{"title":"Issue Information","authors":"","doi":"10.1002/tal.1953","DOIUrl":"https://doi.org/10.1002/tal.1953","url":null,"abstract":"No abstract is available for this article.","PeriodicalId":49470,"journal":{"name":"Structural Design of Tall and Special Buildings","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45162686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper investigated the fire behavior of steel‐concrete composite beams (SCB) and partially encased steel‐concrete composite beams (PEB) through numerical analysis. The numerical models established by the software ABAQUS were verified against experimental results. Parametric studies were performed to study the influences of load ratio, strength of concrete and steel, width of concrete slab, size of steel beam, fire protection layer, and degree of shear connection on the fire behavior of SCB and PEB. The analysis results show that the deformation stages of SCB and PEB under fire both go through four stages: elastic, elastic–plastic, plastic small deformation, and plastic large deformation. The web of SCB experiences a tension–compression–tension process under fire, and the bottom flange of PEB may even change from tension to compression at a lower load ratio. The failure mode of PEB, whether the concrete is crushed, depends on the load ratio. When SCB fails, the concrete is crushed and only the bottom flange of the steel beam yields. Under various parameters, the fire resistance of SCB is about 22 min, while the fire resistance of PEB is 82–93 min under a load of 0.4. When the load ratio increases from 0.2 to 0.6, the fire resistance of SCB decreases by 8 min, while that of PEB decreases by 110 min. To meet class I fire resistance rating under a normal service load ratio of 0.4, additional measures for PEB are still required, and at least 15 mm of fire protection layer is required for the steel beam of SCB. Finally, considering the temperature internal fore, a coefficient related to the fire time was introduced to modify the formula of ultimate flexural capacity of SCB and PEB, which showed good accuracy.
{"title":"Numerical analysis on mechanical behavior of steel‐concrete composite beams under fire","authors":"Wenjun Wang, Binhui Jiang, F. Ding, Liping Wang","doi":"10.1002/tal.2012","DOIUrl":"https://doi.org/10.1002/tal.2012","url":null,"abstract":"This paper investigated the fire behavior of steel‐concrete composite beams (SCB) and partially encased steel‐concrete composite beams (PEB) through numerical analysis. The numerical models established by the software ABAQUS were verified against experimental results. Parametric studies were performed to study the influences of load ratio, strength of concrete and steel, width of concrete slab, size of steel beam, fire protection layer, and degree of shear connection on the fire behavior of SCB and PEB. The analysis results show that the deformation stages of SCB and PEB under fire both go through four stages: elastic, elastic–plastic, plastic small deformation, and plastic large deformation. The web of SCB experiences a tension–compression–tension process under fire, and the bottom flange of PEB may even change from tension to compression at a lower load ratio. The failure mode of PEB, whether the concrete is crushed, depends on the load ratio. When SCB fails, the concrete is crushed and only the bottom flange of the steel beam yields. Under various parameters, the fire resistance of SCB is about 22 min, while the fire resistance of PEB is 82–93 min under a load of 0.4. When the load ratio increases from 0.2 to 0.6, the fire resistance of SCB decreases by 8 min, while that of PEB decreases by 110 min. To meet class I fire resistance rating under a normal service load ratio of 0.4, additional measures for PEB are still required, and at least 15 mm of fire protection layer is required for the steel beam of SCB. Finally, considering the temperature internal fore, a coefficient related to the fire time was introduced to modify the formula of ultimate flexural capacity of SCB and PEB, which showed good accuracy.","PeriodicalId":49470,"journal":{"name":"Structural Design of Tall and Special Buildings","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44413893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The life‐cycle cost‐oriented design philosophy is a promising tool for building resilient cities as it helps in gaining insights into the impact of hazard‐induced damage and repair of civil and infrastructure systems. In this study, a socioeconomic parameter‐independent practical formulation was introduced for life‐cycle cost analysis by combining the economic loss rate associated with different damage limit states and cloud analysis‐based probabilistic seismic demand model. A framework for life‐cycle cost analysis‐based seismic design optimization was proposed using an emerging nature‐inspired algorithm, namely, the multiobjective cuckoo search. By considering an eight‐story prototype composite frame, the framework was used to determine the trade‐off design alternatives between competing optimization objectives. Conventional and improved fiber models were developed to comparatively evaluate the influence of the slab spatial composite effect on Pareto optimal designs. The key drivers of change in three cost indicators were identified using generalized linear models. The result indicates that the overstrength factor is the critical design parameter affecting the initial construction, seismic damage, and life‐cycle costs, with statistical significance at the 0.001 level.
{"title":"Life‐cycle cost‐oriented multiobjective optimization of composite frames considering the slab effect","authors":"Yongjun Lin, Xianzhao Zhang","doi":"10.1002/tal.2008","DOIUrl":"https://doi.org/10.1002/tal.2008","url":null,"abstract":"The life‐cycle cost‐oriented design philosophy is a promising tool for building resilient cities as it helps in gaining insights into the impact of hazard‐induced damage and repair of civil and infrastructure systems. In this study, a socioeconomic parameter‐independent practical formulation was introduced for life‐cycle cost analysis by combining the economic loss rate associated with different damage limit states and cloud analysis‐based probabilistic seismic demand model. A framework for life‐cycle cost analysis‐based seismic design optimization was proposed using an emerging nature‐inspired algorithm, namely, the multiobjective cuckoo search. By considering an eight‐story prototype composite frame, the framework was used to determine the trade‐off design alternatives between competing optimization objectives. Conventional and improved fiber models were developed to comparatively evaluate the influence of the slab spatial composite effect on Pareto optimal designs. The key drivers of change in three cost indicators were identified using generalized linear models. The result indicates that the overstrength factor is the critical design parameter affecting the initial construction, seismic damage, and life‐cycle costs, with statistical significance at the 0.001 level.","PeriodicalId":49470,"journal":{"name":"Structural Design of Tall and Special Buildings","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43484132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H‐shaped circular arc is a relatively novel type of open‐web steel arch, and currently, no reports have been published concerning its in‐plane stability. In this paper, the elastic and elastic–plastic in‐plane stability of the H‐shaped hollow circular arch is studied by theoretical deduction combined with numerical simulation. First, the overall shear rigidity of the H‐shaped circular arch is calculated, and the elastic buckling load formula of the arch is proposed and verified considering double shear deformation under full‐span radial and uniform loading. The overall elastic buckling load deduced in this paper is reasonable according to the finite element analysis. The results indicate that the influence of shear deformation on the overall elastic buckling load of the arch decreases with the increase of the span length. The arch‐bearing capacity is the largest when the rise‐span ratio is 0.25. Second, the restriction conditions necessary for avoiding local buckling of the chordal web before integral buckling of the H‐shaped steel hollow circular arch are analyzed. Finally, the elastic–plastic failure mechanism of the H‐shaped arch under full‐span radial and uniform loading is examined, and the formula for determining the ultimate bearing capacity that is achievable before failure under full‐span radial and uniform loading is proposed. ANSYS analysis shows that under the radial uniform loading, the chordal bars will yield near 1/4L and 3/4L, and ultimately, the structural failure of the lower chord occurs in the vicinity of 1/4L. The formulas presented in this paper agree well with the results obtained from the finite element analysis and can be used as a reference for engineering applications.
{"title":"In‐plane stability and shear deformation analysis of the H‐beam hollow arch","authors":"Xuejie Liu, Tong Xiao","doi":"10.1002/tal.2009","DOIUrl":"https://doi.org/10.1002/tal.2009","url":null,"abstract":"H‐shaped circular arc is a relatively novel type of open‐web steel arch, and currently, no reports have been published concerning its in‐plane stability. In this paper, the elastic and elastic–plastic in‐plane stability of the H‐shaped hollow circular arch is studied by theoretical deduction combined with numerical simulation. First, the overall shear rigidity of the H‐shaped circular arch is calculated, and the elastic buckling load formula of the arch is proposed and verified considering double shear deformation under full‐span radial and uniform loading. The overall elastic buckling load deduced in this paper is reasonable according to the finite element analysis. The results indicate that the influence of shear deformation on the overall elastic buckling load of the arch decreases with the increase of the span length. The arch‐bearing capacity is the largest when the rise‐span ratio is 0.25. Second, the restriction conditions necessary for avoiding local buckling of the chordal web before integral buckling of the H‐shaped steel hollow circular arch are analyzed. Finally, the elastic–plastic failure mechanism of the H‐shaped arch under full‐span radial and uniform loading is examined, and the formula for determining the ultimate bearing capacity that is achievable before failure under full‐span radial and uniform loading is proposed. ANSYS analysis shows that under the radial uniform loading, the chordal bars will yield near 1/4L and 3/4L, and ultimately, the structural failure of the lower chord occurs in the vicinity of 1/4L. The formulas presented in this paper agree well with the results obtained from the finite element analysis and can be used as a reference for engineering applications.","PeriodicalId":49470,"journal":{"name":"Structural Design of Tall and Special Buildings","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46619842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The wind direction in the atmospheric boundary layer (ABL) twists with height due to the Coriolis force; this phenomenon is called the Ekman spiral. However, this phenomenon is generally not considered in the present wind load estimation of super high‐rise buildings, which may lead to an incorrect estimation and affect the safety of structures. Therefore, this study considers and analyzes the influence of the Ekman spiral phenomenon in the wind direction reduction effect (WDRE) of the wind load of super high‐rise buildings. First, this paper proposes an empirical fitting equation for the twisted wind direction angle for a height of 100–800 m according to the classical Ekman spiral theory model (CE model). Subsequently, on the basis of twisted wind, this paper proposes a method for the correction of the wind direction reduction factors (WDRFs) of strong winds considering the influence of the Ekman spiral phenomenon in the design wind load estimation of super high‐rise buildings with heights of 400–800 m. A high‐frequency balance force measurement test of a square‐section super high‐rise building model was performed to analyze the influence of the Ekman spiral phenomenon on the WDRE of the aerodynamic force and wind‐induced response. Three Chinese cities (i.e., Beijing, Wuhan, and Kunming) are selected as case studies to illustrate the importance and necessity of the correction method. The results demonstrate that the proposed empirical fitting equation accurately determines the twisted wind direction angle at different latitudes and altitudes. Furthermore, estimating the design wind load while considering the WDRE and neglecting the influence of the Ekman spiral phenomenon may lead to a significant underestimation of the wind load of super high‐rise buildings, rendering the designed building structure more dangerous.
{"title":"Correction of direction reduction factors of extreme wind speed considering the Ekman spiral in the wind load estimation of super high‐rise buildings with heights of 400–800 m","authors":"Bin He, Y. Quan, Ming Gu, Jialu Chen","doi":"10.1002/tal.2004","DOIUrl":"https://doi.org/10.1002/tal.2004","url":null,"abstract":"The wind direction in the atmospheric boundary layer (ABL) twists with height due to the Coriolis force; this phenomenon is called the Ekman spiral. However, this phenomenon is generally not considered in the present wind load estimation of super high‐rise buildings, which may lead to an incorrect estimation and affect the safety of structures. Therefore, this study considers and analyzes the influence of the Ekman spiral phenomenon in the wind direction reduction effect (WDRE) of the wind load of super high‐rise buildings. First, this paper proposes an empirical fitting equation for the twisted wind direction angle for a height of 100–800 m according to the classical Ekman spiral theory model (CE model). Subsequently, on the basis of twisted wind, this paper proposes a method for the correction of the wind direction reduction factors (WDRFs) of strong winds considering the influence of the Ekman spiral phenomenon in the design wind load estimation of super high‐rise buildings with heights of 400–800 m. A high‐frequency balance force measurement test of a square‐section super high‐rise building model was performed to analyze the influence of the Ekman spiral phenomenon on the WDRE of the aerodynamic force and wind‐induced response. Three Chinese cities (i.e., Beijing, Wuhan, and Kunming) are selected as case studies to illustrate the importance and necessity of the correction method. The results demonstrate that the proposed empirical fitting equation accurately determines the twisted wind direction angle at different latitudes and altitudes. Furthermore, estimating the design wind load while considering the WDRE and neglecting the influence of the Ekman spiral phenomenon may lead to a significant underestimation of the wind load of super high‐rise buildings, rendering the designed building structure more dangerous.","PeriodicalId":49470,"journal":{"name":"Structural Design of Tall and Special Buildings","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45557231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Deng Yousheng, Zhang Keqin, Li Wenjie, Song Qian, Ma Erli
The coupling beam pile structure is a new type of foundation for high‐rise buildings that can be easily constructed. The vertical load‐bearing characteristics of the coupling beam pile structure are examined using indoor model tests and numerical calculations to optimize the beam structure's parameters. The validity of the finite element model is then confirmed, and the beam structure's width, length, and stiffness are changed to examine their effects on the load‐bearing capacity. The results show that the load–settlement curve of the structure varies slightly, with a 45.10% increase in load‐carrying capacity compared to a pile group foundation for the same load, and that the coupling beam can support heavier loads while also distributing the tension of the loads. The width and length of the coupling beam are proportional to the load‐carrying capacity of the structure. The width of the coupling beam should be kept at 3.5 times the pile diameter since any wider width results in the “wall group effect,” which reduces the foundation's ability to support the weight. The coupling beam's short length, which should be kept above 4.5 times the pile diameter, can aid in reducing the “pile group effect.” The coupling beam stiffness can be changed according to the scenario in practice; there is no upper limit. The coupling beam stiffness is 5 times the reference value when it has the strongest force transmission capacity but has essentially little impact on the structure's load‐carrying capacity.
{"title":"Optimization of beam parameters for coupling beam pile structure foundations under vertical loading","authors":"Deng Yousheng, Zhang Keqin, Li Wenjie, Song Qian, Ma Erli","doi":"10.1002/tal.2007","DOIUrl":"https://doi.org/10.1002/tal.2007","url":null,"abstract":"The coupling beam pile structure is a new type of foundation for high‐rise buildings that can be easily constructed. The vertical load‐bearing characteristics of the coupling beam pile structure are examined using indoor model tests and numerical calculations to optimize the beam structure's parameters. The validity of the finite element model is then confirmed, and the beam structure's width, length, and stiffness are changed to examine their effects on the load‐bearing capacity. The results show that the load–settlement curve of the structure varies slightly, with a 45.10% increase in load‐carrying capacity compared to a pile group foundation for the same load, and that the coupling beam can support heavier loads while also distributing the tension of the loads. The width and length of the coupling beam are proportional to the load‐carrying capacity of the structure. The width of the coupling beam should be kept at 3.5 times the pile diameter since any wider width results in the “wall group effect,” which reduces the foundation's ability to support the weight. The coupling beam's short length, which should be kept above 4.5 times the pile diameter, can aid in reducing the “pile group effect.” The coupling beam stiffness can be changed according to the scenario in practice; there is no upper limit. The coupling beam stiffness is 5 times the reference value when it has the strongest force transmission capacity but has essentially little impact on the structure's load‐carrying capacity.","PeriodicalId":49470,"journal":{"name":"Structural Design of Tall and Special Buildings","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46041402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Issue Information","authors":"","doi":"10.1002/tal.1952","DOIUrl":"https://doi.org/10.1002/tal.1952","url":null,"abstract":"No abstract is available for this article.","PeriodicalId":49470,"journal":{"name":"Structural Design of Tall and Special Buildings","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49299773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The aim of this paper is reducing the responses of structures under the mine blast‐induced ground motion by using semi‐active tools. In other words, the objective of this study is to provide a method to reduce the destructive effects of underground mine‐blast excitation. Investigating the behavior of structures under the mine blast excitation is essential because some buildings are subjected to the blast load of mines due to the rapid urbanization in different regions. Also, the importance of studying this excitation, based on the distinctive nature of mine blast‐induced underground motion, becomes more apparent. For proper investigation and comparison of responses, a seismic excitation is considered. To reduce the responses of two proposed shear structures, magnetorheological (MR) and orifice dampers are utilized. The optimum location for these dampers is investigated. To generate the optimal force each time step the clipped‐optimal algorithm is used based on the input force. The control force can be changed by adjusting the input voltage and magnetic field of dampers. In this research, structural responses based on optimal and maximum voltage are scrutinized. The results indicated that the proposed method is appropriate for reducing the responses of structures under the mine blast‐induced ground motion and seismic excitation.
{"title":"Mine blast‐induced ground motion response reduction using semi‐active devices","authors":"Amirreza Ghaffari, H. Ghaffarzadeh","doi":"10.1002/tal.2005","DOIUrl":"https://doi.org/10.1002/tal.2005","url":null,"abstract":"The aim of this paper is reducing the responses of structures under the mine blast‐induced ground motion by using semi‐active tools. In other words, the objective of this study is to provide a method to reduce the destructive effects of underground mine‐blast excitation. Investigating the behavior of structures under the mine blast excitation is essential because some buildings are subjected to the blast load of mines due to the rapid urbanization in different regions. Also, the importance of studying this excitation, based on the distinctive nature of mine blast‐induced underground motion, becomes more apparent. For proper investigation and comparison of responses, a seismic excitation is considered. To reduce the responses of two proposed shear structures, magnetorheological (MR) and orifice dampers are utilized. The optimum location for these dampers is investigated. To generate the optimal force each time step the clipped‐optimal algorithm is used based on the input force. The control force can be changed by adjusting the input voltage and magnetic field of dampers. In this research, structural responses based on optimal and maximum voltage are scrutinized. The results indicated that the proposed method is appropriate for reducing the responses of structures under the mine blast‐induced ground motion and seismic excitation.","PeriodicalId":49470,"journal":{"name":"Structural Design of Tall and Special Buildings","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44823613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The present study aims to identify damage in two‐dimensional (2‐D) moment frames using seismic responses by combining the random forest (RF) machine classifier and the enhanced gray wolf optimizer (EGWO) metaheuristic algorithm. First, a 2‐D moment frame for the dynamic analysis is simulated using the finite element method (FEM). Then, the placement of sensors is optimized using a proposed optimal sensor placement (POSP) method, which is a combination of the iterated improved reduced system (IIRS) and the binary differential evolution (BDE) optimization algorithm. The acceleration responses of the moment frame having damaged elements under 1995 Kobe earthquake are measured at the optimal sensor placement. Then, the natural frequencies and mode shapes of the structure are extracted using the auto‐regressive model with exogenous input method (ARX) as a system identification method. The natural frequencies are exploited to train an RF machine learning network that can find the damaged story of the moment frame. Then, EGWO is employed to accurately locate and quantify the damaged elements of the structure. The efficiency of the proposed method is assessed through considering a six‐story frame with 18 elements, a seven‐story frame with 49 elements, and the experimental data of an eight‐story frame for various conditions. The results show that the RF algorithm has an outstanding performance to correctly find a damaged story. Furthermore, the location and severity of damaged elements are precisely determined by EGWO algorithm. As a final outcome, it is demonstrated that the two‐step proposed method is very effective in seismically identifying damage to such structures.
{"title":"Seismic damage identification of moment frames based on random forest algorithm and enhanced gray wolf optimization","authors":"H. Nourizadeh, S. M. Seyedpoor","doi":"10.1002/tal.2006","DOIUrl":"https://doi.org/10.1002/tal.2006","url":null,"abstract":"The present study aims to identify damage in two‐dimensional (2‐D) moment frames using seismic responses by combining the random forest (RF) machine classifier and the enhanced gray wolf optimizer (EGWO) metaheuristic algorithm. First, a 2‐D moment frame for the dynamic analysis is simulated using the finite element method (FEM). Then, the placement of sensors is optimized using a proposed optimal sensor placement (POSP) method, which is a combination of the iterated improved reduced system (IIRS) and the binary differential evolution (BDE) optimization algorithm. The acceleration responses of the moment frame having damaged elements under 1995 Kobe earthquake are measured at the optimal sensor placement. Then, the natural frequencies and mode shapes of the structure are extracted using the auto‐regressive model with exogenous input method (ARX) as a system identification method. The natural frequencies are exploited to train an RF machine learning network that can find the damaged story of the moment frame. Then, EGWO is employed to accurately locate and quantify the damaged elements of the structure. The efficiency of the proposed method is assessed through considering a six‐story frame with 18 elements, a seven‐story frame with 49 elements, and the experimental data of an eight‐story frame for various conditions. The results show that the RF algorithm has an outstanding performance to correctly find a damaged story. Furthermore, the location and severity of damaged elements are precisely determined by EGWO algorithm. As a final outcome, it is demonstrated that the two‐step proposed method is very effective in seismically identifying damage to such structures.","PeriodicalId":49470,"journal":{"name":"Structural Design of Tall and Special Buildings","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41832153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents a new approach to the project of steel buildings, mainly focused on the architectural, structural, and seismic design of stairs. The objective is to design a structural stair system capable of controlling seismic damage and contributing to the bracing system of the building. The article begins with a review of the seismic standard (ATC, FEMA, and EC8) on which the current design criteria for new buildings with stairs are based. The research is based on two spatial building models (A–B) with the same bracing elements but placed differently. Reference Model A follows classical design approaches. It means, stairs are considered nonstructural elements that do not influence the seismic behavior of the building. This structure corresponds to typical braced frames (IV‐CBF and EBF) according to EC8. Model B includes a stair system designed to help control the effects of inter‐story drifts and inertia forces. In this case, the same bracing elements of Model A were integrated into the stair structure of Model B. A comparative seismic behavior analysis of typically braced frames (A) versus specially braced stairs (B) is presented. The research was based on the static nonlinear (pushover) analysis and the capacity spectrum method (ATC‐40) according to the seismic performance levels (FEMA) and damage limitation (EC8). Finally, the braced stairs was verified via nonlinear time‐history analysis in order to better capture the structural safety of the evacuation routes and their influence on the behavior of the building. This deterministic analysis of the braced stairs verified satisfactory results compared to reference bracing systems.
{"title":"Special braced stairs versus typical braced frames. New architectural‐structural‐seismic approach to stair design","authors":"Carlos Montalbán Turon, Yeudy F. Vargas Alzate","doi":"10.1002/tal.1997","DOIUrl":"https://doi.org/10.1002/tal.1997","url":null,"abstract":"This paper presents a new approach to the project of steel buildings, mainly focused on the architectural, structural, and seismic design of stairs. The objective is to design a structural stair system capable of controlling seismic damage and contributing to the bracing system of the building. The article begins with a review of the seismic standard (ATC, FEMA, and EC8) on which the current design criteria for new buildings with stairs are based. The research is based on two spatial building models (A–B) with the same bracing elements but placed differently. Reference Model A follows classical design approaches. It means, stairs are considered nonstructural elements that do not influence the seismic behavior of the building. This structure corresponds to typical braced frames (IV‐CBF and EBF) according to EC8. Model B includes a stair system designed to help control the effects of inter‐story drifts and inertia forces. In this case, the same bracing elements of Model A were integrated into the stair structure of Model B. A comparative seismic behavior analysis of typically braced frames (A) versus specially braced stairs (B) is presented. The research was based on the static nonlinear (pushover) analysis and the capacity spectrum method (ATC‐40) according to the seismic performance levels (FEMA) and damage limitation (EC8). Finally, the braced stairs was verified via nonlinear time‐history analysis in order to better capture the structural safety of the evacuation routes and their influence on the behavior of the building. This deterministic analysis of the braced stairs verified satisfactory results compared to reference bracing systems.","PeriodicalId":49470,"journal":{"name":"Structural Design of Tall and Special Buildings","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43765900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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