Resilient smart urban water distribution networks are essential to ensure smooth urban operation and maintain daily water services.However,the dynamics and complexity of smart water distribution networks make its re-s...Resilient smart urban water distribution networks are essential to ensure smooth urban operation and maintain daily water services.However,the dynamics and complexity of smart water distribution networks make its re-silience study face many challenges.The introduction of digital twin technology provides an innovative solution for the resilience study of smart water distribution networks,which can more effectively support the network’s real-time monitoring and intelligent control.This paper proposes a digital twin architecture of smart water dis-tribution networks,laying the foundation for the resilience assessment of water distribution networks.Based on this,a performance evaluation model based on user satisfaction is proposed,which can more intuitively and effectively reflect the performance of urban water supply services.Meanwhile,we propose a method to quantify the importance of water distribution pipes’residual resilience,considering the time value to optimize the re-covery sequence of failed pipes and develop targeted preventive maintenance strategies.Finally,to validate the effectiveness of the proposed method,this paper applies it to a water distribution network.The results show that the proposed method can significantly improve the resilience and enhance the overall resilience of smart urban water distribution networks.展开更多
This paper aims to evaluate the stochastic response of steel columns subjected to blast loads using the modified single degree of freedom(MSDOF)method,which assessed towards the conventional single degree of freedom(S...This paper aims to evaluate the stochastic response of steel columns subjected to blast loads using the modified single degree of freedom(MSDOF)method,which assessed towards the conventional single degree of freedom(SDOF)and the experimentally validated Finite Element(FE)methods(LSDYNA).For this purpose,special atten-tion is given to calculating the response of H-shaped steel columns under blast.The damage amount is determined based on the support rotation criterion,which is expressed as a function of their maximum lateral mid-span dis-placement.To account for uncertainties in input parameters and obtain the failure probability,the Monte Carlo simulation(MCS)method is employed,complemented by the Latin Hypercube Sampling(LHS)method to reduce the number of simulations.A parametric analysis is hence performed to examine the effect of several input pa-rameters(including both deterministic and probabilistic parameters)on the probability of column damage as a function of support rotation.First,the MSDOF method confirms its higher accuracy in estimating the probability of column damage due to blast,compared to the conventional SDOF.The collected results also show that un-certainties of several input parameters have significant effects on the column behavior.In particular,geometric parameters(including cross-sectional characteristics,boundary conditions and column length)have major effect on the corresponding column response,in the same way of input blast load parameters and material properties.展开更多
The efficient transportation of goods is vital for the economic growth of communities,making developing and maintaining seaport infrastructure an essential component of the marine transportation system.Given their geo...The efficient transportation of goods is vital for the economic growth of communities,making developing and maintaining seaport infrastructure an essential component of the marine transportation system.Given their geographic locations,ports are consistently at risk from natural hazards,making the resilience of port infrastructure an essential goal.Despite considerable progress in resilience research,there remains a gap in methods tailored explicitly to assessing port resilience,particularly under extreme wind events.Current approaches often do not capture the full complexity of port systems,as they tend to focus on isolated aspects,such as structural resilience.This paper introduces the PORT Resilience Framework,addressing these gaps by evaluating resilience through a comprehensive list of indicators gathered from various legitimate sources.The indicators are then organized under four comprehensive resilience dimensions:Physical Infrastructure,ICT(i.e.,Information and Communication Technology)and Equipment;Organization and Business Management;Resources and Economic Development;and Territory,Environment,and Stakeholders.This classification is summarized under the acronym"PORT."This paper also introduces a method for aggregating resilience indicators by considering their performance before and after a specific hazard,transforming the data into a quantifiable Loss of Resilience index.The approach is applied to a case study,assessing the resilience of a real Terminal against wind action using real data sourced from the port management.The case study analysis revealed that human resources and quay operations were the most critical factors affecting recovery,with insufficient staffing leading to prolonged recovery periods.The study further demonstrated that post-disruption activity surges,captured by different serviceability function methodologies,often created operational bottlenecks,challenging the port's overall recovery.展开更多
Resilience studies for water distribution systems(WDS)coupled with other interdependent infrastructure systems attract increasing attention from stakeholders and researchers.However,most existing large-scale WDS model...Resilience studies for water distribution systems(WDS)coupled with other interdependent infrastructure systems attract increasing attention from stakeholders and researchers.However,most existing large-scale WDS models are single infrastructure-based without consideration of other infrastructure systems.This is due to a lack of needed information on systems coupling,the structure of the simulator used,and the computation load involved.To address these gaps,this paper presents a synthetic modeling framework for a real-world WDS as coordinating with other infrastructure systems via a building-mediated clustering approach through consideration of physical distance and node capacity.First,the WDS network topology and operation parameters are inferred via bulk open-source information.A building-mediated clustering approach is designed to systematically derive the interdependence between the WDS and the power system similarly created as a case study.Second,a novel linearization method is developed in formulating the WDS model that can relieve computation load while maintaining accuracy.Finally,a disruption-recovery framework is developed to demonstrate the proposed methodology in modelling WDS resilience.The framework is applied to a neighborhood in Queenstown,Singapore,an area of 20.43 km^(2) and 96,000 population.The near-real-time simulations on the coupled system involving 308 nodes and 384 links showcase the effectiveness and application of the proposed synthetic modeling and formulation.展开更多
The authors regret that the original publication of this paper did not include Jawad Fayaz as a co-author.After further discussions and a thorough review of the research contributions,it was agreed that his significan...The authors regret that the original publication of this paper did not include Jawad Fayaz as a co-author.After further discussions and a thorough review of the research contributions,it was agreed that his significant contributions to the foundational aspects of the research warranted recognition,and he has now been added as a co-author.展开更多
This study numerically investigates the seismic response of a nine-story self-centering concentrically braced frame building incorporating force-limiting connections between the floor system and the lateral force-resi...This study numerically investigates the seismic response of a nine-story self-centering concentrically braced frame building incorporating force-limiting connections between the floor system and the lateral force-resisting system.Nonlinear earthquake simulations are conducted under design basis earthquake ground motions,and the results are compared against a baseline model with rigid-elastic connections.The study discusses connection design considerations and evaluates the effectiveness of force-limiting connections in mitigating higher-mode effects.The findings show that force-limiting connections significantly reduce the magnitude and variability of floor accelerations,brace forces,and connection forces,while maintaining comparable story drifts.limiting Force-connections primarily reduce the contribution of higher-mode responses,while the controlled rocking base mechanism modifies the first-mode response.Overall,the reduced dispersion in structural response improves the reliability of seismic design and enhances resilience by minimizing damage to both structural components and acceleration-sensitive nonstructural elements.展开更多
The September 2017 earthquakes in Mexico,which struck within a twelve-day span and affected regions with vastly different seismic,socioeconomic,and urban characteristics,revealed the multifactorial nature of seismic v...The September 2017 earthquakes in Mexico,which struck within a twelve-day span and affected regions with vastly different seismic,socioeconomic,and urban characteristics,revealed the multifactorial nature of seismic vulnerability and resilience in the country.This paper provides a comprehensive review of the damage on the built environment,emergency response,recovery and reconstruction efforts,regulatory evolution,and institu-tional reforms that followed these events.Key topics include the performance of self-built housing and essential infrastructure,the challenges of decentralized building codes and their uneven development and enforcement,the role of civil society,private sector and media in disaster response,and the implementation of the National Reconstruction Program.Advances in seismic code development-particularly the updated Complementary Technical Norms(CTNs)of Mexico City-and the creation of a dedicated standard for the evaluation and rehabilitation of existing buildings are also discussed.The proposed Construction Law for Mexico City,which aims to assign legal responsibility to stakeholders and formalize the regulatory framework,may serve as a legislative model for other regions.The paper concludes by highlighting the importance of coordination,tech-nical rigor,equity and inclusion in recovery and reconstruction,and public engagement in advancing seismic resilience across diverse urban,semi-urban and rural contexts.展开更多
Investing in disaster risk reduction is crucial for minimizing the impacts of disasters.However,little is known about the factors that influence changes in investment levels over time.This study aims to identify the k...Investing in disaster risk reduction is crucial for minimizing the impacts of disasters.However,little is known about the factors that influence changes in investment levels over time.This study aims to identify the key socio-economic drivers behind increases and decreases in flood protection investment in People’s Republic of China(PRC).Such information is crucial for policy makers to justify flood investments.By analyzing data on flood protection expenditures,economic losses from floods,and other relevant indicators from 1980 to 2020,the study evaluates the relationship between investment and disaster impacts through the lens of the flood investment cycle model.It was found that the country succeeded in reducing flood damage because of increasing investment in flood protection.The results indicate that changes in PRC’s flood protection investment have been driven by three major factors:the occurrence of major disasters,the fiscal situation,and shifts in government policies.Investment tended to increase following large-scale events,such as the 1998 Yangtze River Basin flood and the 2008 Wenchuan earthquake,which prompted policy changes and renewed focus on DRR measures.Fiscal constraints limited investment in the 1990s,but reforms and stimulus measures improved the financial situation,enabling increased spending on flood protection.PRC’s experience in steadily reducing flood damage through sustained investment and policy commitment offers valuable lessons for other developing countries facing similar challenges.展开更多
Reconstruction of buildings in the Christchurch central business district following the 2011 earthquake has been a massive undertaking that is not yet completed.Interviews have been conducted with representatives of t...Reconstruction of buildings in the Christchurch central business district following the 2011 earthquake has been a massive undertaking that is not yet completed.Interviews have been conducted with representatives of the consulting engineering companies who designed 55 of these buildings from 2017 until 2025 to determine:(i)the building construction materials and structural system types used,and(ii)the drivers for the selection of these systems.The information obtained is compared with a 2017 survey,by the authors,with the same design companies for buildings constructed from 2012 to 2017,as part of the Christchurch rebuild after the 2010-2011 Canterbury earthquakes.It is found that 47%and 45%of the buildings constructed had steel and concrete lateral force resisting systems,respectively,with the remainder using timber.In terms of floor space areas,the steel buildings were typically larger and the ratios were 70%and 24%,respectively.The most popular structural steel seismic systems were MRFs and BRBFs with 29%and 20%of the floor areas,respectively.Gravity systems,when needed,were generally steel.Although slightly different,these numbers are similar in magnitude to those reported in the prior study.However,comparing the factors driving choice of structure systems reported in the previous study,many of the engineers interviewed commented that,as the Canterbury earthquakes became further away in time,fewer of their clients requested resilient designs that would help achieve functionality(e.g.,maintain business continuity)following future earthquakes,requesting instead lowest-cost designs.Nonetheless,it is expected that much of the newer construction will provide improvements in seismic performance given that many buildings were designed for significantly higher strength and lower drift than permitted in the standards.展开更多
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 t...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.展开更多
During the M_(w)=7.1 September 19,2017 earthquake with epicenter nearby the boundary of Puebla and Morelos states,an important amount of structural damage occurred in Mexico City,120 km away from the epicenter.Among t...During the M_(w)=7.1 September 19,2017 earthquake with epicenter nearby the boundary of Puebla and Morelos states,an important amount of structural damage occurred in Mexico City,120 km away from the epicenter.Among the most severely affected sectors was the housing sector.At least 16 houses collapsed or partially collapsed during the earthquake,more than 5100 were demolished with public funds and more than 5800 were sternly damaged and required to be rehabilitated.Close to 1300 apartment buildings were severely damaged,where 33 of them collapsed or partially collapsed.Then,the recovery of the housing sector,which is instrumental for both the social and economy recovery of the city,have posed a monumental task and challenge to the citizens and authorities of Mexico City.In this paper,the author summarizes how these efforts to recover the affected housing sector have been in Mexico City close to eight years after the 9/19/2017 earthquake,based upon detailed statistics and information compiled by the author from different sources.It can be concluded that after 7+years,the recovery process of single-family houses has been a success,as close to 100%of the affected homes have been fully recovered with much better projects than the originally damaged.However,the recovery process of apartment buildings,although important,still has a long way to go.As of May 2025,only 59.6%of the affected buildings have been fully recovered(31.3%using public funds),other 11.3%are under construction or rehabilitation process and,in 29.1%of the affected buildings,no action has been taken to speed their recovery.展开更多
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 wi...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 exam-ining 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 analy-sis 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 con-siderations in the life-cycle design of bridges.展开更多
This study developed a digital twin(DT)and structural health monitoring(SHM)system for a balanced cantilever bridge,utilizing advanced measurement techniques to enhance accuracy.Vibration and dynamic strain measuremen...This study developed a digital twin(DT)and structural health monitoring(SHM)system for a balanced cantilever bridge,utilizing advanced measurement techniques to enhance accuracy.Vibration and dynamic strain measurements were obtained using accelerometers and piezo-resistive strain gauges,capturing low-magnitude dynamic strains during operational vibrations.3D-LiDAR scanning and Ultrasonic Pulse Velocity(UPV)tests captured the bridge's as-is geometry and modulus of elasticity.The resulting detailed 3D point cloud model revealed the structure's true state and highlighted discrepancies between the as-designed and as-built conditions.Dynamic properties,including modal frequencies and shapes,were extracted from the strain and acceleration measurements,providing critical insights into the bridge's structural behavior.The neutral axis depth,indicating stress distribution and potential damage,was accurately determined.Good agreement between vibration measurement data and the as-is model results validated the reliability of the digital twin model.Dynamic strain patterns and neutral axis parameters showed strong correlation with model predictions,serving as sensitive indicators of local damage.The baseline digital twin model and measurement results establish a foundation for future bridge inspections and investigations.This study demonstrates the effectiveness of combining digital twin technology with field measurements for real-time monitoring and predictive maintenance,ensuring the sustainability and safety of the bridge infrastructure,thereby enhancing its overall resilience to operational and environmental stressors.展开更多
Flooding has become an emerging global catastrophe,generating considerable damage to both infrastructures and lives.Despite the critical need for quantitative assessments of both flood damage and the effectiveness of ...Flooding has become an emerging global catastrophe,generating considerable damage to both infrastructures and lives.Despite the critical need for quantitative assessments of both flood damage and the effectiveness of flood mitigation measures,most existing studies have focused on isolated aspects of flood risk.Only a very limited number of studies have comprehensively integrated hazard mapping,hydrodynamic simulations,and economic damage estimations to evaluate the real-world impact and effectiveness of flood mitigation measures(FMMs).This study presents a multi-method approach to evaluate the performance of such established structural FMMs.Initially,hazard assessments for two selected case study areas,the Colombo Metropolitan Area in Sri Lanka and Auckland,New Zealand,two flood-prone cities with contrasting geographical contexts.Flood inundation mapping for the Madiwela South Diversion,Colombo,Sri Lanka,was performed using hydrodynamic modeling to demonstrate the reduction in flood inundation area and depth after the implementation of the measure,considering six(6)design return periods(RPs).Subsequently,tangible and intangible property damage estimations for“without FMMs”and“with FMMs”were evaluated to identify the benefit of responding to flood conditions,utilising a vulnerability-based economic analysis.In addition to damage estimations,the study adopts a novel approach by conducting an investment viability analysis to find the Benefit-to-Cost ratios and Net Present Value of nine(9)selected FMMs implemented by Sri Lanka Land Development Co-operation(SLLDC).The FMMs implemented by SLLDC were selected from Colombo,Sri Lanka.The quantified damage estimates revealed a reduction in flood damages ranging from 39%to 63%,alongside a decrease in flood inundation depths between 9%and 12%,and the results underscore the significant effectiveness of FMMs in managing urban flooding and minimising its impacts.This cross-disciplinary methodology enables a transferable framework for resilience-oriented urban planning in diverse hydrological and geographical contexts.展开更多
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 com...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 environ-ment,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.展开更多
While in the past the robustness of transportation networks was studied considering the cyber and physical space as isolated environments this is no longer the case.Integrating the Internet of Things devices in the se...While in the past the robustness of transportation networks was studied considering the cyber and physical space as isolated environments this is no longer the case.Integrating the Internet of Things devices in the sensing area of transportation infrastructure has resulted in ubiquitous cyber-physical systems and increasing interdependen-cies between the physical and cyber networks.As a result,the robustness of transportation networks relies on the uninterrupted serviceability of physical and cyber networks.Current studies on interdependent networks overlook the civil engineering aspect of cyber-physical systems.Firstly,they rely on the assumption of a uniform and strong level of interdependency.That is,once a node within a network fails its counterpart fails immedi-ately.Current studies overlook the impact of earthquake and other natural hazards on the operation of modern transportation infrastructure,that now serve as a cyber-physical system.The last is responsible not only for the physical operation(e.g.,flow of vehicles)but also for the continuous data transmission and subsequently the cy-ber operation of the entire transportation network.Therefore,the robustness of modern transportation networks should be modelled from a new cyber-physical perspective that includes civil engineering aspects.In this paper,we propose a new robustness assessment approach for modern transportation networks and their underlying in-terdependent physical and cyber network,subjected to earthquake events.The novelty relies on the modelling of interdependent networks,in the form of a graph,based on their interdependency levels.We associate the service-ability level of the coupled physical and cyber network with the damage states induced by earthquake events.Robustness is then measured as a degradation of the cyber-physical serviceability level.The application of the approach is demonstrated by studying an illustrative transportation network using seismic data from real-world transportation infrastructure.Furthermore,we propose the integration of a robustness improvement indicator based on physical and cyber attributes to enhance the cyber-physical serviceability level.Results indicate an improvement in robustness level(i.e.,41%)by adopting the proposed robustness improvement indicator.The usefulness of our approach is highlighted by comparing it with other methods that consider strong interdepen-dencies and key node protection strategies.The approach is of interest to stakeholders who are attempting to incorporate cyber-physical systems into civil engineering systems.展开更多
Recent research demonstrates the need for comprehensive frameworks to achieve an appropriate level of resilience(e.g.,energy,seismic)of the European building stock,through integrated retrofitting interventions.Differe...Recent research demonstrates the need for comprehensive frameworks to achieve an appropriate level of resilience(e.g.,energy,seismic)of the European building stock,through integrated retrofitting interventions.Different frameworks have been proposed to identify optimal interventions when several feasible alternatives are available,considering multiple decision variables of different nature,such as social,economic,or technical.Within these efforts and frameworks,less attention has been paid to the post-earthquake recovery time of buildings and communities,thus ignoring the significance of reaching a desired recovery state(e.g.,functional recovery)within a specified time frame.To overcome this limitation,this study estimates post-earthquake recovery times and uses them as one of the decision variables in multi-criteria identification of optimal retrofitting of an existing RC building.The case-study building is representative of the Italian school buildings constructed between the 1960s and 1970s and was analysed under two seismic hazard levels(moderate and high).Following the identification of the main structural deficiencies of the as-built structure through nonlinear static analyses,four seismic retrofit measures were selected.Then,the earthquake-induced downtime of each of the four retrofitted building configurations was assessed,analysing the different recovery times as a function of the seismic hazard level and the recovery state.A downtime-based metric,namely the expected annual downtime,was introduced as decision variable within an available multi-criteria decision-making framework to include the impact of downtime,rank the four retrofit measures and identify the preferable one.展开更多
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 l...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.展开更多
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 assem...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.展开更多
In the last two decades,seismic resilience(SR)has been developed as a main concept for the assessment of the structural vulnerabilities of buildings and city centres.In particular,historical centers consist of adjacen...In the last two decades,seismic resilience(SR)has been developed as a main concept for the assessment of the structural vulnerabilities of buildings and city centres.In particular,historical centers consist of adjacent buildings organized in blocks with common characteristics and similar typologies.The paper proposes a meth-odology to quantify SR for urban regions,by overcoming the state of the art studies that focus on assessing the SR for singular buildings.In this regard,the presented methodology may calculate the SR of blocks of buildings for the assessment of recovery investments of historical city centers.The main idea is to assess the level of vulnerability by accurate 3D surveys and visual inspections in order to select empirical fragility curves.The proposed methodology was herein applied to the city center of San Marino,designated by UNESCO as a world heritage site.展开更多
基金the financial support for this research from the Program for the Program for young backbone teachers in Universities of Henan Province(No.2021GGJS007).
文摘Resilient smart urban water distribution networks are essential to ensure smooth urban operation and maintain daily water services.However,the dynamics and complexity of smart water distribution networks make its re-silience study face many challenges.The introduction of digital twin technology provides an innovative solution for the resilience study of smart water distribution networks,which can more effectively support the network’s real-time monitoring and intelligent control.This paper proposes a digital twin architecture of smart water dis-tribution networks,laying the foundation for the resilience assessment of water distribution networks.Based on this,a performance evaluation model based on user satisfaction is proposed,which can more intuitively and effectively reflect the performance of urban water supply services.Meanwhile,we propose a method to quantify the importance of water distribution pipes’residual resilience,considering the time value to optimize the re-covery sequence of failed pipes and develop targeted preventive maintenance strategies.Finally,to validate the effectiveness of the proposed method,this paper applies it to a water distribution network.The results show that the proposed method can significantly improve the resilience and enhance the overall resilience of smart urban water distribution networks.
文摘This paper aims to evaluate the stochastic response of steel columns subjected to blast loads using the modified single degree of freedom(MSDOF)method,which assessed towards the conventional single degree of freedom(SDOF)and the experimentally validated Finite Element(FE)methods(LSDYNA).For this purpose,special atten-tion is given to calculating the response of H-shaped steel columns under blast.The damage amount is determined based on the support rotation criterion,which is expressed as a function of their maximum lateral mid-span dis-placement.To account for uncertainties in input parameters and obtain the failure probability,the Monte Carlo simulation(MCS)method is employed,complemented by the Latin Hypercube Sampling(LHS)method to reduce the number of simulations.A parametric analysis is hence performed to examine the effect of several input pa-rameters(including both deterministic and probabilistic parameters)on the probability of column damage as a function of support rotation.First,the MSDOF method confirms its higher accuracy in estimating the probability of column damage due to blast,compared to the conventional SDOF.The collected results also show that un-certainties of several input parameters have significant effects on the column behavior.In particular,geometric parameters(including cross-sectional characteristics,boundary conditions and column length)have major effect on the corresponding column response,in the same way of input blast load parameters and material properties.
文摘The efficient transportation of goods is vital for the economic growth of communities,making developing and maintaining seaport infrastructure an essential component of the marine transportation system.Given their geographic locations,ports are consistently at risk from natural hazards,making the resilience of port infrastructure an essential goal.Despite considerable progress in resilience research,there remains a gap in methods tailored explicitly to assessing port resilience,particularly under extreme wind events.Current approaches often do not capture the full complexity of port systems,as they tend to focus on isolated aspects,such as structural resilience.This paper introduces the PORT Resilience Framework,addressing these gaps by evaluating resilience through a comprehensive list of indicators gathered from various legitimate sources.The indicators are then organized under four comprehensive resilience dimensions:Physical Infrastructure,ICT(i.e.,Information and Communication Technology)and Equipment;Organization and Business Management;Resources and Economic Development;and Territory,Environment,and Stakeholders.This classification is summarized under the acronym"PORT."This paper also introduces a method for aggregating resilience indicators by considering their performance before and after a specific hazard,transforming the data into a quantifiable Loss of Resilience index.The approach is applied to a case study,assessing the resilience of a real Terminal against wind action using real data sourced from the port management.The case study analysis revealed that human resources and quay operations were the most critical factors affecting recovery,with insufficient staffing leading to prolonged recovery periods.The study further demonstrated that post-disruption activity surges,captured by different serviceability function methodologies,often created operational bottlenecks,challenging the port's overall recovery.
文摘Resilience studies for water distribution systems(WDS)coupled with other interdependent infrastructure systems attract increasing attention from stakeholders and researchers.However,most existing large-scale WDS models are single infrastructure-based without consideration of other infrastructure systems.This is due to a lack of needed information on systems coupling,the structure of the simulator used,and the computation load involved.To address these gaps,this paper presents a synthetic modeling framework for a real-world WDS as coordinating with other infrastructure systems via a building-mediated clustering approach through consideration of physical distance and node capacity.First,the WDS network topology and operation parameters are inferred via bulk open-source information.A building-mediated clustering approach is designed to systematically derive the interdependence between the WDS and the power system similarly created as a case study.Second,a novel linearization method is developed in formulating the WDS model that can relieve computation load while maintaining accuracy.Finally,a disruption-recovery framework is developed to demonstrate the proposed methodology in modelling WDS resilience.The framework is applied to a neighborhood in Queenstown,Singapore,an area of 20.43 km^(2) and 96,000 population.The near-real-time simulations on the coupled system involving 308 nodes and 384 links showcase the effectiveness and application of the proposed synthetic modeling and formulation.
文摘The authors regret that the original publication of this paper did not include Jawad Fayaz as a co-author.After further discussions and a thorough review of the research contributions,it was agreed that his significant contributions to the foundational aspects of the research warranted recognition,and he has now been added as a co-author.
基金financial support provided by Lehigh University,the Advanced Technology for Large Structural Systems(ATLSS)Engineering Research Center,and the Department of Structural Engineering at the University of California,San Diegolarge research team led by Professor Robert B.Fleischman under the project“NEESR:Inertial Force-Limiting Floor Anchorage Systems for Seismic Resistant Building Structures”with the support of grants from the National Science Foundation,award no.CMMI-1135033in the George E.Brown,Jr.Network for Earthquake gineering En-Simulation Research(NEESR)program and award no.CMMI-0402490 for the George E.Brown,Jr.Network for Earthquake ing Engineer-Simulation(NEES)consortium operations.
文摘This study numerically investigates the seismic response of a nine-story self-centering concentrically braced frame building incorporating force-limiting connections between the floor system and the lateral force-resisting system.Nonlinear earthquake simulations are conducted under design basis earthquake ground motions,and the results are compared against a baseline model with rigid-elastic connections.The study discusses connection design considerations and evaluates the effectiveness of force-limiting connections in mitigating higher-mode effects.The findings show that force-limiting connections significantly reduce the magnitude and variability of floor accelerations,brace forces,and connection forces,while maintaining comparable story drifts.limiting Force-connections primarily reduce the contribution of higher-mode responses,while the controlled rocking base mechanism modifies the first-mode response.Overall,the reduced dispersion in structural response improves the reliability of seismic design and enhances resilience by minimizing damage to both structural components and acceleration-sensitive nonstructural elements.
文摘The September 2017 earthquakes in Mexico,which struck within a twelve-day span and affected regions with vastly different seismic,socioeconomic,and urban characteristics,revealed the multifactorial nature of seismic vulnerability and resilience in the country.This paper provides a comprehensive review of the damage on the built environment,emergency response,recovery and reconstruction efforts,regulatory evolution,and institu-tional reforms that followed these events.Key topics include the performance of self-built housing and essential infrastructure,the challenges of decentralized building codes and their uneven development and enforcement,the role of civil society,private sector and media in disaster response,and the implementation of the National Reconstruction Program.Advances in seismic code development-particularly the updated Complementary Technical Norms(CTNs)of Mexico City-and the creation of a dedicated standard for the evaluation and rehabilitation of existing buildings are also discussed.The proposed Construction Law for Mexico City,which aims to assign legal responsibility to stakeholders and formalize the regulatory framework,may serve as a legislative model for other regions.The paper concludes by highlighting the importance of coordination,tech-nical rigor,equity and inclusion in recovery and reconstruction,and public engagement in advancing seismic resilience across diverse urban,semi-urban and rural contexts.
文摘Investing in disaster risk reduction is crucial for minimizing the impacts of disasters.However,little is known about the factors that influence changes in investment levels over time.This study aims to identify the key socio-economic drivers behind increases and decreases in flood protection investment in People’s Republic of China(PRC).Such information is crucial for policy makers to justify flood investments.By analyzing data on flood protection expenditures,economic losses from floods,and other relevant indicators from 1980 to 2020,the study evaluates the relationship between investment and disaster impacts through the lens of the flood investment cycle model.It was found that the country succeeded in reducing flood damage because of increasing investment in flood protection.The results indicate that changes in PRC’s flood protection investment have been driven by three major factors:the occurrence of major disasters,the fiscal situation,and shifts in government policies.Investment tended to increase following large-scale events,such as the 1998 Yangtze River Basin flood and the 2008 Wenchuan earthquake,which prompted policy changes and renewed focus on DRR measures.Fiscal constraints limited investment in the 1990s,but reforms and stimulus measures improved the financial situation,enabling increased spending on flood protection.PRC’s experience in steadily reducing flood damage through sustained investment and policy commitment offers valuable lessons for other developing countries facing similar challenges.
文摘Reconstruction of buildings in the Christchurch central business district following the 2011 earthquake has been a massive undertaking that is not yet completed.Interviews have been conducted with representatives of the consulting engineering companies who designed 55 of these buildings from 2017 until 2025 to determine:(i)the building construction materials and structural system types used,and(ii)the drivers for the selection of these systems.The information obtained is compared with a 2017 survey,by the authors,with the same design companies for buildings constructed from 2012 to 2017,as part of the Christchurch rebuild after the 2010-2011 Canterbury earthquakes.It is found that 47%and 45%of the buildings constructed had steel and concrete lateral force resisting systems,respectively,with the remainder using timber.In terms of floor space areas,the steel buildings were typically larger and the ratios were 70%and 24%,respectively.The most popular structural steel seismic systems were MRFs and BRBFs with 29%and 20%of the floor areas,respectively.Gravity systems,when needed,were generally steel.Although slightly different,these numbers are similar in magnitude to those reported in the prior study.However,comparing the factors driving choice of structure systems reported in the previous study,many of the engineers interviewed commented that,as the Canterbury earthquakes became further away in time,fewer of their clients requested resilient designs that would help achieve functionality(e.g.,maintain business continuity)following future earthquakes,requesting instead lowest-cost designs.Nonetheless,it is expected that much of the newer construction will provide improvements in seismic performance given that many buildings were designed for significantly higher strength and lower drift than permitted in the standards.
文摘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.
文摘During the M_(w)=7.1 September 19,2017 earthquake with epicenter nearby the boundary of Puebla and Morelos states,an important amount of structural damage occurred in Mexico City,120 km away from the epicenter.Among the most severely affected sectors was the housing sector.At least 16 houses collapsed or partially collapsed during the earthquake,more than 5100 were demolished with public funds and more than 5800 were sternly damaged and required to be rehabilitated.Close to 1300 apartment buildings were severely damaged,where 33 of them collapsed or partially collapsed.Then,the recovery of the housing sector,which is instrumental for both the social and economy recovery of the city,have posed a monumental task and challenge to the citizens and authorities of Mexico City.In this paper,the author summarizes how these efforts to recover the affected housing sector have been in Mexico City close to eight years after the 9/19/2017 earthquake,based upon detailed statistics and information compiled by the author from different sources.It can be concluded that after 7+years,the recovery process of single-family houses has been a success,as close to 100%of the affected homes have been fully recovered with much better projects than the originally damaged.However,the recovery process of apartment buildings,although important,still has a long way to go.As of May 2025,only 59.6%of the affected buildings have been fully recovered(31.3%using public funds),other 11.3%are under construction or rehabilitation process and,in 29.1%of the affected buildings,no action has been taken to speed their recovery.
文摘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 exam-ining 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 analy-sis 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 con-siderations in the life-cycle design of bridges.
基金funded by the Thailand Science Research and Innovation Fund,Chulalongkorn University(BCG_FF_68_165_2100_027)The first author(Tidarut Jirawattanasomkul)also gratefully acknowledges support from the Grants for Development of New Faculty Staff,Ratchadaphiseksomphot Fund,Chulalongkorn University.The corresponding author(Supasit Srivaranun)acknowledges the Research and Innovation Funding from National Research Council of Thailand(No.N84A680208)+2 种基金the Research Grant from Faculty of Engineering,Kasetsart University(No.67/05/CE)The fourth author(Suched Likitlersuang)acknowledges Thailand Science Research and Innovation Fund Chulalongkorn University(DISF68210001)the National Research Council of Thailand(NRCT):Grant No.N42A670572.
文摘This study developed a digital twin(DT)and structural health monitoring(SHM)system for a balanced cantilever bridge,utilizing advanced measurement techniques to enhance accuracy.Vibration and dynamic strain measurements were obtained using accelerometers and piezo-resistive strain gauges,capturing low-magnitude dynamic strains during operational vibrations.3D-LiDAR scanning and Ultrasonic Pulse Velocity(UPV)tests captured the bridge's as-is geometry and modulus of elasticity.The resulting detailed 3D point cloud model revealed the structure's true state and highlighted discrepancies between the as-designed and as-built conditions.Dynamic properties,including modal frequencies and shapes,were extracted from the strain and acceleration measurements,providing critical insights into the bridge's structural behavior.The neutral axis depth,indicating stress distribution and potential damage,was accurately determined.Good agreement between vibration measurement data and the as-is model results validated the reliability of the digital twin model.Dynamic strain patterns and neutral axis parameters showed strong correlation with model predictions,serving as sensitive indicators of local damage.The baseline digital twin model and measurement results establish a foundation for future bridge inspections and investigations.This study demonstrates the effectiveness of combining digital twin technology with field measurements for real-time monitoring and predictive maintenance,ensuring the sustainability and safety of the bridge infrastructure,thereby enhancing its overall resilience to operational and environmental stressors.
文摘Flooding has become an emerging global catastrophe,generating considerable damage to both infrastructures and lives.Despite the critical need for quantitative assessments of both flood damage and the effectiveness of flood mitigation measures,most existing studies have focused on isolated aspects of flood risk.Only a very limited number of studies have comprehensively integrated hazard mapping,hydrodynamic simulations,and economic damage estimations to evaluate the real-world impact and effectiveness of flood mitigation measures(FMMs).This study presents a multi-method approach to evaluate the performance of such established structural FMMs.Initially,hazard assessments for two selected case study areas,the Colombo Metropolitan Area in Sri Lanka and Auckland,New Zealand,two flood-prone cities with contrasting geographical contexts.Flood inundation mapping for the Madiwela South Diversion,Colombo,Sri Lanka,was performed using hydrodynamic modeling to demonstrate the reduction in flood inundation area and depth after the implementation of the measure,considering six(6)design return periods(RPs).Subsequently,tangible and intangible property damage estimations for“without FMMs”and“with FMMs”were evaluated to identify the benefit of responding to flood conditions,utilising a vulnerability-based economic analysis.In addition to damage estimations,the study adopts a novel approach by conducting an investment viability analysis to find the Benefit-to-Cost ratios and Net Present Value of nine(9)selected FMMs implemented by Sri Lanka Land Development Co-operation(SLLDC).The FMMs implemented by SLLDC were selected from Colombo,Sri Lanka.The quantified damage estimates revealed a reduction in flood damages ranging from 39%to 63%,alongside a decrease in flood inundation depths between 9%and 12%,and the results underscore the significant effectiveness of FMMs in managing urban flooding and minimising its impacts.This cross-disciplinary methodology enables a transferable framework for resilience-oriented urban planning in diverse hydrological and geographical contexts.
基金Financial support for this work was provided by the US Department of Commerce,the National Institute of Standards and Technology(NIST)under the Financial Assistance Award Number#70NANB20H008the US National Science Foundation(NSF)under Award Number 2052930.
文摘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 environ-ment,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.
文摘While in the past the robustness of transportation networks was studied considering the cyber and physical space as isolated environments this is no longer the case.Integrating the Internet of Things devices in the sensing area of transportation infrastructure has resulted in ubiquitous cyber-physical systems and increasing interdependen-cies between the physical and cyber networks.As a result,the robustness of transportation networks relies on the uninterrupted serviceability of physical and cyber networks.Current studies on interdependent networks overlook the civil engineering aspect of cyber-physical systems.Firstly,they rely on the assumption of a uniform and strong level of interdependency.That is,once a node within a network fails its counterpart fails immedi-ately.Current studies overlook the impact of earthquake and other natural hazards on the operation of modern transportation infrastructure,that now serve as a cyber-physical system.The last is responsible not only for the physical operation(e.g.,flow of vehicles)but also for the continuous data transmission and subsequently the cy-ber operation of the entire transportation network.Therefore,the robustness of modern transportation networks should be modelled from a new cyber-physical perspective that includes civil engineering aspects.In this paper,we propose a new robustness assessment approach for modern transportation networks and their underlying in-terdependent physical and cyber network,subjected to earthquake events.The novelty relies on the modelling of interdependent networks,in the form of a graph,based on their interdependency levels.We associate the service-ability level of the coupled physical and cyber network with the damage states induced by earthquake events.Robustness is then measured as a degradation of the cyber-physical serviceability level.The application of the approach is demonstrated by studying an illustrative transportation network using seismic data from real-world transportation infrastructure.Furthermore,we propose the integration of a robustness improvement indicator based on physical and cyber attributes to enhance the cyber-physical serviceability level.Results indicate an improvement in robustness level(i.e.,41%)by adopting the proposed robustness improvement indicator.The usefulness of our approach is highlighted by comparing it with other methods that consider strong interdepen-dencies and key node protection strategies.The approach is of interest to stakeholders who are attempting to incorporate cyber-physical systems into civil engineering systems.
基金funded by the Italian Civil Protection Department and“PriorBuilt-Prioritisation of the Italian regions for seismic and energy performance upgrading of the existing buildings”funded by ReLUIS.Additionally,it was developed as part of the activities of CONSTRUCT–Instituto de I&D em Estruturas e Construções(UID/04708),CERIS(UIDB/04625)+1 种基金the project SERENE(2022.08138.PTDC)all funded by Fundação para a Ciência e a Tecnologia,I.P./MCTES(PIDDAC).
文摘Recent research demonstrates the need for comprehensive frameworks to achieve an appropriate level of resilience(e.g.,energy,seismic)of the European building stock,through integrated retrofitting interventions.Different frameworks have been proposed to identify optimal interventions when several feasible alternatives are available,considering multiple decision variables of different nature,such as social,economic,or technical.Within these efforts and frameworks,less attention has been paid to the post-earthquake recovery time of buildings and communities,thus ignoring the significance of reaching a desired recovery state(e.g.,functional recovery)within a specified time frame.To overcome this limitation,this study estimates post-earthquake recovery times and uses them as one of the decision variables in multi-criteria identification of optimal retrofitting of an existing RC building.The case-study building is representative of the Italian school buildings constructed between the 1960s and 1970s and was analysed under two seismic hazard levels(moderate and high).Following the identification of the main structural deficiencies of the as-built structure through nonlinear static analyses,four seismic retrofit measures were selected.Then,the earthquake-induced downtime of each of the four retrofitted building configurations was assessed,analysing the different recovery times as a function of the seismic hazard level and the recovery state.A downtime-based metric,namely the expected annual downtime,was introduced as decision variable within an available multi-criteria decision-making framework to include the impact of downtime,rank the four retrofit measures and identify the preferable one.
基金financially supported by the National Natural Science Foundation of China(Grants 52178124,52478151).
文摘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.
基金gratitude to WIDE Trust New Zealand for providing the opportunity and funding for this research,as well as QuakeCoRE,a New Zealand Tertiary Education Commission-funded Centre,for partially funding this research.This is QuakeCoRE,publication number 1013.
文摘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.
文摘In the last two decades,seismic resilience(SR)has been developed as a main concept for the assessment of the structural vulnerabilities of buildings and city centres.In particular,historical centers consist of adjacent buildings organized in blocks with common characteristics and similar typologies.The paper proposes a meth-odology to quantify SR for urban regions,by overcoming the state of the art studies that focus on assessing the SR for singular buildings.In this regard,the presented methodology may calculate the SR of blocks of buildings for the assessment of recovery investments of historical city centers.The main idea is to assess the level of vulnerability by accurate 3D surveys and visual inspections in order to select empirical fragility curves.The proposed methodology was herein applied to the city center of San Marino,designated by UNESCO as a world heritage site.
