Pub Date : 2025-06-01DOI: 10.1016/j.rcns.2025.06.002
Ashraf Labib
This paper aims to provide a window opportunity to share a reflection and learning from different countries and from other disciplines with the focus on resilience. There is also an attempt to theorize the concept of learning from spurious success and failure in the context of COVID-19. The main emphasis is to provide understanding of the causal factors and the identification of improved measures and modelling approaches to prevent and mitigate against future pandemics. Proposed decision tools of resilience and bowtie modelling as enablers for decision makers to prevent hazards and protect against their consequences.
{"title":"Spurious learning and bouncing back: Resilience and simulation modelling applied to the COVID-19 pandemic","authors":"Ashraf Labib","doi":"10.1016/j.rcns.2025.06.002","DOIUrl":"10.1016/j.rcns.2025.06.002","url":null,"abstract":"<div><div>This paper aims to provide a window opportunity to share a reflection and learning from different countries and from other disciplines with the focus on resilience. There is also an attempt to theorize the concept of learning from spurious success and failure in the context of COVID-19. The main emphasis is to provide understanding of the causal factors and the identification of improved measures and modelling approaches to prevent and mitigate against future pandemics. Proposed decision tools of resilience and bowtie modelling as enablers for decision makers to prevent hazards and protect against their consequences.</div></div>","PeriodicalId":101077,"journal":{"name":"Resilient Cities and Structures","volume":"4 2","pages":"Pages 84-91"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144270507","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 : 2025-06-01DOI: 10.1016/j.rcns.2025.05.001
Tadesse G. Wakjira , M. Shahria Alam
Efficient seismic vulnerability and resilience assessment is essential for ultra-high-performance concrete (UHPC) bridges, given their distinctive mechanical and structural properties. However, existing single-parameter-based probabilistic seismic demand (PSD) models overlook critical bridge‐specific characteristics and uncertainties. Besides, studies on seismic vulnerability and resilience assessment of UHPC bridges are scarce. Thus, this study proposes a hybrid machine learning (ML)-enabled multivariate bridge-specific seismic vulnerability and resilience assessment framework for UHPC bridges. Key design parameters and associated uncertainties are identified, and a Latin Hypercube Sampling (LHS) technique is employed to establish a representative UHPC bridge database, which is used to develop a hybrid ML model-based multivariate PSD model. A comparative analysis with the conventional PSD model, as well as widely used ML algorithms, demonstrated that the proposed PSD model achieves the highest predictive performance, characterized by the highest coefficient of determination and lowest prediction errors. Additionally, SHapley Additive exPlanation (SHAP) analysis is used to investigate the effect of different parameters on the PSD of UHPC bridges. The results of SHAP show the peak ground acceleration (PGA) as the most important factor, followed by bridge span and column diameter. The hybrid ML-enabled multi-variate bridge-specific fragility analysis results are used to investigate the functionality recovery and resilience of the bridge, which demonstrate the reduction in the residual functionality and overall bridge resilience with the increase in the ground motion intensity.
{"title":"Hybrid machine learning-enabled multivariate bridge-specific seismic vulnerability and resilience assessment of UHPC bridges","authors":"Tadesse G. Wakjira , M. Shahria Alam","doi":"10.1016/j.rcns.2025.05.001","DOIUrl":"10.1016/j.rcns.2025.05.001","url":null,"abstract":"<div><div>Efficient seismic vulnerability and resilience assessment is essential for ultra-high-performance concrete (UHPC) bridges, given their distinctive mechanical and structural properties. However, existing single-parameter-based probabilistic seismic demand (PSD) models overlook critical bridge‐specific characteristics and uncertainties. Besides, studies on seismic vulnerability and resilience assessment of UHPC bridges are scarce. Thus, this study proposes a hybrid machine learning (ML)-enabled multivariate bridge-specific seismic vulnerability and resilience assessment framework for UHPC bridges. Key design parameters and associated uncertainties are identified, and a Latin Hypercube Sampling (LHS) technique is employed to establish a representative UHPC bridge database, which is used to develop a hybrid ML model-based multivariate PSD model. A comparative analysis with the conventional PSD model, as well as widely used ML algorithms, demonstrated that the proposed PSD model achieves the highest predictive performance, characterized by the highest coefficient of determination and lowest prediction errors. Additionally, SHapley Additive exPlanation (SHAP) analysis is used to investigate the effect of different parameters on the PSD of UHPC bridges. The results of SHAP show the peak ground acceleration (PGA) as the most important factor, followed by bridge span and column diameter. The hybrid ML-enabled multi-variate bridge-specific fragility analysis results are used to investigate the functionality recovery and resilience of the bridge, which demonstrate the reduction in the residual functionality and overall bridge resilience with the increase in the ground motion intensity.</div></div>","PeriodicalId":101077,"journal":{"name":"Resilient Cities and Structures","volume":"4 2","pages":"Pages 92-102"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144271024","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 : 2025-06-01DOI: 10.1016/j.rcns.2025.05.002
Xu Han , Maria Koliou
There has been a large increase in the number of days per year with numerous EF1-EF5 tornadoes. Given the significant damage incurred by tornadoes upon communities, community resilience analyses for tornado-stricken communities have been gaining momentum. As the community resilience analysis aims to guide how to lay out effective hazard mitigation strategies to decrease damage and improve recovery, a comprehensive and accurate approach is necessary. Agent-based modeling, an analysis approach in which different types of agents are created with their properties and behavior clearly defined to simulate the processes of those agents in an external environment, is the most comprehensive and accurate approach so far to conducting community resilience simulations and investigating the decision-making for mitigation and recovery under natural hazards. In this paper, agent-based models (ABMs) are created to simulate the recovery process of a virtual testbed based on the real-world community in Joplin City, MO. The tornado path associated with the real-world tornado event that occurred in May 2011 is adopted in the tornado hazard modeling for the Joplin testbed. In addition, agent-based models are created for another virtual community in the Midwest United States named Centerville using an assumed tornado scenario of the same EF-scale as that in Joplin. The effects of hazard mitigation strategies on the two communities are also explored. A comparison between the analysis results of these two testbeds can indicate the influence of the characteristics of a tornado-prone community on the resilience of the community as well as on the effects of hazard mitigation strategies. It is observed that a community's level of development significantly impacts the tornado resilience. In addition, the effects of a specific type of hazard mitigation strategy on the recovery process are contingent upon testbed characteristics.
{"title":"Influence of testbed characteristics on community resilience using agent-based modeling","authors":"Xu Han , Maria Koliou","doi":"10.1016/j.rcns.2025.05.002","DOIUrl":"10.1016/j.rcns.2025.05.002","url":null,"abstract":"<div><div>There has been a large increase in the number of days per year with numerous EF1-EF5 tornadoes. Given the significant damage incurred by tornadoes upon communities, community resilience analyses for tornado-stricken communities have been gaining momentum. As the community resilience analysis aims to guide how to lay out effective hazard mitigation strategies to decrease damage and improve recovery, a comprehensive and accurate approach is necessary. Agent-based modeling, an analysis approach in which different types of agents are created with their properties and behavior clearly defined to simulate the processes of those agents in an external environment, is the most comprehensive and accurate approach so far to conducting community resilience simulations and investigating the decision-making for mitigation and recovery under natural hazards. In this paper, agent-based models (ABMs) are created to simulate the recovery process of a virtual testbed based on the real-world community in Joplin City, MO. The tornado path associated with the real-world tornado event that occurred in May 2011 is adopted in the tornado hazard modeling for the Joplin testbed. In addition, agent-based models are created for another virtual community in the Midwest United States named Centerville using an assumed tornado scenario of the same EF-scale as that in Joplin. The effects of hazard mitigation strategies on the two communities are also explored. A comparison between the analysis results of these two testbeds can indicate the influence of the characteristics of a tornado-prone community on the resilience of the community as well as on the effects of hazard mitigation strategies. It is observed that a community's level of development significantly impacts the tornado resilience. In addition, the effects of a specific type of hazard mitigation strategy on the recovery process are contingent upon testbed characteristics.</div></div>","PeriodicalId":101077,"journal":{"name":"Resilient Cities and Structures","volume":"4 2","pages":"Pages 69-83"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263979","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 : 2025-06-01DOI: 10.1016/j.rcns.2025.06.001
Ashkan Hashemi, Rajnil Lal
The application of mass timber elements in different structures has gained publicity over the last few years, primarily due to climate change adaptation policies and net zero carbon targets. Timber is a renewable construction material that can outperform other building materials regarding environmental impact. However, when used in seismically active regions, its application has been limited due to the uncertainties on their seismic behaviour in respect with different design standards and limited ductility in conventional connections. Conventional timber connections typically suffer from stiffness and strength degradation under cyclic loads. Their repairability is also low due to permanent damage in the fasteners and the associated crushing in the wood fibres. The use of friction connections can be an efficient way to mitigate these issues. They offer many advantages as they are economical and yet provide a high level of reliable and continuous energy dissipation. In recent years, a new generation of friction connections has been developed that can provide self-centring behaviour (i.e., the ability of the structure to return to its original position at the end of an earthquake). However, how these connections perform compared to a mass timber system with conventional timber connections is still unknown.
Several studies in the literature have suggested that these connections can enhance the performance of mass timber structures. However, the seismic performance of such systems specifically in terms of base shear, response drifts and response accelerations—has not been thoroughly investigated. This paper examines various design aspects of conventional friction connections and self-centring friction connections, providing insights into their differences concerning key seismic performance indicators. It compares the seismic performance of mass timber buildings equipped with both solutions, highlighting their advantages and limitations and drawing conclusions based on the results. The key findings are that friction connections can provides a superior seismic performance for timber structures. However, that may need to be combined with a parallel system avoid residual displacements.
{"title":"Seismic performance evaluation of mass timber buildings equipped with resilient and conventional friction devices","authors":"Ashkan Hashemi, Rajnil Lal","doi":"10.1016/j.rcns.2025.06.001","DOIUrl":"10.1016/j.rcns.2025.06.001","url":null,"abstract":"<div><div>The application of mass timber elements in different structures has gained publicity over the last few years, primarily due to climate change adaptation policies and net zero carbon targets. Timber is a renewable construction material that can outperform other building materials regarding environmental impact. However, when used in seismically active regions, its application has been limited due to the uncertainties on their seismic behaviour in respect with different design standards and limited ductility in conventional connections. Conventional timber connections typically suffer from stiffness and strength degradation under cyclic loads. Their repairability is also low due to permanent damage in the fasteners and the associated crushing in the wood fibres. The use of friction connections can be an efficient way to mitigate these issues. They offer many advantages as they are economical and yet provide a high level of reliable and continuous energy dissipation. In recent years, a new generation of friction connections has been developed that can provide self-centring behaviour (i.e., the ability of the structure to return to its original position at the end of an earthquake). However, how these connections perform compared to a mass timber system with conventional timber connections is still unknown.</div><div>Several studies in the literature have suggested that these connections can enhance the performance of mass timber structures. However, the seismic performance of such systems specifically in terms of base shear, response drifts and response accelerations—has not been thoroughly investigated. This paper examines various design aspects of conventional friction connections and self-centring friction connections, providing insights into their differences concerning key seismic performance indicators. It compares the seismic performance of mass timber buildings equipped with both solutions, highlighting their advantages and limitations and drawing conclusions based on the results. The key findings are that friction connections can provides a superior seismic performance for timber structures. However, that may need to be combined with a parallel system avoid residual displacements.</div></div>","PeriodicalId":101077,"journal":{"name":"Resilient Cities and Structures","volume":"4 2","pages":"Pages 103-115"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144308098","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 : 2025-04-22DOI: 10.1016/j.rcns.2025.02.006
Mohammad Kamali , Kasun Hewage , Anber Rana , Shahria Alam , Rehan Sadiq
Given the rapid growth of sustainable construction strategies globally and the importance of resiliency in civil infrastructure, it is crucial to adopt best practices. Modular construction is one such practice and is considered a better alternative to conventional construction in terms of resilience, construction times, resource efficiency, and sustainability. However, the continued expansion of modular construction relies on quantifying and evaluating its sustainability and the purported benefits. This paper develops and checks feasibility through an integrated multi-level decision support framework to empirically evaluate the sustainability performances of single-family residential modular homes. Criteria and indicator development and calculation, benchmark scale establishment, quantitative and qualitative data collection from literature and surveys, and multi-criteria decision analysis are unique aspects of this framework. The results of the two case studies located in the Okanagan region, Canada showed that modular homes perform at a higher level of sustainability than their conventional counterparts across multiple metrics and levels related to environmental and economic factors. The modular homes scored eco-efficiency values of 62.5 and 56.0, respectively and fell into higher performance range. The proposed framework offers flexibility in examining different dimensions of sustainability, providing valuable insights into the key parameters that need to be addressed to enhance overall sustainability. This research, which integrates life cycle thinking and decision-making, helps the construction industry and, municipalities, governments, and policymakers in making informed decisions on the selection of suitable construction methods in city developments and move towards a more resilient and sustainable sector.
{"title":"Advancing urban resilience with modular construction: An integrated sustainability assessment framework","authors":"Mohammad Kamali , Kasun Hewage , Anber Rana , Shahria Alam , Rehan Sadiq","doi":"10.1016/j.rcns.2025.02.006","DOIUrl":"10.1016/j.rcns.2025.02.006","url":null,"abstract":"<div><div>Given the rapid growth of sustainable construction strategies globally and the importance of resiliency in civil infrastructure, it is crucial to adopt best practices. Modular construction is one such practice and is considered a better alternative to conventional construction in terms of resilience, construction times, resource efficiency, and sustainability. However, the continued expansion of modular construction relies on quantifying and evaluating its sustainability and the purported benefits. This paper develops and checks feasibility through an integrated multi-level decision support framework to empirically evaluate the sustainability performances of single-family residential modular homes. Criteria and indicator development and calculation, benchmark scale establishment, quantitative and qualitative data collection from literature and surveys, and multi-criteria decision analysis are unique aspects of this framework. The results of the two case studies located in the Okanagan region, Canada showed that modular homes perform at a higher level of sustainability than their conventional counterparts across multiple metrics and levels related to environmental and economic factors. The modular homes scored eco-efficiency values of 62.5 and 56.0, respectively and fell into higher performance range. The proposed framework offers flexibility in examining different dimensions of sustainability, providing valuable insights into the key parameters that need to be addressed to enhance overall sustainability. This research, which integrates life cycle thinking and decision-making, helps the construction industry and, municipalities, governments, and policymakers in making informed decisions on the selection of suitable construction methods in city developments and move towards a more resilient and sustainable sector.</div></div>","PeriodicalId":101077,"journal":{"name":"Resilient Cities and Structures","volume":"4 2","pages":"Pages 46-68"},"PeriodicalIF":0.0,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855888","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 : 2025-04-18DOI: 10.1016/j.rcns.2025.03.003
Alaa Al Hawarneh , M. Shahria Alam , Rajeev Ruparathna , Stavroula J. Pantazopoulou
Given the growing emphasis on life-cycle analysis in bridge design, the design community is transitioning from the concept of performance-based design in structural engineering to a performance-based design approach within a life-cycle context. This approach considers various indicators, including cost, environmental impact, and societal factors when designing bridges. This shift enables a comprehensive assessment of structural resilience by examining the bridge's ability to endure various hazards throughout its lifespan. This study provides a comprehensive review of two key research domains that have emerged in the field of bridge life-cycle analysis, namely life-cycle sustainability (LCS) and life-cycle performance (LCP). The discussion on the LCS of bridges encompasses both assessment-based and optimization-based studies, while the exploration of LCP focuses on research examining structures subjected to deterioration over their service life due to deprecating phenomena such as corrosion and relative humidity changes, as well as extreme hazards like earthquakes and floods. Moreover, this study discusses the integration between LCS and LCP, highlighting how combined consideration of these factors can minimize damage costs, improve resiliency, and extend the lifespan of the structure. A detailed evaluation encompasses various life-cycle metrics, structural performance indicators, time-dependent modelling techniques, and analysis methods proposed in the literature. Additionally, the research identifies critical gaps and trends in life-cycle analysis within the realm of bridge engineering, providing a concise yet thorough overview for advancing considerations in the life-cycle design of bridges.
{"title":"Life-cycle thinking and performance-based design of bridges: A state-of-the-art review","authors":"Alaa Al Hawarneh , M. Shahria Alam , Rajeev Ruparathna , Stavroula J. Pantazopoulou","doi":"10.1016/j.rcns.2025.03.003","DOIUrl":"10.1016/j.rcns.2025.03.003","url":null,"abstract":"<div><div>Given the growing emphasis on life-cycle analysis in bridge design, the design community is transitioning from the concept of performance-based design in structural engineering to a performance-based design approach within a life-cycle context. This approach considers various indicators, including cost, environmental impact, and societal factors when designing bridges. This shift enables a comprehensive assessment of structural resilience by examining the bridge's ability to endure various hazards throughout its lifespan. This study provides a comprehensive review of two key research domains that have emerged in the field of bridge life-cycle analysis, namely life-cycle sustainability (LCS) and life-cycle performance (LCP). The discussion on the LCS of bridges encompasses both assessment-based and optimization-based studies, while the exploration of LCP focuses on research examining structures subjected to deterioration over their service life due to deprecating phenomena such as corrosion and relative humidity changes, as well as extreme hazards like earthquakes and floods. Moreover, this study discusses the integration between LCS and LCP, highlighting how combined consideration of these factors can minimize damage costs, improve resiliency, and extend the lifespan of the structure. A detailed evaluation encompasses various life-cycle metrics, structural performance indicators, time-dependent modelling techniques, and analysis methods proposed in the literature. Additionally, the research identifies critical gaps and trends in life-cycle analysis within the realm of bridge engineering, providing a concise yet thorough overview for advancing considerations in the life-cycle design of bridges.</div></div>","PeriodicalId":101077,"journal":{"name":"Resilient Cities and Structures","volume":"4 2","pages":"Pages 30-45"},"PeriodicalIF":0.0,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143843196","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 : 2025-04-12DOI: 10.1016/j.rcns.2025.03.004
Rajnil Lal, Ashkan Hashemi, Pierre Quenneville
Platform-style construction is a widely recognized and well-established approach among engineers and developers for multi-story mass timber buildings. This construction method offers many advantages, such as rapid assembly, an excellent strength-to-weight ratio, and appealing aesthetic features. In a platform-type construction, each story is constructed by placing the floor panels on top of the load-bearing wall, creating a platform for the level above. Although this method offers numerous advantages, recent research findings have revealed that cross-laminated (CLT) platform buildings with conventional connections, such as wall-to-floor hold-down brackets and shear connectors with nails and screws, are prone to experience a high degree of damage under design-level earthquakes. Consequently, conventional connections in platform-type construction are vulnerable to more damage under aftershocks and do not meet the damage avoidance requirements of seismic design. This paper introduces an innovative floor-to-wall connection for a platform-type low-rise mass timber building that mitigates the limitations of conventional connections. The effectiveness of the proposed connection has been investigated, and the seismic performance of the system, which incorporates the proposed connection, has been outlined in this paper. A numerical model with an innovative inter-story isolation system is developed in ETABS, and the seismic performance of the isolated structure was evaluated using Response Spectrum Analysis (RSA) and Nonlinear Time History Analysis (NLTHA). This study revealed that inter-story isolation systems significantly reduced the seismic demands on the mass timber components, demonstrating the system's ability to dissipate seismic energy. Additionally, the system displayed effective energy dissipation while exhibiting self-centering behaviour.
{"title":"An innovative connection system for platform-type mass timber buildings","authors":"Rajnil Lal, Ashkan Hashemi, Pierre Quenneville","doi":"10.1016/j.rcns.2025.03.004","DOIUrl":"10.1016/j.rcns.2025.03.004","url":null,"abstract":"<div><div>Platform-style construction is a widely recognized and well-established approach among engineers and developers for multi-story mass timber buildings. This construction method offers many advantages, such as rapid assembly, an excellent strength-to-weight ratio, and appealing aesthetic features. In a platform-type construction, each story is constructed by placing the floor panels on top of the load-bearing wall, creating a platform for the level above. Although this method offers numerous advantages, recent research findings have revealed that cross-laminated (CLT) platform buildings with conventional connections, such as wall-to-floor hold-down brackets and shear connectors with nails and screws, are prone to experience a high degree of damage under design-level earthquakes. Consequently, conventional connections in platform-type construction are vulnerable to more damage under aftershocks and do not meet the damage avoidance requirements of seismic design. This paper introduces an innovative floor-to-wall connection for a platform-type low-rise mass timber building that mitigates the limitations of conventional connections. The effectiveness of the proposed connection has been investigated, and the seismic performance of the system, which incorporates the proposed connection, has been outlined in this paper. A numerical model with an innovative inter-story isolation system is developed in ETABS, and the seismic performance of the isolated structure was evaluated using Response Spectrum Analysis (RSA) and Nonlinear Time History Analysis (NLTHA). This study revealed that inter-story isolation systems significantly reduced the seismic demands on the mass timber components, demonstrating the system's ability to dissipate seismic energy. Additionally, the system displayed effective energy dissipation while exhibiting self-centering behaviour.</div></div>","PeriodicalId":101077,"journal":{"name":"Resilient Cities and Structures","volume":"4 2","pages":"Pages 14-29"},"PeriodicalIF":0.0,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143824686","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 : 2025-04-12DOI: 10.1016/j.rcns.2025.03.002
Prerna Singh , Adjo Amekudzi-Kennedy , Baabak Ashuri , Ty Parrillo , Derek Rizzi , Russell Clark , Brian Woodall , Heejun Chang
The negative impacts of natural hazards on communities at all scales have been increasing. Floods comprise one such natural hazard that has emerged as one of the most destructive in the US and worldwide. While a lot of damage is estimated in terms of the cost of rebuilding infrastructure and direct loss of economy, the negative impacts of such disruptions go beyond the physical infrastructure. The impact on (and of) the social and institutional framework is rarely examined in conjunction with the physical and technical aspects. This paper examines flood vulnerability and risk of a community at an intersection of social, ecological, technical, and intuitional perspectives, and presents a framework for a holistic flood vulnerability and risk assessment that has a strong foundation in all four aspects of a resilient community. The study builds on the existing risk, vulnerability, and hazard assessment approaches, and refines them with a holistic perspective. The study uses a mixed method approach with qualitative and quantitative methodologies to assess flood occurrence probabilities, vulnerability, and risk from the social, ecological, technical, and institutional perspectives. A case study of the City of Atlanta is conducted using the framework to assess the overall vulnerability and risk of the city. The results of this analysis show that the regions that have the highest probability of flood hazard occurrence also appear to have the highest social, ecological, and technical vulnerabilities in the Atlanta area. While the results are intuitive, the applications support a focus on holistic resilience building across these four criteria. This study is potentially useful to practitioners, researchers, government agencies, and community organizations working to mitigate flood risk particularly as this risk continues to evolve with the changing climate.
{"title":"Case study of flood risk and vulnerability in the city of Atlanta – A social, economic, technical, and institutional perspective","authors":"Prerna Singh , Adjo Amekudzi-Kennedy , Baabak Ashuri , Ty Parrillo , Derek Rizzi , Russell Clark , Brian Woodall , Heejun Chang","doi":"10.1016/j.rcns.2025.03.002","DOIUrl":"10.1016/j.rcns.2025.03.002","url":null,"abstract":"<div><div>The negative impacts of natural hazards on communities at all scales have been increasing. Floods comprise one such natural hazard that has emerged as one of the most destructive in the US and worldwide. While a lot of damage is estimated in terms of the cost of rebuilding infrastructure and direct loss of economy, the negative impacts of such disruptions go beyond the physical infrastructure. The impact on (and of) the social and institutional framework is rarely examined in conjunction with the physical and technical aspects. This paper examines flood vulnerability and risk of a community at an intersection of social, ecological, technical, and intuitional perspectives, and presents a framework for a holistic flood vulnerability and risk assessment that has a strong foundation in all four aspects of a resilient community. The study builds on the existing risk, vulnerability, and hazard assessment approaches, and refines them with a holistic perspective. The study uses a mixed method approach with qualitative and quantitative methodologies to assess flood occurrence probabilities, vulnerability, and risk from the social, ecological, technical, and institutional perspectives. A case study of the City of Atlanta is conducted using the framework to assess the overall vulnerability and risk of the city. The results of this analysis show that the regions that have the highest probability of flood hazard occurrence also appear to have the highest social, ecological, and technical vulnerabilities in the Atlanta area. While the results are intuitive, the applications support a focus on holistic resilience building across these four criteria. This study is potentially useful to practitioners, researchers, government agencies, and community organizations working to mitigate flood risk particularly as this risk continues to evolve with the changing climate.</div></div>","PeriodicalId":101077,"journal":{"name":"Resilient Cities and Structures","volume":"4 2","pages":"Pages 1-13"},"PeriodicalIF":0.0,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143824685","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 : 2025-03-01DOI: 10.1016/j.rcns.2025.02.003
Sasa Cao , Osman E. Ozbulut
When a coin is tossed to a gravity well, it will spiral instead of falling directly to the center. Inspired by this phenomenon, a gravity well-inspired double friction pendulum system (GW-DFPS) is developed to extend the length of sliding trajectories of bridge superstructures during pulse-like near-fault earthquakes. As a result, a greater amount of energy will be dissipated due to the frictional sliding of the isolators. The GW-DFPS consists of a spherical surface and an outer surface described by a 1/x or logarithmic function to build gravity well. Full-scale isolators were fabricated and their response was characterized considering various parameters such as the friction material of slider, surface roughness of sliding surfaces, and applied vertical loads. Additionally, a finite element model of the isolator was created using the experimental test data. Numerical simulations were performed on a case-study bridge structure isolated using both a conventional DFPS system and the proposed GW-DFPS systems. The experimental results reveal that the proposed isolators exhibit stable response under vertical loads varying from 200 kN to 1000 kN with a negative stiffness response when the isolator slides at the outer sliding surface. The numerical simulations of the selected bridge structure demonstrate that the GW-DFPS significantly extends the sliding trajectory lengths of the superstructure during half of the earthquake pulses, resulting in increased energy dissipation during this interval. The kinetic energies of the bridge isolated by GW-DFPS are consistently lower than those of the bridge isolated by the other two kinds of isolators, resulting lower shear forces on the bridge.
{"title":"Gravity well-inspired double friction pendulum system for bridges under pulse-like near-fault earthquakes","authors":"Sasa Cao , Osman E. Ozbulut","doi":"10.1016/j.rcns.2025.02.003","DOIUrl":"10.1016/j.rcns.2025.02.003","url":null,"abstract":"<div><div>When a coin is tossed to a gravity well, it will spiral instead of falling directly to the center. Inspired by this phenomenon, a gravity well-inspired double friction pendulum system (GW-DFPS) is developed to extend the length of sliding trajectories of bridge superstructures during pulse-like near-fault earthquakes. As a result, a greater amount of energy will be dissipated due to the frictional sliding of the isolators. The GW-DFPS consists of a spherical surface and an outer surface described by a 1/<em>x</em> or logarithmic function to build gravity well. Full-scale isolators were fabricated and their response was characterized considering various parameters such as the friction material of slider, surface roughness of sliding surfaces, and applied vertical loads. Additionally, a finite element model of the isolator was created using the experimental test data. Numerical simulations were performed on a case-study bridge structure isolated using both a conventional DFPS system and the proposed GW-DFPS systems. The experimental results reveal that the proposed isolators exhibit stable response under vertical loads varying from 200 kN to 1000 kN with a negative stiffness response when the isolator slides at the outer sliding surface. The numerical simulations of the selected bridge structure demonstrate that the GW-DFPS significantly extends the sliding trajectory lengths of the superstructure during half of the earthquake pulses, resulting in increased energy dissipation during this interval. The kinetic energies of the bridge isolated by GW-DFPS are consistently lower than those of the bridge isolated by the other two kinds of isolators, resulting lower shear forces on the bridge.</div></div>","PeriodicalId":101077,"journal":{"name":"Resilient Cities and Structures","volume":"4 1","pages":"Pages 83-100"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Glue-laminated timber (GLT) is an engineered wood product widely used in mass timber construction for its strong structural and fire-resistant properties. However, the fire performance of GLT varies significantly due to the natural and uncertain phenomena (moisture, exposure time, isotropic, homogenous properties, etc.) of fire and timber. This makes it difficult to predict the fire behaviour of the GLT structural elements. To ensure building safety, it is crucial to assess GLT's fire behaviour and post-fire structural integrity during the design stages. This study conducted the experimental tests of GLT beams (280 mm × 560 mm) without loading (1.4 m) and under a four-point bending load (5.4 m). Tests identified thermal behaviour and charring rates of GLT beam. Then, the residual stiffness of the GLT beam was calculated, and the charring rates of the beams were compared with Australian and European standards. Reliability analysis was conducted for beams for a fire exposure of 120 min, considering the charring rates observed through the analysis and simulating the fire insulations. Results show that the charring rate of GLT made with spruce pine timber varied between 0.43 and 0.81 mm/min, with a mean rate of 0.7 mm/min, aligning with both Australian and European standards. However, considering timber density and moisture content, the charring rates in Australian standards were conservative. The study also found that structural capacity significantly degrades under fire, with a 22 % reduction in flexural stiffness after 120 min of exposure. Additionally, GLT beams can safely function for 30 min under 75 % of their design moment capacity and for 60 min under 50 % capacity.
{"title":"Experimental and reliability assessment of fire resistance of glue laminated timber beams","authors":"Satheeskumar Navaratnam , Thisari Munmulla , Pathmanthan Rajeev , Thusiyanthan Ponnampalam , Solomon Tesfamariam","doi":"10.1016/j.rcns.2025.02.004","DOIUrl":"10.1016/j.rcns.2025.02.004","url":null,"abstract":"<div><div>Glue-laminated timber (GLT) is an engineered wood product widely used in mass timber construction for its strong structural and fire-resistant properties. However, the fire performance of GLT varies significantly due to the natural and uncertain phenomena (moisture, exposure time, isotropic, homogenous properties, etc.) of fire and timber. This makes it difficult to predict the fire behaviour of the GLT structural elements. To ensure building safety, it is crucial to assess GLT's fire behaviour and post-fire structural integrity during the design stages. This study conducted the experimental tests of GLT beams (280 mm × 560 mm) without loading (1.4 m) and under a four-point bending load (5.4 m). Tests identified thermal behaviour and charring rates of GLT beam. Then, the residual stiffness of the GLT beam was calculated, and the charring rates of the beams were compared with Australian and European standards. Reliability analysis was conducted for beams for a fire exposure of 120 min, considering the charring rates observed through the analysis and simulating the fire insulations. Results show that the charring rate of GLT made with spruce pine timber varied between 0.43 and 0.81 mm/min, with a mean rate of 0.7 mm/min, aligning with both Australian and European standards. However, considering timber density and moisture content, the charring rates in Australian standards were conservative. The study also found that structural capacity significantly degrades under fire, with a 22 % reduction in flexural stiffness after 120 min of exposure. Additionally, GLT beams can safely function for 30 min under 75 % of their design moment capacity and for 60 min under 50 % capacity.</div></div>","PeriodicalId":101077,"journal":{"name":"Resilient Cities and Structures","volume":"4 1","pages":"Pages 101-114"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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