Pub Date : 2021-06-26DOI: 10.22059/CEIJ.2020.293429.1634
M. Komasi, B. Beiranvand
The rapid drawdown condition to control floods and irrigation is one of the things that may occur over the lifetime of the dam. Also, the stability of the dam at the rapid drawdown will be more important due to the faster reduction of the water level of the dam reservoir than the pore water pressure. In this study, the finite element method and software GeoStudio used to study the seepage from the body earth dam. Also, the complete elastic-plastic model of Mohr-Coulomb is considered in the analysis. In this study, the stability analysis of the Eyvshvan earth dam after rapid drawdown due water to release of the dam reservoir to downstream agricultural lands during drought crisis is investigated. For the validation, first, the results of the pore water pressure instrument were compared with the results of numerical analysis. The results of multivariate regression analysis (coefficient of determination) show very good agreement of about R2=0.98. The results show that the phreatic line remains after 29 days from the start of the rapid drawdown of the reservoir, while half of the volume of the drained reservoir remains at 1842 (1/3 of the crest). The analysis of dam stability during rapid drawdown using both Morgenstern-Price and Bishop Methods showed that the most critical situation would occur after 42 days of discharge with a factor of safety (FoS) of 1.71, with no stability hazard and the upstream slope would be safe.
{"title":"Seepage and Stability Analysis of the Eyvashan Earth Dam under Drawdown Conditions","authors":"M. Komasi, B. Beiranvand","doi":"10.22059/CEIJ.2020.293429.1634","DOIUrl":"https://doi.org/10.22059/CEIJ.2020.293429.1634","url":null,"abstract":"The rapid drawdown condition to control floods and irrigation is one of the things that may occur over the lifetime of the dam. Also, the stability of the dam at the rapid drawdown will be more important due to the faster reduction of the water level of the dam reservoir than the pore water pressure. In this study, the finite element method and software GeoStudio used to study the seepage from the body earth dam. Also, the complete elastic-plastic model of Mohr-Coulomb is considered in the analysis. In this study, the stability analysis of the Eyvshvan earth dam after rapid drawdown due water to release of the dam reservoir to downstream agricultural lands during drought crisis is investigated. For the validation, first, the results of the pore water pressure instrument were compared with the results of numerical analysis. The results of multivariate regression analysis (coefficient of determination) show very good agreement of about R2=0.98. The results show that the phreatic line remains after 29 days from the start of the rapid drawdown of the reservoir, while half of the volume of the drained reservoir remains at 1842 (1/3 of the crest). The analysis of dam stability during rapid drawdown using both Morgenstern-Price and Bishop Methods showed that the most critical situation would occur after 42 days of discharge with a factor of safety (FoS) of 1.71, with no stability hazard and the upstream slope would be safe.","PeriodicalId":43959,"journal":{"name":"Civil Engineering Infrastructures Journal-CEIJ","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42164728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-01DOI: 10.22059/CEIJ.2021.291862.1625
S. R. Massah, H. Ahmadi
The fundamental concepts of biogeography-based optimization (BBO), a meta-heuristic algorithm, have been inspired by the geographical distribution of animals. This algorithm does not need a starting point, and performs a random search instead of a gradient-based search. In this article, for the first time, the weights of 2D and 3D trusses with specific geometries and different stress and displacement constraints have been optimized by using the BBO approach. Also, in this work, the numerical results achieved by other researchers through various optimization techniques have been compared with the results obtained from the Particle Swarm Optimization (PSO), Differential Evolution (DE) and BBO algorithms. It has been demonstrated that the search and exploration capability of the BBO algorithm is superior to that of the DE and PSO algorithms, and that it achieves better results than the other optimization techniques considered in this paper. This superiority is due to the excellent exploration capability of the BBO algorithm and the fact that it achieves a favorable optimal solution in the initial iteration.
{"title":"Weight Optimization of Truss Structures by the Biogeography-Based Optimization Algorithms","authors":"S. R. Massah, H. Ahmadi","doi":"10.22059/CEIJ.2021.291862.1625","DOIUrl":"https://doi.org/10.22059/CEIJ.2021.291862.1625","url":null,"abstract":"The fundamental concepts of biogeography-based optimization (BBO), a meta-heuristic algorithm, have been inspired by the geographical distribution of animals. This algorithm does not need a starting point, and performs a random search instead of a gradient-based search. In this article, for the first time, the weights of 2D and 3D trusses with specific geometries and different stress and displacement constraints have been optimized by using the BBO approach. Also, in this work, the numerical results achieved by other researchers through various optimization techniques have been compared with the results obtained from the Particle Swarm Optimization (PSO), Differential Evolution (DE) and BBO algorithms. It has been demonstrated that the search and exploration capability of the BBO algorithm is superior to that of the DE and PSO algorithms, and that it achieves better results than the other optimization techniques considered in this paper. This superiority is due to the excellent exploration capability of the BBO algorithm and the fact that it achieves a favorable optimal solution in the initial iteration.","PeriodicalId":43959,"journal":{"name":"Civil Engineering Infrastructures Journal-CEIJ","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45396163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-01DOI: 10.22059/CEIJ.2021.291231.1619
M. Tajdini, M. Bargi, Omid Rasouli Ghahroudi
Soil cement is a mixture of Portland cement, soil and water, in which hydration of cement and compaction causes the materials’ constituents to bond together makes a dense and durable composition with low permeability and abrasion resistant. Since most of the recent researches are focused on the addition of nano-SiO2 on concrete, in this paper it has been attempted to use nano-SiO2 particles in soil-cement and observe the effects. Due to the fact that in concrete there are no particles passing sieve 200 and this restriction does not apply to soil-cements, some tests were carried out on the nano-SiO2 + soil-cement matrix because of the meaningful difference between concrete and soil-cement. The test procedure consists of moisture-dry density, unconfined compressive test and hydraulic conductivity. In these tests, silica fume (with specific surface area of 21 m2/g), nano-SiO2 (with specific surface area of 200 and 380 m2/g) were added to soil-cement. The results show that adding certain amounts of nano-SiO2 particles to the soil-cement matrix can improve the compressive strength and reduce permeability and speed hydration reactions in the matrix in presence of nano-SiO2 particles.
{"title":"An Investigation on the Effects of Adding Nano-Sio2 Particles and Silica Fume with Different Specific Surface Areas on the Physical and Mechanical Parameters of Soil-Cement Materials","authors":"M. Tajdini, M. Bargi, Omid Rasouli Ghahroudi","doi":"10.22059/CEIJ.2021.291231.1619","DOIUrl":"https://doi.org/10.22059/CEIJ.2021.291231.1619","url":null,"abstract":"Soil cement is a mixture of Portland cement, soil and water, in which hydration of cement and compaction causes the materials’ constituents to bond together makes a dense and durable composition with low permeability and abrasion resistant. Since most of the recent researches are focused on the addition of nano-SiO2 on concrete, in this paper it has been attempted to use nano-SiO2 particles in soil-cement and observe the effects. Due to the fact that in concrete there are no particles passing sieve 200 and this restriction does not apply to soil-cements, some tests were carried out on the nano-SiO2 + soil-cement matrix because of the meaningful difference between concrete and soil-cement. The test procedure consists of moisture-dry density, unconfined compressive test and hydraulic conductivity. In these tests, silica fume (with specific surface area of 21 m2/g), nano-SiO2 (with specific surface area of 200 and 380 m2/g) were added to soil-cement. The results show that adding certain amounts of nano-SiO2 particles to the soil-cement matrix can improve the compressive strength and reduce permeability and speed hydration reactions in the matrix in presence of nano-SiO2 particles.","PeriodicalId":43959,"journal":{"name":"Civil Engineering Infrastructures Journal-CEIJ","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49595082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-28DOI: 10.22059/CEIJ.2020.288257.1611
Atefeh Gholamzadeh Chitgar, J. Berenjian
In the present study, Radial Basis Function (RBF) neural networks were applied to forecast the compressive strength and elastic modulus of Self-Compacting Concrete (SCC). To construct the models, different experimental specimens of diverse kinds of SCC were gathered from the literature. The data used in the networks were classified into two different sets of input parameters. The results revealed that the proposed RBF models can accurately forecast the properties of SCCs with low test error. Furthermore, a comparison between models with two different sets of inputs proves that the selected parameters as input variables, straightly impress the precision of the networks, in the prediction of the intended outputs.
{"title":"Performance Evaluation of RBF Networks with Various Variables to Forecast the Properties of SCCs","authors":"Atefeh Gholamzadeh Chitgar, J. Berenjian","doi":"10.22059/CEIJ.2020.288257.1611","DOIUrl":"https://doi.org/10.22059/CEIJ.2020.288257.1611","url":null,"abstract":"In the present study, Radial Basis Function (RBF) neural networks were applied to forecast the compressive strength and elastic modulus of Self-Compacting Concrete (SCC). To construct the models, different experimental specimens of diverse kinds of SCC were gathered from the literature. The data used in the networks were classified into two different sets of input parameters. The results revealed that the proposed RBF models can accurately forecast the properties of SCCs with low test error. Furthermore, a comparison between models with two different sets of inputs proves that the selected parameters as input variables, straightly impress the precision of the networks, in the prediction of the intended outputs.","PeriodicalId":43959,"journal":{"name":"Civil Engineering Infrastructures Journal-CEIJ","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48624538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-28DOI: 10.22059/CEIJ.2020.291570.1624
G. Silpa, I. Y. Sreevalli
The reinforced concrete flat slab structures are highly susceptible to punching shear failure. This occurs due to the transferring of shear force and due to the bending moment between the slab and the column. The initial local failure and the following redistribution of load can lead to punching failure of the slab in the adjacent column locations. This issue can collapse an entire building or a huge portion of a structure. Hence, an alternate load path method is necessary for preventing the catastrophic failure of the buildings. Compared to the moment frame buildings, flat slab buildings are more prone to the progressive collapse. Thus, the designing of flat plate structures demands more attention and study. Due to higher construction costs and limitations in the test set up, the researchers have adopted scale down structures for the experimental studies. The progressive collapse behavior of the prototype structures is usually analyzed using both analytical and numerical simulations. This paper discusses the existing researchers on the analytical study, experimental study, and numerical simulations of flat slab structures along with various load resisting mechanisms to mitigate progressive collapse. Further, various strengthening techniques available in the literature for the flat slab structures have been discussed. A parametric study and comparison of different strengthening techniques are also performed in this work.
{"title":"A Review on Progressive Collapse of Reinforced Concrete Flat Slab Structures","authors":"G. Silpa, I. Y. Sreevalli","doi":"10.22059/CEIJ.2020.291570.1624","DOIUrl":"https://doi.org/10.22059/CEIJ.2020.291570.1624","url":null,"abstract":"The reinforced concrete flat slab structures are highly susceptible to punching shear failure. This occurs due to the transferring of shear force and due to the bending moment between the slab and the column. The initial local failure and the following redistribution of load can lead to punching failure of the slab in the adjacent column locations. This issue can collapse an entire building or a huge portion of a structure. Hence, an alternate load path method is necessary for preventing the catastrophic failure of the buildings. Compared to the moment frame buildings, flat slab buildings are more prone to the progressive collapse. Thus, the designing of flat plate structures demands more attention and study. Due to higher construction costs and limitations in the test set up, the researchers have adopted scale down structures for the experimental studies. The progressive collapse behavior of the prototype structures is usually analyzed using both analytical and numerical simulations. This paper discusses the existing researchers on the analytical study, experimental study, and numerical simulations of flat slab structures along with various load resisting mechanisms to mitigate progressive collapse. Further, various strengthening techniques available in the literature for the flat slab structures have been discussed. A parametric study and comparison of different strengthening techniques are also performed in this work.","PeriodicalId":43959,"journal":{"name":"Civil Engineering Infrastructures Journal-CEIJ","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44349599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-28DOI: 10.22059/CEIJ.2020.292639.1628
M. Moradi, H. Tavakoli, G. Abdollahzadeh
Two fire accidents took place in the Plasco Tower in Iran and Grenfell Tower of London in 2017. Although both of them have led to human tragedies, post-earthquake fire can cause more irreparable damages and catastrophes in larger extents. Engineering structures are subjected to different loads during their lifetime, which may cause damage or secondary loading effects. Evaluation of durability and stability of fired structures and the effects of seismic loading are considered to be significant parameters in fire engineering. The aim of this study is to evaluate and compare durability of reinforced concrete and steel frames during fire loading and post-earthquake fires. In this study, two 7-story steel and reinforced concrete frames are exposed to the fire load. At first, steel and concrete sections are put under various thermal loads in order to compare the method of their heat transfer. Then, the effects of crack on heat transfer of concrete sections are studied. Afterwards, the selected frames are exposed to the fire and post-earthquake fires. The results indicated that cracking and strength reduction due to seismic loading can decrease the durability of reinforced concrete frame in post-earthquake fire scenarios. However, the durability of steel frames has no significant relationship with the seismic loading and their durability are almost the same in the fire and post-earthquake fire scenarios.
{"title":"Comparison of Steel and Reinforced Concrete Frames’ Durability under Fire and Post-Earthquake Fire Scenario","authors":"M. Moradi, H. Tavakoli, G. Abdollahzadeh","doi":"10.22059/CEIJ.2020.292639.1628","DOIUrl":"https://doi.org/10.22059/CEIJ.2020.292639.1628","url":null,"abstract":"Two fire accidents took place in the Plasco Tower in Iran and Grenfell Tower of London in 2017. Although both of them have led to human tragedies, post-earthquake fire can cause more irreparable damages and catastrophes in larger extents. Engineering structures are subjected to different loads during their lifetime, which may cause damage or secondary loading effects. Evaluation of durability and stability of fired structures and the effects of seismic loading are considered to be significant parameters in fire engineering. The aim of this study is to evaluate and compare durability of reinforced concrete and steel frames during fire loading and post-earthquake fires. In this study, two 7-story steel and reinforced concrete frames are exposed to the fire load. At first, steel and concrete sections are put under various thermal loads in order to compare the method of their heat transfer. Then, the effects of crack on heat transfer of concrete sections are studied. Afterwards, the selected frames are exposed to the fire and post-earthquake fires. The results indicated that cracking and strength reduction due to seismic loading can decrease the durability of reinforced concrete frame in post-earthquake fire scenarios. However, the durability of steel frames has no significant relationship with the seismic loading and their durability are almost the same in the fire and post-earthquake fire scenarios.","PeriodicalId":43959,"journal":{"name":"Civil Engineering Infrastructures Journal-CEIJ","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47171013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-28DOI: 10.22059/CEIJ.2020.287489.1607
Mohammad Mahdi Hajitaheriha, Faezeh Jafari, M. Hassanlourad, Amin Hasani Motlagh
In this study, the impact of Negative Skin Friction (NSF) on composite piles concerning different variables such as different pile sections, the amount of concrete and steel consumption, and various interaction coefficients of the pile-soil system in both solid and hollow conditions are evaluated using numerical methods. Besides, the effect of the variables considered on the negative skin friction and pile’s settlement is investigated. Numerical analyses were performed using ABAQUS and MATLAB. The results showed that the amount of frictional stress on the pile decreases if the hollow sections are used. However, the hallow pile experiences more settlements than other piles’ models. On the other hand, if the amount of consumed steel in a pile is reduced, the amount of negative skin friction induced in a pile decreases, while the pile settlement increases. After examining the Finite Element of concrete piles in fine-grained soils, the safety surface of the suggested numerical relationship is considered in the phenomenon of negative friction on the pile. For this purpose, considering the uncertainty parameters such as mean, variance and probability function for overcharge, soil parameters, dimensions and different types of the single pile, the amount of settlement, the stress created on the pile, the position of neutral plane on the pile and drag load were calculated using the proposed relationship. Finally, the safety surface of proposed relationships or comparisons of a finite element results in a close approximation to the real models is computed.
{"title":"Investigating the Reliability of Negative Skin Friction on Composite Piles","authors":"Mohammad Mahdi Hajitaheriha, Faezeh Jafari, M. Hassanlourad, Amin Hasani Motlagh","doi":"10.22059/CEIJ.2020.287489.1607","DOIUrl":"https://doi.org/10.22059/CEIJ.2020.287489.1607","url":null,"abstract":"In this study, the impact of Negative Skin Friction (NSF) on composite piles concerning different variables such as different pile sections, the amount of concrete and steel consumption, and various interaction coefficients of the pile-soil system in both solid and hollow conditions are evaluated using numerical methods. Besides, the effect of the variables considered on the negative skin friction and pile’s settlement is investigated. Numerical analyses were performed using ABAQUS and MATLAB. The results showed that the amount of frictional stress on the pile decreases if the hollow sections are used. However, the hallow pile experiences more settlements than other piles’ models. On the other hand, if the amount of consumed steel in a pile is reduced, the amount of negative skin friction induced in a pile decreases, while the pile settlement increases. After examining the Finite Element of concrete piles in fine-grained soils, the safety surface of the suggested numerical relationship is considered in the phenomenon of negative friction on the pile. For this purpose, considering the uncertainty parameters such as mean, variance and probability function for overcharge, soil parameters, dimensions and different types of the single pile, the amount of settlement, the stress created on the pile, the position of neutral plane on the pile and drag load were calculated using the proposed relationship. Finally, the safety surface of proposed relationships or comparisons of a finite element results in a close approximation to the real models is computed.","PeriodicalId":43959,"journal":{"name":"Civil Engineering Infrastructures Journal-CEIJ","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48226517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-28DOI: 10.22059/CEIJ.2020.287507.1610
H. Motamedi, H. Amiri, H. Fazaeli, M. Aliha
The use of Edge Notched Disc Beam (ENDB) sample has been proposed as a suitable geometry in performing fracture tests in different loading modes. The most important features of the ENDB samples include easy making, quick and easy sampling, simple testing, and the ability to examine a wide range of pure and combined loading modes. Using a wide range of fracture tests, a statistical model is proposed to predict the stress intensity factors of asphalt mixtures in terms of the pure torsion mode (mode III) loading in this study. To this end, the experiments were carried out at different temperature conditions (-5, -15 and -25 °C), different loading conditions (0.5, 1 and 5 mm/min), and on control and modified asphalt mixtures with different percentages of polyolefin-aramid fibers. The results showed that, with increasing the fiber content and loading rate, the fracture strength increased with average 25%, while an increase in fracture toughness due to lower temperature had an effect of less than 5%. Using the Response Surface Method (RSM), the prediction model of stress intensity coefficients of asphalt mixtures was presented in the pure torsion mode. The results of the proposed models had a good correlation with the results of the conducted fracture tests.
{"title":"Providing a Prediction Model for Stress Intensity Factor of Fiber- Reinforced Asphalt Mixtures under Pure Mode III Loading Using the Edge Notched Disc Beam (ENDB)","authors":"H. Motamedi, H. Amiri, H. Fazaeli, M. Aliha","doi":"10.22059/CEIJ.2020.287507.1610","DOIUrl":"https://doi.org/10.22059/CEIJ.2020.287507.1610","url":null,"abstract":"The use of Edge Notched Disc Beam (ENDB) sample has been proposed as a suitable geometry in performing fracture tests in different loading modes. The most important features of the ENDB samples include easy making, quick and easy sampling, simple testing, and the ability to examine a wide range of pure and combined loading modes. Using a wide range of fracture tests, a statistical model is proposed to predict the stress intensity factors of asphalt mixtures in terms of the pure torsion mode (mode III) loading in this study. To this end, the experiments were carried out at different temperature conditions (-5, -15 and -25 °C), different loading conditions (0.5, 1 and 5 mm/min), and on control and modified asphalt mixtures with different percentages of polyolefin-aramid fibers. The results showed that, with increasing the fiber content and loading rate, the fracture strength increased with average 25%, while an increase in fracture toughness due to lower temperature had an effect of less than 5%. Using the Response Surface Method (RSM), the prediction model of stress intensity coefficients of asphalt mixtures was presented in the pure torsion mode. The results of the proposed models had a good correlation with the results of the conducted fracture tests.","PeriodicalId":43959,"journal":{"name":"Civil Engineering Infrastructures Journal-CEIJ","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48881441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-28DOI: 10.22059/CEIJ.2020.288767.1612
M. Mortazavi, M. Ghassemieh, A. Valadbeigi
Unexpected loading, induced by severe earthquake or blast, could cause local damage to a structure. In this case, the structure has the potential of progressive collapse phenomenon. Hence, further consideration is required to mitigate the consequences of such loading. This study is aimed to evaluate the progressive collapse capacity of steel moment frames with different heights under column removal conditions. Seven and twelve story buildings modeled in different conditions in order to view effects of various parameters like the out of plane frames, column removal location, and the height of buildings in the results. One of the middle column and/or the corner columns is removed in order to evaluate the effect of column removal location in response of structures. The General Services Administration and the Department of Defense guidelines are considered for defining load combination for the analysis of the collapse. Nonlinear dynamic analysis is conducted in order to obtain the ductility demand of structures when the out of plane effect is considered. The structures have welded cover plate connections, designed for high-seismic zone area. For evaluating the response of the structures, for each connection at the point of column removal, maximum vertical displacement is measured. For Finite Element analysis, a sub-assemblage of structures is modeled using ABAQUS software and the ability of beams deformation and its out of plane effect is measured.
{"title":"The Effect of Out of Plane Perpendicular Beams on the Ductility Demand of Steel Moment Framed Structures during Progressive Collapse","authors":"M. Mortazavi, M. Ghassemieh, A. Valadbeigi","doi":"10.22059/CEIJ.2020.288767.1612","DOIUrl":"https://doi.org/10.22059/CEIJ.2020.288767.1612","url":null,"abstract":"Unexpected loading, induced by severe earthquake or blast, could cause local damage to a structure. In this case, the structure has the potential of progressive collapse phenomenon. Hence, further consideration is required to mitigate the consequences of such loading. This study is aimed to evaluate the progressive collapse capacity of steel moment frames with different heights under column removal conditions. Seven and twelve story buildings modeled in different conditions in order to view effects of various parameters like the out of plane frames, column removal location, and the height of buildings in the results. One of the middle column and/or the corner columns is removed in order to evaluate the effect of column removal location in response of structures. The General Services Administration and the Department of Defense guidelines are considered for defining load combination for the analysis of the collapse. Nonlinear dynamic analysis is conducted in order to obtain the ductility demand of structures when the out of plane effect is considered. The structures have welded cover plate connections, designed for high-seismic zone area. For evaluating the response of the structures, for each connection at the point of column removal, maximum vertical displacement is measured. For Finite Element analysis, a sub-assemblage of structures is modeled using ABAQUS software and the ability of beams deformation and its out of plane effect is measured.","PeriodicalId":43959,"journal":{"name":"Civil Engineering Infrastructures Journal-CEIJ","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47950676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-28DOI: 10.22059/CEIJ.2020.292296.1627
Ibtesam Abudallah Habib, W. Mohtar, K. Shahot, A. El-shafie, Teh Sabariah Abd Manan
The inherent scour process around the bridge piers needs to be considered and crucial to ensure a sustainable and economical bridge design. The performance of any scour protection/controlling devices around bridge piers is determined on how each device counters or minimize the scouring process. Besides the usually adopted bed armouring, abundant studies have been conducted to evaluate the efficiency of flow-altering countermeasures in reducing local scour depth. The flow changes due to the rigid pier are modified in a way to reduce the impinging effect on the bed. This paper discusses on the performance and feasibility of self-protected piers, defined as a pier without any additional structure built either next to or at a distance away from the pier. We paid attention to the efficiency of the proposed countermeasures in terms of possible maximum scour reduction and provide the best configuration of each self-protection pier. This review consists of analysis on the openings on pier including internal tubing, slot and pier groups, and modified pier shapes as the flow-altering, self-protected countermeasure alternatives.
{"title":"Bridge Failure Prevention: An Overview of Self-Protected Pier as Flow Altering Countermeasures for Scour Protection","authors":"Ibtesam Abudallah Habib, W. Mohtar, K. Shahot, A. El-shafie, Teh Sabariah Abd Manan","doi":"10.22059/CEIJ.2020.292296.1627","DOIUrl":"https://doi.org/10.22059/CEIJ.2020.292296.1627","url":null,"abstract":"The inherent scour process around the bridge piers needs to be considered and crucial to ensure a sustainable and economical bridge design. The performance of any scour protection/controlling devices around bridge piers is determined on how each device counters or minimize the scouring process. Besides the usually adopted bed armouring, abundant studies have been conducted to evaluate the efficiency of flow-altering countermeasures in reducing local scour depth. The flow changes due to the rigid pier are modified in a way to reduce the impinging effect on the bed. This paper discusses on the performance and feasibility of self-protected piers, defined as a pier without any additional structure built either next to or at a distance away from the pier. We paid attention to the efficiency of the proposed countermeasures in terms of possible maximum scour reduction and provide the best configuration of each self-protection pier. This review consists of analysis on the openings on pier including internal tubing, slot and pier groups, and modified pier shapes as the flow-altering, self-protected countermeasure alternatives.","PeriodicalId":43959,"journal":{"name":"Civil Engineering Infrastructures Journal-CEIJ","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43700801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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