Structural Engineering (ISSE)Journal of Structural and Construction Engineering2476-39779520220723Semi-active control of three-story benchmark structure using LQG algorithm with a fuzzy-genetic systemSemi-active control of three-story benchmark structure using LQG algorithm with a fuzzy-genetic system10712314003510.22065/jsce.2021.234410.2164FAHossein Fazaeli Hosseini NejadPh.D. Candidate in Structural Engineering, Faculty of Engineering, Department of Civil Engineering, Ferdowsi
University of Mashhad, Mashhad, IranAbbas KaramodinAssociate Professor, Department of Civil Engineering, Ferdowsi University of Mashhad, Mashhad, IranJournal Article20200608Damages of natural disasters such as earthquakes has led engineering sciences to research and expand the use of earthquake-resistant systems. Semi-active control systems have been considered due to their ability to change the mechanical properties of their system and the use of limited energy sources. On the other hand, taking advantage of soft computing and fuzzy inference systems due to the compensation for existing uncertainties, considerably helps to reduce structure’s responses during earthquakes. In this paper, a method for controlling a three-story nonlinear benchmark structure equipped with an MR magnetic damper is presented. The required voltage of the damper is obtained from the design of a LQG linear control system with a fuzzy inference system. In this system, the linear control force of LQG and the force of the previous step of the damper enter the Takaki-Sugeno fuzzy system and the desired voltage of the damper is obtained. In order to optimize the controller performance, the rules of the fuzzy inference system are taught by a genetic algorithm. Modeling of the damper is based on the Bouc-wen model. The results of the evaluation criteria and time history charts show the high efficiency of the proposed controller in reducing seismic responses against other proposed systemsDamages of natural disasters such as earthquakes has led engineering sciences to research and expand the use of earthquake-resistant systems. Semi-active control systems have been considered due to their ability to change the mechanical properties of their system and the use of limited energy sources. On the other hand, taking advantage of soft computing and fuzzy inference systems due to the compensation for existing uncertainties, considerably helps to reduce structure’s responses during earthquakes. In this paper, a method for controlling a three-story nonlinear benchmark structure equipped with an MR magnetic damper is presented. The required voltage of the damper is obtained from the design of a LQG linear control system with a fuzzy inference system. In this system, the linear control force of LQG and the force of the previous step of the damper enter the Takaki-Sugeno fuzzy system and the desired voltage of the damper is obtained. In order to optimize the controller performance, the rules of the fuzzy inference system are taught by a genetic algorithm. Modeling of the damper is based on the Bouc-wen model. The results of the evaluation criteria and time history charts show the high efficiency of the proposed controller in reducing seismic responses against other proposed systemshttps://www.jsce.ir/article_140035_9bd71474396f481959f03aac08e0bfab.pdfIranian Society of Structural Engineering (ISSE)Journal of Structural and Construction Engineering2476-39779520220723Evaluating of Effective Factors in Sustainable Development of Dilapidated Neighborhoods in Karaj and Presenting Management Solutions (Case study: District 1 of Karaj)Evaluating of Effective Factors in Sustainable Development of Dilapidated Neighborhoods in Karaj and Presenting Management Solutions (Case study: District 1 of Karaj)12413914003910.22065/jsce.2021.299209.2524FABahador FarazmandDepartment of civil engineering, karaj branch, Islamic Azad UniversityZahra SabziDepartment of civil engineering, karaj branch, Islamic Azad UniversityJournal Article20210811Sustainable development considers the use of endogenous capabilities in urban areas, local groups and communities as social capitals that have an important role in maintaining and developing the metropolises. Local development in the form of a popular process has been emphasized as the focus of sustainable urban development programs and metropolitan areas. In this study, considering the indexes of sustainable districts development as one of the main concerns of developing communities, a model in relation to the district one of Karaj city is presented. The Promethee method, which is one of the multi-criteria decision-making methods used to select the optimal and preferred options. Critic method, which is very consistent with multi-criteria decisions, used to weigh the criteria. The questionnaires distributed among experts have 8 main criteria of participation, identity and vitality, social justice, satisfaction, safety and security, environment, urban landscape and developmental characteristics and include 34 sub-criteria and 5 options which was ‘Islamabad’, ‘Bahar’, ‘Azimiyeh’, ‘North Taleghani’ and ‘Baraghan’ district. The results of advantages and disadvantages analyses showed that ‘Azimiyeh’ has the best condition and then, ‘North Taleghani’, ‘Bahar’, ‘Baraghan’ and ‘Islamabad’ are in the next ranks, respectively. In addition, critical sub-criteria have been identified in each district. Finally some general and detailed suggestions and solutions have been proposed to promote districts. These results can be used as a model for the sustainable development of urban decay by relevant agencies, including ministries, municipalities and etc.Sustainable development considers the use of endogenous capabilities in urban areas, local groups and communities as social capitals that have an important role in maintaining and developing the metropolises. Local development in the form of a popular process has been emphasized as the focus of sustainable urban development programs and metropolitan areas. In this study, considering the indexes of sustainable districts development as one of the main concerns of developing communities, a model in relation to the district one of Karaj city is presented. The Promethee method, which is one of the multi-criteria decision-making methods used to select the optimal and preferred options. Critic method, which is very consistent with multi-criteria decisions, used to weigh the criteria. The questionnaires distributed among experts have 8 main criteria of participation, identity and vitality, social justice, satisfaction, safety and security, environment, urban landscape and developmental characteristics and include 34 sub-criteria and 5 options which was ‘Islamabad’, ‘Bahar’, ‘Azimiyeh’, ‘North Taleghani’ and ‘Baraghan’ district. The results of advantages and disadvantages analyses showed that ‘Azimiyeh’ has the best condition and then, ‘North Taleghani’, ‘Bahar’, ‘Baraghan’ and ‘Islamabad’ are in the next ranks, respectively. In addition, critical sub-criteria have been identified in each district. Finally some general and detailed suggestions and solutions have been proposed to promote districts. These results can be used as a model for the sustainable development of urban decay by relevant agencies, including ministries, municipalities and etc.https://www.jsce.ir/article_140039_8525d765d326c9c069d20b4ec72e12fb.pdfIranian Society of Structural Engineering (ISSE)Journal of Structural and Construction Engineering2476-39779520220723Energy-based analysis of a steel moment frame with viscous damper under blast loadingEnergy-based analysis of a steel moment frame with viscous damper under blast loading14016214015810.22065/jsce.2021.268835.2338FAMohammad Javad GoodarziDepartment of civil engineering, technical and vocational university, tehran, iranHossein NajafiDeputy of Sari MunicipalityMajid Moradinoshivani0000-0002-8470-6160Journal Article20210116The degree of control of the response and performance of structures under external loads is one of the most important issues in structural and earthquake engineering. Today, the use of modern systems to control structural vibrations has expanded significantly. Viscous dampers are one of the most common tools for controlling structural vibrations against external loads. One of these foreign burdens could be an explosion caused by terrorist attacks. In this research, it has been tried to investigate the behavior of structures with viscous dampers based on energy balance under explosion load. For this aim, two 10-story structures with Moment Resistance Frame (MRF) system and steel Moment Resistance Frame with viscous damper under different explosion scenarios have been analyzed and the dissipated and absorbed energies in the energy balance due to external work have been evaluated. First, to better understand the behavior of these structures, the performance of the structures is evaluated based on the plastic hinges and the relative displacement of the studied stories and finally the effect of viscous damper in reducing the damage of structures using energy balance concepts. The results show that in general, viscous dampers can reduce the damage to an acceptable level and control the behavior of the structure.The degree of control of the response and performance of structures under external loads is one of the most important issues in structural and earthquake engineering. Today, the use of modern systems to control structural vibrations has expanded significantly. Viscous dampers are one of the most common tools for controlling structural vibrations against external loads. One of these foreign burdens could be an explosion caused by terrorist attacks. In this research, it has been tried to investigate the behavior of structures with viscous dampers based on energy balance under explosion load. For this aim, two 10-story structures with Moment Resistance Frame (MRF) system and steel Moment Resistance Frame with viscous damper under different explosion scenarios have been analyzed and the dissipated and absorbed energies in the energy balance due to external work have been evaluated. First, to better understand the behavior of these structures, the performance of the structures is evaluated based on the plastic hinges and the relative displacement of the studied stories and finally the effect of viscous damper in reducing the damage of structures using energy balance concepts. The results show that in general, viscous dampers can reduce the damage to an acceptable level and control the behavior of the structure.https://www.jsce.ir/article_140158_f610d96901eb5c1b8d217d7944b3dc58.pdfIranian Society of Structural Engineering (ISSE)Journal of Structural and Construction Engineering2476-39779520220723The effect of initial compression on the interface of repair/concrete and the evaluation of the compressive strength of mortarsThe effect of initial compression on the interface of repair/concrete and the evaluation of the compressive strength of mortars16317914003810.22065/jsce.2021.252708.2260FAAli Saberi VaezanehPh.D , Department of Civil Engineering, Imam Khomeini International University, Qazvin, Iran0000-0003-0921-6484Mahmood NaderiProfessor, Department of Civil Engineering, Imam Khomeini International University, Qazvin, IranJournal Article20201013One of the key factors that reduce the bond strength between repair mortars and concrete substrate is improper compaction of the repair layer when applied to concrete. Due to the fact that compacting has a direct effect on the adhesion of the interface of two layers, so the lack of proper compaction causes small cavities between the two layers and as a result causes a decrease in bond strength. Therefore, in this paper, by applying semi-destructive tests, by applying initial compression for 24 hours on the mortar applied to the concrete substrate, the effect of compression on bond between the repair layer and the concrete has been studied. The effect of one week of curing on the dry shrinkage of repair mortars is also presented. In the following, the compressive strength of repair mortars was evaluated using the "twist-off" and "pull-off" tests. In this regard, calibration diagrams were drawn between laboratory tests and semi-destructive tests and linear equations were presented to convert the original results from semi-destructive tests to the compressive strength of mortars. ABAQUS software was used to investigate cracks and stresses in mortars. The results show an increase in bond strength between the repair mortar and the concrete substrate by applying initial compression. Applying initial compression of 0.5 kg/cm2 on unhardened mortar increased the shear and tensile strength between the repair and concrete layers at the age of 90 days by 36.9% and 31.4%, respectively. Also, a linear relationship with high correlation was observed between the readings obtained from the above tests with the compressive strength of repair mortars.One of the key factors that reduce the bond strength between repair mortars and concrete substrate is improper compaction of the repair layer when applied to concrete. Due to the fact that compacting has a direct effect on the adhesion of the interface of two layers, so the lack of proper compaction causes small cavities between the two layers and as a result causes a decrease in bond strength. Therefore, in this paper, by applying semi-destructive tests, by applying initial compression for 24 hours on the mortar applied to the concrete substrate, the effect of compression on bond between the repair layer and the concrete has been studied. The effect of one week of curing on the dry shrinkage of repair mortars is also presented. In the following, the compressive strength of repair mortars was evaluated using the "twist-off" and "pull-off" tests. In this regard, calibration diagrams were drawn between laboratory tests and semi-destructive tests and linear equations were presented to convert the original results from semi-destructive tests to the compressive strength of mortars. ABAQUS software was used to investigate cracks and stresses in mortars. The results show an increase in bond strength between the repair mortar and the concrete substrate by applying initial compression. Applying initial compression of 0.5 kg/cm2 on unhardened mortar increased the shear and tensile strength between the repair and concrete layers at the age of 90 days by 36.9% and 31.4%, respectively. Also, a linear relationship with high correlation was observed between the readings obtained from the above tests with the compressive strength of repair mortars.https://www.jsce.ir/article_140038_2e50554d661f14d16aab344dd310164c.pdfIranian Society of Structural Engineering (ISSE)Journal of Structural and Construction Engineering2476-39779520220723Investigation of the behavior of overburden reinforced concrete bridges under the relative motion of normal fault ruptureInvestigation of the behavior of overburden reinforced concrete bridges under the relative motion of normal fault rupture18019314003710.22065/jsce.2021.306577.2591FAAli SalimiPhD Candidate, Department of Civil Engineering, School of Engineering, Islamic Azad University Nour Branch, Nour, IranMohamad HoseinzadehAssistant Professor, Department of Civil Engineering, School of Engineering, Islamic Azad University Nour Branch, Nour, IranMorteza Hosseinali BeygiAssistant Professor, Department of Civil Engineering, Babol Noshirvani University of Technology, Babol, Iran0000-0003-3839-6891Sepideh RahimiAssistant Professor, Department of Civil Engineering, School of Engineering, Islamic Azad University Nour Branch, Nour, IranJournal Article20210925The construction of urban infrastructure structures such as bridges, tunnels, etc. located on the fault line is inevitable in many cases. Therefore, various solutions have been proposed to reduce the damage to national vital arteries. In this research, grid caisson foundations have been used for the bridge foundation system to reduce the destructive effects of fault propagation. First, the three-dimensional finite element numerical model was validated using experimental models. By comparing the deformation of the ground surface due to normal fault between the numerical and laboratory models, a maximum difference of 5% was observed, which had a good agreement. Then, a parametric study was performed to influence the parameters such as foundation thickness, foundation stiffness, relative position of the foundation relative to the fault outcrop, and the connection of the bridge slab deck on the overall performance of the bridge. The results of numerical studies showed that mat foundation cannot meet the overall stability of the bridge under normal fault. The grid caisson system had better performance. This system was able to withstand large tectonic deformations. Indeterminate of the structure has caused negative effects on the elements of the structure. While reducing the degrees of structural indetermination, it reduces the stress on the pier members and the deck of the bridge slab. The use of loose sandy soils resulted in more contact of the foundation with the subsoil, and its differential settlement was less than in the case where dense sandy soils were used.The construction of urban infrastructure structures such as bridges, tunnels, etc. located on the fault line is inevitable in many cases. Therefore, various solutions have been proposed to reduce the damage to national vital arteries. In this research, grid caisson foundations have been used for the bridge foundation system to reduce the destructive effects of fault propagation. First, the three-dimensional finite element numerical model was validated using experimental models. By comparing the deformation of the ground surface due to normal fault between the numerical and laboratory models, a maximum difference of 5% was observed, which had a good agreement. Then, a parametric study was performed to influence the parameters such as foundation thickness, foundation stiffness, relative position of the foundation relative to the fault outcrop, and the connection of the bridge slab deck on the overall performance of the bridge. The results of numerical studies showed that mat foundation cannot meet the overall stability of the bridge under normal fault. The grid caisson system had better performance. This system was able to withstand large tectonic deformations. Indeterminate of the structure has caused negative effects on the elements of the structure. While reducing the degrees of structural indetermination, it reduces the stress on the pier members and the deck of the bridge slab. The use of loose sandy soils resulted in more contact of the foundation with the subsoil, and its differential settlement was less than in the case where dense sandy soils were used.https://www.jsce.ir/article_140037_cbc2ba77a45ab4f77d47dee5a10a7d8a.pdfIranian Society of Structural Engineering (ISSE)Journal of Structural and Construction Engineering2476-39779520220723Identifying the influential components of organizational managers' behavior on reducing claims in construction projectsIdentifying the influential components of organizational managers' behavior on reducing claims in construction projects21319414015910.22065/jsce.2021.281304.2423FAYaghoub AlipouriAssistant Professor, Department of Construction Engineering and Management, Faculty of Civil Engineering, K. N. Toosi University of Technology, Tehran, Iran.Seyed Ali Taheri DurakiMSc. Graduated, Department of Project Management, Faculty of Architecture, Alaoddoleh Semnani Institute of Higher Education, Garmsar, Iran.Journal Article20210415Identifying and managing the factors affecting the claim reduction of stakeholders can help a lot to achieve the goals of a project and an organization. Researchers have identified these factors from different perspectives, but so far seldom research has identified the influential components of organizational managers' behavior on reducing claims in construction projects. Current study aims to identify these behavioral components and provide effective strategies to reduce conflicts. The present study is applied and descriptive and is a field study in terms of purpose and data collection, respectively. The data collection tools are library studies, interviews and questionnaires and the statistical population of the research is project managers, professors and experts in the field of management and engineers working on projects. Library studies were conducted to identify the behavioral components of organizational managers and Delphi interviews were conducted with 18 experts to complete these components. Due to the infinite number of members of the community, the Cochran's infinite formula was used to calculate the number of sample members which calculated to be 196. To investigate the effect of the behavioral components of organizational managers on claim reduction, a structured-questionnaire was distributed among the sample members. To check the validity of the questionnaire, the content validity method was used with the opinion of experts and its reliability was confirmed by Cronbach's alpha of 0.872. Testing the hypotheses was done using the "binomial test" in SPSS20 software. According to the findings, more than 95% of the participants believed that the behavioral components of manager’s ethics, personality, fair judgment, performance, openness and responsibility, flexibility and agility, organizational culture, behavioral style, courage, explaining transparency, no lying and no hypocrisy, motivational behavior and lack of indifference play a prominent role in reducing conflicts and claims in construction projects.Identifying and managing the factors affecting the claim reduction of stakeholders can help a lot to achieve the goals of a project and an organization. Researchers have identified these factors from different perspectives, but so far seldom research has identified the influential components of organizational managers' behavior on reducing claims in construction projects. Current study aims to identify these behavioral components and provide effective strategies to reduce conflicts. The present study is applied and descriptive and is a field study in terms of purpose and data collection, respectively. The data collection tools are library studies, interviews and questionnaires and the statistical population of the research is project managers, professors and experts in the field of management and engineers working on projects. Library studies were conducted to identify the behavioral components of organizational managers and Delphi interviews were conducted with 18 experts to complete these components. Due to the infinite number of members of the community, the Cochran's infinite formula was used to calculate the number of sample members which calculated to be 196. To investigate the effect of the behavioral components of organizational managers on claim reduction, a structured-questionnaire was distributed among the sample members. To check the validity of the questionnaire, the content validity method was used with the opinion of experts and its reliability was confirmed by Cronbach's alpha of 0.872. Testing the hypotheses was done using the "binomial test" in SPSS20 software. According to the findings, more than 95% of the participants believed that the behavioral components of manager’s ethics, personality, fair judgment, performance, openness and responsibility, flexibility and agility, organizational culture, behavioral style, courage, explaining transparency, no lying and no hypocrisy, motivational behavior and lack of indifference play a prominent role in reducing conflicts and claims in construction projects.https://www.jsce.ir/article_140159_8117b86bf7bfe112ac9e85d3203db227.pdf