dina D'Ayala - Profile on Academia.edu (original) (raw)
Papers by dina D'Ayala
Zenodo (CERN European Organization for Nuclear Research), May 28, 2021
This paper presents a method for the development of bridge fragility functions that are able to a... more This paper presents a method for the development of bridge fragility functions that are able to account for the cumulated impact of different hazard types, namely earthquakes, ground failures and fluvial floods. After identifying which loading mechanisms are affecting which bridge components, specific damage-dependent component fragility curves are derived. The definition of the global damage states at system level through a fault-tree analysis is coupled with a Bayesian Network formulation in order to account for the correlation structure between failure events. Fragility functions for four system damage states are finally derived as a function of flow discharge Q (for floods) and peak ground acceleration PGA (for earthquakes and ground failures): the results are able to represent specific failure configurations that can be linked to functionality levels or repair durations.
Natural Hazards and Earth System Sciences, May 5, 2014
The recent increase in frequency and severity of flooding in the UK has led to a shift in the per... more The recent increase in frequency and severity of flooding in the UK has led to a shift in the perception of risk associated with flood hazards. This has extended to the conservation community, and the risks posed to historic structures that suffer from flooding are particularly concerning for those charged with preserving and maintaining such buildings. In order to fully appraise the risks in a manner appropriate to the complex issue of preservation, a new methodology is presented here that studies the nature of the vulnerability of such structures, and places it in the context of risk assessment, accounting for the vulnerable object and the subsequent exposure of that object to flood hazards. The testing of the methodology is carried out using three urban case studies and the results of the survey analysis provide guidance on the development of fragility curves for historic structures exposed to flooding. This occurs through appraisal of vulnerability indicators related to building form, structural and fabric integrity, and preservation of architectural and archaeological values. Key findings of the work include determining the applicability of these indicators to fragility analysis, and the determination of the relative vulnerability of the three case study sites.
Journal of Marine Science and Engineering, Aug 24, 2022
Maintaining offshore steel structures is challenging and not environmentally friendly due to the ... more Maintaining offshore steel structures is challenging and not environmentally friendly due to the frequent visits for inspection and repairs. Some offshore lighthouses are equipped with carbon steel helidecks fixed onto their lantern galleries in the 1970s to provide easy and safe access to maintenance staff and inspectors. Even though the helidecks supporting structures have maintained their integrity and are still functional in the offshore harsh environmental conditions, their inspection and maintenance remains a challenge due to the need of frequent visits which requires flying to the location of the lighthouse to bring the maintenance staff and equipment. We have developed a multidisciplinary computational framework to design new generation of aluminium helidecks for offshore lighthouses. We calculated the wind speed at the location of the Bishop Rock lighthouse based on the meteorological data, and the load distribution on the helideck due to such a wind condition, using computational fluid dynamic analysis. Then, we used the calculated wind load with other mechanical loads in the events of normal and emergency landings of a helicopter on this structure to find the best design configuration for this helideck. We generated a design space for different configurations of a beam structure and carried out, static, transient and buckling analysis to assess each case using finite element method. The selection criterion was set to find the structure with the minimum volume fraction and compliance while keeping the stress below the allowable stress. We found the structure with eight vertical and circumferential sections featuring two rows of diagonal bracing with one at the base and the other one at the third section from the base of the helideck was the optimum design for the considered loading in this work. This framework can be adopted for the design and optimisation of other offshore structures by other researchers and designers.
The recent increase in frequency and severity of flooding in the UK has led to a shift in the per... more The recent increase in frequency and severity of flooding in the UK has led to a shift in the perception of risk associated with flood hazards. This has extended to the conservation community, and the risks posed to historic structures that suffer from flooding are particularly concerning for those charged with preserving and maintaining such buildings. In order to fully appraise the risks in a manner appropriate to the complex issue of preservation, a new methodology is proposed that studies the nature of vulnerability of such structures, and places it in the context of risk assessment, accounting for the vulnerable object and the subsequent exposure of that object to flood hazards. The testing of the methodology is carried out using three urban case studies and the results of the survey analysis provide key findings and guidance on the development of fragility curves for historic structures exposed to flooding. This occurs through appraisal of key vulnerability indicators related to building form, structural and fabric integrity, and preservation of architectural and archaeological values. This in turn facilitates the production of strategies for mitigating and managing the losses threatened by such extreme climate events.
The rate and extent of uptake and release of moisture and liquid water are critical in understand... more The rate and extent of uptake and release of moisture and liquid water are critical in understanding the behaviour of masonry materials. This study focussed on testing brick masonry to identify the moisture performance difference after treated with acrylic based surface waterproofingcommonly used to lessen water uptake and improve façade durability. Brick and mortar specimens were first tested for water absorption then treated and retested 0, 12 and 24 months later to evaluate the short-and long-term impact of waterproofing on their water absorption capacity. Dynamic Vapour Sorption (DVS) tests were also conducted to quantity the change in their (de)sorptive characteristics. Results from both tests were combined to show the impact and durability of acrylic waterproofing on the moisture behaviour of brick masonry. Peer-review under the responsibility of the organizing committee of the ICMB23.
Scientific Reports, Sep 29, 2022
Post-hazard rapid response has emerged as a promising pathway towards resilient critical infrastr... more Post-hazard rapid response has emerged as a promising pathway towards resilient critical infrastructure systems (CISs). Nevertheless, it is challenging to scheme the optimal plan for those rapid responses, given the enormous search space and the hardship of assessment on the spatiotemporal status of CISs. We now present a new approach to post-shock rapid responses of road networks (RNs), based upon lookahead searches supported by machine learning. Following this approach, we examined the resilience-oriented rapid response of a real-world RN across Luchon, France, under destructive earthquake scenarios. Our results show that the introduction of one-step lookahead searches can effectively offset the lack of adaptivity due to the deficient heuristic of rapid responses. Furthermore, the performance of rapid responses following such a strategy is far surpassed, when a series of deep neural networks trained based solely on machine learning, without human interventions, are employed to replace the heuristic and guide the searches.
Buildings, Jan 8, 2023
Masonry buildings are generally vulnerable to seismic action, as evidenced extensively in past ea... more Masonry buildings are generally vulnerable to seismic action, as evidenced extensively in past earthquakes. In order to improve their seismic performance, several modifications have been introduced, such as reinforcing or confining the masonry. This paper presents a seismic analysis and fragility assessment procedure for non-engineered masonry building typologies, employing the applied element method (AEM). Compared to buildings with stiff diaphragms, the conventional pushover-based procedure is challenging for the seismic assessment of masonry buildings with flexible diaphragms, due to the lack of a global box-like behaviour. This study first presents a novel and validated method for nonlinear pushover analysis, independent of the type of diaphragm action on the building, by applying incremental ground acceleration and by considering suitable engineering demand parameters for the assessment of lateral capacity. Based on the failure mechanisms, a seismic performance assessment and fragility evaluation approach is then proposed, for reliable accounting of both the in-plane and out-of-plane failure modes. Finally, the proposed methodology is applied to a number of unreinforced and confined masonry school buildings with different seismic detailing levels, as often found in the Himalayan belt and beyond.
Philosophical Transactions of the Royal Society A, Aug 19, 2019
Lighthouses situated on exposed rocky outcrops warn mariners of the dangers that lurk beneath the... more Lighthouses situated on exposed rocky outcrops warn mariners of the dangers that lurk beneath the waves. They were first constructed when approaches to wave loading and structural response were relatively unsophisticated, essentially learning from previous failures. Here, we chart the evolution of lighthouses on the Wolf Rock, situated between Land's End and the Isles of Scilly in the UK. The first empirical approaches are described, followed by design aspects of the present tower, informed by innovations developed on other rocky outcrops. We focus on a particular development associated with the automation of lighthouses: the helideck platform. The design concept is described and the structure then scrutinized for future survivability, using the latest structural modelling techniques of the entire lighthouse and helideck. Model validation data were obtained through a complex logistical field operation and experimental modal analysis. Extreme wave
Zenodo (CERN European Organization for Nuclear Research), Nov 27, 2020
WIT Transactions on the Built Environment, 1970
Using statistical tools, an extensive review of the experimental literature on historic masonry h... more Using statistical tools, an extensive review of the experimental literature on historic masonry has been carried out and a database obtained. From the statistical analysis of the data the correlation between a range of parameters emerged and regression's curves have been derived, which enable definition of the mechanic features of the masonry, when some of the mechanics and geometric feature of the components are known. The application to a number of f.e. non-linear models of simple structures is discussed. The procedure obtained can be a valid alternative to destructive tests on masonry buildings of historical or monumental value.
Scientific Reports, May 17, 2022
When a seismic event occurs, transportation networks play a critical role in undertaking emergenc... more When a seismic event occurs, transportation networks play a critical role in undertaking emergency activities such as evacuation and relief supply. Accordingly, to secure their functionality, it is essential to accurately assess their resilience. In particular, this study performs a rigorous probabilistic analysis on the seismic resilience of a transportation network in Istanbul, Turkey. The analysis accuracy is enhanced by considering, along with the structural damage of roadways, the additional disruption mode of network performance caused by the debris falling from damaged objects in their vicinity. Moreover, we obtain the results as a map of resilience measure, which enables us to investigate the disruption inequality across the study area and identify critical factors that govern the system resilience. To enable such sophisticated probabilistic analysis, a Bayesian network (BN) model is developed that involves various types of information from the hazard process to the performance of structures and systems. Then, the BN is quantified by identifying and compiling a comprehensive list of datasets. Thereby, this study analyses large-scale systems involving thousands of structures, while providing general probabilistic models and data schema that can be employed for other transportation networks. Transportation networks play a critical role in maintaining welfare and economic systems of modern societies 1 . Their role becomes even more critical when facing disruptive events such as earthquakes, as they are essential to enable emergency activities, evacuation and relief supply and to expedite restorations to normality. The breakdown of these systems under a seismic event can bring about devastating consequences, as witnessed, for instance, in the 2016 Kaikoura, New Zealand earthquake 2 . To prevent such disastrous outcomes, it is essential to accurately evaluate the disaster resilience of those systems. However, such analysis remains challenging as it involves diverse sets of variables interacting to each other (e.g. hazard processes, structural damages and recovery works), a particularly critical issue for large-scale transportation networks with many roadways, such as metropolitan neighbourhoods. Since a resilience analysis requires a modelling and evaluation of the complex dependency between those variables, challenges arise from both compiling all relevant data and computing complex models. Moreover, while the primary disruption would be caused by the structural damage of roadways, further disruptions can occur as the debris generated from the adjacent objects (e.g. buildings, overpasses and slopes) falls onto the roadways . Such additional disruption mode heightens the aforementioned challenges, i.e. data compilation and correlation/computational scale. These disruptions may have a significant influence on analysis results, especially for urban transportation networks which are often set within dense built up areas. While this issue has been investigated at the level of individual roadways , this is an area of emerging study currently hindered by limited research and data. Still, considering the continuing expansion of urban areas, the analysis model needs to take into account both disruption modes, so that the analysis accuracy can be enhanced, and the interactions across multiple contributing factors can be better understood. To evaluate system resilience, an essential prerequisite is to define a measure of system functionality. While it can be defined either at component-level or at system-level, the latter definition enables us to consider the interdependency between the operation of roadways and thereby, to reflect the reality more accurately. However, such system-level approach is more challenging as the associated network analysis in general demands more detailed data and higher computational cost. Moreover, since the objective of resilience analysis is to enable riskinformed decision-making, it is critical to establish resilience metrics that effectively serve decision objectives of interest and communicate loss and recovery in operational terms. This study aims to address the inequality in the accessibility of infrastructure, following a seismic event. While it has been actively investigated for transportation
Bulletin of Earthquake Engineering
The assessment of the seismic behaviour of historic residential buildings and the estimation of t... more The assessment of the seismic behaviour of historic residential buildings and the estimation of their possible losses in the event of an earthquake, is a must for defining strategic mitigation plans to prevent irreplaceable heritage losses. In this study an integrated performance based probabilistic risk assessment methodology is developed. An archival study and a field survey allow to identify architectural and construction characteristics of heritage residential buildings in urban areas and determine realistic structural models. These are analysed by using a limit state approach, coded in the FaMIVE method, considering different construction hypotheses, to produce capacity curves which support the identification of a discrete number of typologies representative of the entire building stock in the area. Their fragility functions are then derived using the modified N2 method. Because of the difficulty in quantifying the expected probable losses in purely economic terms, given the he...
Zenodo (CERN European Organization for Nuclear Research), Dec 15, 2022
HAL (Le Centre pour la Communication Scientifique Directe), Sep 4, 2022
Within moments following an earthquake event, observations collected from the affected area can b... more Within moments following an earthquake event, observations collected from the affected area can be used to define a picture of expected losses and to provide emergency services with accurate information. A Bayesian Network framework could be used to update the prior loss estimates based on ground-motion prediction equations and fragility curves, considering various field observations (i.e., evidence). The present study explores the applicability of approximate Bayesian inference, based on Monte-Carlo Markov-Chain sampling algorithms, to a real-world network of roads where expected loss metrics pertain to the accessibility between damaged areas and hospitals in the region. Observations are gathered either from free-field stations (for updating the ground-motion field) or from structure-mounted stations (for the updating of the damage states of infrastructure components). It is found that the proposed Bayesian approach is able to process a system comprising hundreds of components with reasonable accuracy, time and computation cost. Emergency managers may readily use the updated loss distributions to make informed decisions.
Zenodo (CERN European Organization for Nuclear Research), Aug 3, 2022
Zenodo (CERN European Organization for Nuclear Research), May 28, 2021
This paper presents a method for the development of bridge fragility functions that are able to a... more This paper presents a method for the development of bridge fragility functions that are able to account for the cumulated impact of different hazard types, namely earthquakes, ground failures and fluvial floods. After identifying which loading mechanisms are affecting which bridge components, specific damage-dependent component fragility curves are derived. The definition of the global damage states at system level through a fault-tree analysis is coupled with a Bayesian Network formulation in order to account for the correlation structure between failure events. Fragility functions for four system damage states are finally derived as a function of flow discharge Q (for floods) and peak ground acceleration PGA (for earthquakes and ground failures): the results are able to represent specific failure configurations that can be linked to functionality levels or repair durations.
Natural Hazards and Earth System Sciences, May 5, 2014
The recent increase in frequency and severity of flooding in the UK has led to a shift in the per... more The recent increase in frequency and severity of flooding in the UK has led to a shift in the perception of risk associated with flood hazards. This has extended to the conservation community, and the risks posed to historic structures that suffer from flooding are particularly concerning for those charged with preserving and maintaining such buildings. In order to fully appraise the risks in a manner appropriate to the complex issue of preservation, a new methodology is presented here that studies the nature of the vulnerability of such structures, and places it in the context of risk assessment, accounting for the vulnerable object and the subsequent exposure of that object to flood hazards. The testing of the methodology is carried out using three urban case studies and the results of the survey analysis provide guidance on the development of fragility curves for historic structures exposed to flooding. This occurs through appraisal of vulnerability indicators related to building form, structural and fabric integrity, and preservation of architectural and archaeological values. Key findings of the work include determining the applicability of these indicators to fragility analysis, and the determination of the relative vulnerability of the three case study sites.
Journal of Marine Science and Engineering, Aug 24, 2022
Maintaining offshore steel structures is challenging and not environmentally friendly due to the ... more Maintaining offshore steel structures is challenging and not environmentally friendly due to the frequent visits for inspection and repairs. Some offshore lighthouses are equipped with carbon steel helidecks fixed onto their lantern galleries in the 1970s to provide easy and safe access to maintenance staff and inspectors. Even though the helidecks supporting structures have maintained their integrity and are still functional in the offshore harsh environmental conditions, their inspection and maintenance remains a challenge due to the need of frequent visits which requires flying to the location of the lighthouse to bring the maintenance staff and equipment. We have developed a multidisciplinary computational framework to design new generation of aluminium helidecks for offshore lighthouses. We calculated the wind speed at the location of the Bishop Rock lighthouse based on the meteorological data, and the load distribution on the helideck due to such a wind condition, using computational fluid dynamic analysis. Then, we used the calculated wind load with other mechanical loads in the events of normal and emergency landings of a helicopter on this structure to find the best design configuration for this helideck. We generated a design space for different configurations of a beam structure and carried out, static, transient and buckling analysis to assess each case using finite element method. The selection criterion was set to find the structure with the minimum volume fraction and compliance while keeping the stress below the allowable stress. We found the structure with eight vertical and circumferential sections featuring two rows of diagonal bracing with one at the base and the other one at the third section from the base of the helideck was the optimum design for the considered loading in this work. This framework can be adopted for the design and optimisation of other offshore structures by other researchers and designers.
The recent increase in frequency and severity of flooding in the UK has led to a shift in the per... more The recent increase in frequency and severity of flooding in the UK has led to a shift in the perception of risk associated with flood hazards. This has extended to the conservation community, and the risks posed to historic structures that suffer from flooding are particularly concerning for those charged with preserving and maintaining such buildings. In order to fully appraise the risks in a manner appropriate to the complex issue of preservation, a new methodology is proposed that studies the nature of vulnerability of such structures, and places it in the context of risk assessment, accounting for the vulnerable object and the subsequent exposure of that object to flood hazards. The testing of the methodology is carried out using three urban case studies and the results of the survey analysis provide key findings and guidance on the development of fragility curves for historic structures exposed to flooding. This occurs through appraisal of key vulnerability indicators related to building form, structural and fabric integrity, and preservation of architectural and archaeological values. This in turn facilitates the production of strategies for mitigating and managing the losses threatened by such extreme climate events.
The rate and extent of uptake and release of moisture and liquid water are critical in understand... more The rate and extent of uptake and release of moisture and liquid water are critical in understanding the behaviour of masonry materials. This study focussed on testing brick masonry to identify the moisture performance difference after treated with acrylic based surface waterproofingcommonly used to lessen water uptake and improve façade durability. Brick and mortar specimens were first tested for water absorption then treated and retested 0, 12 and 24 months later to evaluate the short-and long-term impact of waterproofing on their water absorption capacity. Dynamic Vapour Sorption (DVS) tests were also conducted to quantity the change in their (de)sorptive characteristics. Results from both tests were combined to show the impact and durability of acrylic waterproofing on the moisture behaviour of brick masonry. Peer-review under the responsibility of the organizing committee of the ICMB23.
Scientific Reports, Sep 29, 2022
Post-hazard rapid response has emerged as a promising pathway towards resilient critical infrastr... more Post-hazard rapid response has emerged as a promising pathway towards resilient critical infrastructure systems (CISs). Nevertheless, it is challenging to scheme the optimal plan for those rapid responses, given the enormous search space and the hardship of assessment on the spatiotemporal status of CISs. We now present a new approach to post-shock rapid responses of road networks (RNs), based upon lookahead searches supported by machine learning. Following this approach, we examined the resilience-oriented rapid response of a real-world RN across Luchon, France, under destructive earthquake scenarios. Our results show that the introduction of one-step lookahead searches can effectively offset the lack of adaptivity due to the deficient heuristic of rapid responses. Furthermore, the performance of rapid responses following such a strategy is far surpassed, when a series of deep neural networks trained based solely on machine learning, without human interventions, are employed to replace the heuristic and guide the searches.
Buildings, Jan 8, 2023
Masonry buildings are generally vulnerable to seismic action, as evidenced extensively in past ea... more Masonry buildings are generally vulnerable to seismic action, as evidenced extensively in past earthquakes. In order to improve their seismic performance, several modifications have been introduced, such as reinforcing or confining the masonry. This paper presents a seismic analysis and fragility assessment procedure for non-engineered masonry building typologies, employing the applied element method (AEM). Compared to buildings with stiff diaphragms, the conventional pushover-based procedure is challenging for the seismic assessment of masonry buildings with flexible diaphragms, due to the lack of a global box-like behaviour. This study first presents a novel and validated method for nonlinear pushover analysis, independent of the type of diaphragm action on the building, by applying incremental ground acceleration and by considering suitable engineering demand parameters for the assessment of lateral capacity. Based on the failure mechanisms, a seismic performance assessment and fragility evaluation approach is then proposed, for reliable accounting of both the in-plane and out-of-plane failure modes. Finally, the proposed methodology is applied to a number of unreinforced and confined masonry school buildings with different seismic detailing levels, as often found in the Himalayan belt and beyond.
Philosophical Transactions of the Royal Society A, Aug 19, 2019
Lighthouses situated on exposed rocky outcrops warn mariners of the dangers that lurk beneath the... more Lighthouses situated on exposed rocky outcrops warn mariners of the dangers that lurk beneath the waves. They were first constructed when approaches to wave loading and structural response were relatively unsophisticated, essentially learning from previous failures. Here, we chart the evolution of lighthouses on the Wolf Rock, situated between Land's End and the Isles of Scilly in the UK. The first empirical approaches are described, followed by design aspects of the present tower, informed by innovations developed on other rocky outcrops. We focus on a particular development associated with the automation of lighthouses: the helideck platform. The design concept is described and the structure then scrutinized for future survivability, using the latest structural modelling techniques of the entire lighthouse and helideck. Model validation data were obtained through a complex logistical field operation and experimental modal analysis. Extreme wave
Zenodo (CERN European Organization for Nuclear Research), Nov 27, 2020
WIT Transactions on the Built Environment, 1970
Using statistical tools, an extensive review of the experimental literature on historic masonry h... more Using statistical tools, an extensive review of the experimental literature on historic masonry has been carried out and a database obtained. From the statistical analysis of the data the correlation between a range of parameters emerged and regression's curves have been derived, which enable definition of the mechanic features of the masonry, when some of the mechanics and geometric feature of the components are known. The application to a number of f.e. non-linear models of simple structures is discussed. The procedure obtained can be a valid alternative to destructive tests on masonry buildings of historical or monumental value.
Scientific Reports, May 17, 2022
When a seismic event occurs, transportation networks play a critical role in undertaking emergenc... more When a seismic event occurs, transportation networks play a critical role in undertaking emergency activities such as evacuation and relief supply. Accordingly, to secure their functionality, it is essential to accurately assess their resilience. In particular, this study performs a rigorous probabilistic analysis on the seismic resilience of a transportation network in Istanbul, Turkey. The analysis accuracy is enhanced by considering, along with the structural damage of roadways, the additional disruption mode of network performance caused by the debris falling from damaged objects in their vicinity. Moreover, we obtain the results as a map of resilience measure, which enables us to investigate the disruption inequality across the study area and identify critical factors that govern the system resilience. To enable such sophisticated probabilistic analysis, a Bayesian network (BN) model is developed that involves various types of information from the hazard process to the performance of structures and systems. Then, the BN is quantified by identifying and compiling a comprehensive list of datasets. Thereby, this study analyses large-scale systems involving thousands of structures, while providing general probabilistic models and data schema that can be employed for other transportation networks. Transportation networks play a critical role in maintaining welfare and economic systems of modern societies 1 . Their role becomes even more critical when facing disruptive events such as earthquakes, as they are essential to enable emergency activities, evacuation and relief supply and to expedite restorations to normality. The breakdown of these systems under a seismic event can bring about devastating consequences, as witnessed, for instance, in the 2016 Kaikoura, New Zealand earthquake 2 . To prevent such disastrous outcomes, it is essential to accurately evaluate the disaster resilience of those systems. However, such analysis remains challenging as it involves diverse sets of variables interacting to each other (e.g. hazard processes, structural damages and recovery works), a particularly critical issue for large-scale transportation networks with many roadways, such as metropolitan neighbourhoods. Since a resilience analysis requires a modelling and evaluation of the complex dependency between those variables, challenges arise from both compiling all relevant data and computing complex models. Moreover, while the primary disruption would be caused by the structural damage of roadways, further disruptions can occur as the debris generated from the adjacent objects (e.g. buildings, overpasses and slopes) falls onto the roadways . Such additional disruption mode heightens the aforementioned challenges, i.e. data compilation and correlation/computational scale. These disruptions may have a significant influence on analysis results, especially for urban transportation networks which are often set within dense built up areas. While this issue has been investigated at the level of individual roadways , this is an area of emerging study currently hindered by limited research and data. Still, considering the continuing expansion of urban areas, the analysis model needs to take into account both disruption modes, so that the analysis accuracy can be enhanced, and the interactions across multiple contributing factors can be better understood. To evaluate system resilience, an essential prerequisite is to define a measure of system functionality. While it can be defined either at component-level or at system-level, the latter definition enables us to consider the interdependency between the operation of roadways and thereby, to reflect the reality more accurately. However, such system-level approach is more challenging as the associated network analysis in general demands more detailed data and higher computational cost. Moreover, since the objective of resilience analysis is to enable riskinformed decision-making, it is critical to establish resilience metrics that effectively serve decision objectives of interest and communicate loss and recovery in operational terms. This study aims to address the inequality in the accessibility of infrastructure, following a seismic event. While it has been actively investigated for transportation
Bulletin of Earthquake Engineering
The assessment of the seismic behaviour of historic residential buildings and the estimation of t... more The assessment of the seismic behaviour of historic residential buildings and the estimation of their possible losses in the event of an earthquake, is a must for defining strategic mitigation plans to prevent irreplaceable heritage losses. In this study an integrated performance based probabilistic risk assessment methodology is developed. An archival study and a field survey allow to identify architectural and construction characteristics of heritage residential buildings in urban areas and determine realistic structural models. These are analysed by using a limit state approach, coded in the FaMIVE method, considering different construction hypotheses, to produce capacity curves which support the identification of a discrete number of typologies representative of the entire building stock in the area. Their fragility functions are then derived using the modified N2 method. Because of the difficulty in quantifying the expected probable losses in purely economic terms, given the he...
Zenodo (CERN European Organization for Nuclear Research), Dec 15, 2022
HAL (Le Centre pour la Communication Scientifique Directe), Sep 4, 2022
Within moments following an earthquake event, observations collected from the affected area can b... more Within moments following an earthquake event, observations collected from the affected area can be used to define a picture of expected losses and to provide emergency services with accurate information. A Bayesian Network framework could be used to update the prior loss estimates based on ground-motion prediction equations and fragility curves, considering various field observations (i.e., evidence). The present study explores the applicability of approximate Bayesian inference, based on Monte-Carlo Markov-Chain sampling algorithms, to a real-world network of roads where expected loss metrics pertain to the accessibility between damaged areas and hospitals in the region. Observations are gathered either from free-field stations (for updating the ground-motion field) or from structure-mounted stations (for the updating of the damage states of infrastructure components). It is found that the proposed Bayesian approach is able to process a system comprising hundreds of components with reasonable accuracy, time and computation cost. Emergency managers may readily use the updated loss distributions to make informed decisions.
Zenodo (CERN European Organization for Nuclear Research), Aug 3, 2022