This study develops a comprehensive framework to assess the resilience of transportation networks consisting of deteriorating bridges subjected to earthquake events.For this purpose,the structural capacity of highway ...This study develops a comprehensive framework to assess the resilience of transportation networks consisting of deteriorating bridges subjected to earthquake events.For this purpose,the structural capacity of highway bridges is estimated during their service life using a set of detailed finite-element models that simulate the progress of deterioration.The developed models take into consideration the main environmental stressors and determine the extent of capacity loss as a function of time.Based on the degraded state of structural components,seismic fragility analyses are performed to obtain a probabilistic evaluation of the extent of damageability of the existing bridges under seismic events.Since each transportation link normally consists of a number of bridges,the state of damage in the individual bridges is mapped to the corresponding links and a scenario-based approach is employed to estimate the resilience of the entire transportation network.To demonstrate how the consequences of structural degradation can be integrated into the developed framework,the large-scale transportation network of Los Angeles and Orange counties is investigated under a series of aging and earthquake scenarios.The outcome of this study indicates how the estimates associated with the functionality measures of a transportation network can be improved if the age factor is properly integrated into the framework used for resilience assessment.展开更多
Majority of the highly populated regions of the United States are susceptible to multiple natural hazards.In such regions,the design and construction of structures under multiple hazards are critical to achieve the ap...Majority of the highly populated regions of the United States are susceptible to multiple natural hazards.In such regions,the design and construction of structures under multiple hazards are critical to achieve the appropriate structural performance and infrastructure resilience.Multi-hazard reliability analysis of structural systems evaluates the system response under multiple random loads,some of which may occur simultaneously,or the effect of one may weaken the structural system before the occurrence of the next event.This paper studies the combined effects of scouring and earthquakes,as two uncorrelated extreme events,on the performance of reinforced concrete highway bridges.In a continuous effort to support future improvement in understanding the impact of multi-hazard loading scenario on bridges and to develop mitigation actions,this paper assesses the seismic vulnerability of a reinforced concrete highway bridge experiencing the effect of erosion due to the increase in frequency of flood events.The analytical fragility approach uses a three-dimensional nonlinear finite element model of the bridge cases with various levels of scouring.Because a bridge is system of components,a component level fragility curve is used to track the response of the components for a given ground motion intensity.The system fragility curves are developed to consider the vulnerability of critical components to assess the probability of bridge damage.The results indicate that under multi-hazard scenarios,the component governing the fragility of the bridge system varies depending on the level of scour sustained by the structure.展开更多
The resilience of our cityscapes hinges not only on the performance of individual structures and infrastructure but also on the strength of social,economic,and public institutions.These elements are vital for planning...The resilience of our cityscapes hinges not only on the performance of individual structures and infrastructure but also on the strength of social,economic,and public institutions.These elements are vital for planning and mitigation design before disasters,immediate disaster re-sponse and the long-term recovery of communities.The built environ-ment,which underpins the daily activities and overall well-being of communities,faces a myriad of natural hazards.展开更多
基金partially sponsored by the National Science Foundation(NSF)under Grants No.2125426.
文摘This study develops a comprehensive framework to assess the resilience of transportation networks consisting of deteriorating bridges subjected to earthquake events.For this purpose,the structural capacity of highway bridges is estimated during their service life using a set of detailed finite-element models that simulate the progress of deterioration.The developed models take into consideration the main environmental stressors and determine the extent of capacity loss as a function of time.Based on the degraded state of structural components,seismic fragility analyses are performed to obtain a probabilistic evaluation of the extent of damageability of the existing bridges under seismic events.Since each transportation link normally consists of a number of bridges,the state of damage in the individual bridges is mapped to the corresponding links and a scenario-based approach is employed to estimate the resilience of the entire transportation network.To demonstrate how the consequences of structural degradation can be integrated into the developed framework,the large-scale transportation network of Los Angeles and Orange counties is investigated under a series of aging and earthquake scenarios.The outcome of this study indicates how the estimates associated with the functionality measures of a transportation network can be improved if the age factor is properly integrated into the framework used for resilience assessment.
基金supported by the Iowa Department of Transportation and Midwest Transportation Center.
文摘Majority of the highly populated regions of the United States are susceptible to multiple natural hazards.In such regions,the design and construction of structures under multiple hazards are critical to achieve the appropriate structural performance and infrastructure resilience.Multi-hazard reliability analysis of structural systems evaluates the system response under multiple random loads,some of which may occur simultaneously,or the effect of one may weaken the structural system before the occurrence of the next event.This paper studies the combined effects of scouring and earthquakes,as two uncorrelated extreme events,on the performance of reinforced concrete highway bridges.In a continuous effort to support future improvement in understanding the impact of multi-hazard loading scenario on bridges and to develop mitigation actions,this paper assesses the seismic vulnerability of a reinforced concrete highway bridge experiencing the effect of erosion due to the increase in frequency of flood events.The analytical fragility approach uses a three-dimensional nonlinear finite element model of the bridge cases with various levels of scouring.Because a bridge is system of components,a component level fragility curve is used to track the response of the components for a given ground motion intensity.The system fragility curves are developed to consider the vulnerability of critical components to assess the probability of bridge damage.The results indicate that under multi-hazard scenarios,the component governing the fragility of the bridge system varies depending on the level of scour sustained by the structure.
文摘The resilience of our cityscapes hinges not only on the performance of individual structures and infrastructure but also on the strength of social,economic,and public institutions.These elements are vital for planning and mitigation design before disasters,immediate disaster re-sponse and the long-term recovery of communities.The built environ-ment,which underpins the daily activities and overall well-being of communities,faces a myriad of natural hazards.
