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Papers by Alessandra De Angelis
Sustainability, 2021
The increasing attention paid to climate change has boosted scientific research in the matter of ... more The increasing attention paid to climate change has boosted scientific research in the matter of energy refurbishment of existing public buildings. However, the design of the intervention must be integrated with structural upgrading when the constructions are located in seismic zones. Indeed, in Italy, as in other seismically active countries, the structural damage, observed after earthquakes, underlines the increase in economic losses for buildings retrofitted only for energy saving. In this framework, the paper introduces an integrated approach for selecting retrofit actions aimed at improving both the seismic and energy performance, starting from a detailed in situ analysis with which dynamic energy and structural simulation models are constructed. The case study is an auditorium erected in 1982 with a reinforced concrete structure inside a masonry ring wall of an ancient building. A step-by-step analysis of each component role in the structural and energy performance of the buil...
Lecture Notes in Civil Engineering, 2021
Masonry heritage structures are among the most vulnerable typologies during earthquake. Their saf... more Masonry heritage structures are among the most vulnerable typologies during earthquake. Their safety assessment requires a higher degree of accuracy due to the lack of knowledge on the original design and the construction procedures. The collection of information about the hidden geometry and the material properties should be performed by non-destructive techniques to avoid any damage to the artistic value. Moreover, for the assessment of the structural behavior a reliable method is the structural identification by on-site dynamic test. In this paper the results of the ambient vibration test and operational modal analysis are reported to calibrate a FE model of the historical masonry bell-tower of S. Sofia. The bell tower of S. Sofia is part of the monumental complex of S. Sofia, in Benevento together with the S. Sofia church, the monastery and the fountain. In 2011, this monumental complex was added in the World Heritage List of UNESCO. The bell tower is about 26 m high and it is c...
Lecture Notes in Civil Engineering, 2021
Field observations after seismic events evidenced that out-of-plane collapse can be one of the pr... more Field observations after seismic events evidenced that out-of-plane collapse can be one of the predominant mode of infill failure leading to life-safety hazard. This type of mechanism depends on the geometrical and mechanical features of the wall but it is substantially affected by the constraints along the structural frame; however, these actual boundary conditions are very difficult to be defined, especially in the case of an existing building, for which information are lack, a visual screening can be inefficient, and deterioration can be occurred respect to the design conditions. In this paper a procedure for the structural identification of the out-of-plane behaviour of infill walls using a simple and cost effective innovative procedure based on in situ experimental dynamic test and a consequent process of updating is proposed. The procedure, composed of the in-situ test and the updating of the numerical model, was implemented for a case study confirming it is effective in defin...
8th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering Methods in Structural Dynamics and Earthquake Engineering
8th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering Methods in Structural Dynamics and Earthquake Engineering
Frontiers in Built Environment
Masonry infill walls are commonly used in the frames of reinforced concrete (RC) buildings around... more Masonry infill walls are commonly used in the frames of reinforced concrete (RC) buildings around the world. The seismic performance of these buildings is strongly affected by the presence of the infill walls and partitions, as shown by the post-earthquake damage in many cases. The effect of these components is particularly important for RC frame constructions underdesigned for seismic actions that usually are characterized by deformable frames magnifying the contribution of the infill walls to the seismic response. Also the flexibility of the floors could be influenced by the collaboration of the infill walls to the transversal stiffness of the building. The paper addresses the seismic assessment of a typical infilled RC frame building designed only for gravity loads in the 1960s in the Southern of Italy that currently is a high-seismic zone. The structural identification of the building based on ambient vibration test has been already done pointing out the significant role of infi...
Buildings
The paper introduces a new semi-probabilistic methodology for the definition of energy fragility ... more The paper introduces a new semi-probabilistic methodology for the definition of energy fragility curves suitable for a macro-classification of building stock inspired to and coupled with the widely adopted method of seismic fragility curves. The approach is applied to the reinforced concrete residential buildings of the Italian stock. Starting from a classification according to the climatic zone and the construction period, some reference buildings in terms of building envelope typologies have been defined and simulated by means of dynamic modeling tools. Then, cumulative distributions of the probability that the primary energy consumption for heating was comparable with certain threshold values are defined according to the climatic conditions expressed with the heating degree days, which constitute the intensity measure for the fragility curves. Finally, by focusing on the interaction points between structural and energetic aspects, it is shown how these curves can be useful for de...
Infrastructures
Recent seismic events that hit the central part of Italy have highlighted again the high vulnerab... more Recent seismic events that hit the central part of Italy have highlighted again the high vulnerability of the historical and architectonical heritage of Italy and the importance of preserving it. However, the seismic assessment of monumental buildings is particularly complex because each historical construction is a singular case realized by specific techniques. Therefore, the first step should be the knowledge of the building even if it is a difficult task. In the present paper, the seismic behavior of an important nineteenth century astronomical observatory, constructed between 1816 and 1819, was investigated. The building, located in Naples, in the southern part of Italy, and classified by the Italian code as an area of medium seismic hazard, was analyzed in the elastic and inelastic range under seismic actions. In this study, the results of two different models were proposed and critically compared. The first one was implemented by shell elements for walls and vaults developing ...
Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015), 2019
Structural Control and Health Monitoring
Journal of Civil Structural Health Monitoring
Engineering Structures
Abstract Field observations after seismic events have shown that out-of-plane collapses are one o... more Abstract Field observations after seismic events have shown that out-of-plane collapses are one of the predominant modes of infill masonry wall failure leading to life-safety hazards. This type of mechanism depends on the geometrical and mechanical features of the structure, but it is substantially affected by the constraints along the structural frame. However, the actual boundary conditions are very difficult to define, especially in the case of an existing building, for which information is lacking, a visual screening can be inefficient, and deterioration may have occurred due to the design conditions. In this paper, a procedure for the structural identification of the out-of-plane behaviour of infill masonry walls using a simple and cost effective innovative procedure based on an in situ experimental dynamic test and a consequent process of updating is proposed. The procedure, composed of the in situ test and the updating of the numerical model, was implemented for a case study to confirm that it is effective in defining the mechanical characteristics of the masonry, the absence of collaboration between the two brick leaves of the infill wall, and the out-of-plane constraints along the perimeter.
Journal of Bridge Engineering
Applied Mechanics and Materials, 2016
The paper analyses the effect of Soil-Structure-Interaction (SSI) on the modal dynamic response o... more The paper analyses the effect of Soil-Structure-Interaction (SSI) on the modal dynamic response of simply-supported span girder bridge with wall piers founded on caissons. A parametric analysis has been carried out in the hypothesis of linear elastic behaviour of all materials (soil and structure) to identify the influence of various design factors, such as the height of the pier, the caisson embedment below the ground level and the soil mechanical properties. The goal of the paper is to highlight SSI effects on the dynamic behaviour of bridges. This is a crucial aspect to be accounted for in order to support monitoring activities on bridges, aimed to structural identification or assessment of structure response under serviceability conditions, or also to have preliminary information for the seismic analysis of the bridge.
Natural Hazards, 2015
This paper addresses the large-scale classification of the seismic vulnerability of nonstructural... more This paper addresses the large-scale classification of the seismic vulnerability of nonstructural components in school buildings. A rapid visual screening methodology is proposed that highlights the factors that likely have a major effect on the seismic behavior of nonstructural building components. This methodology is based primarily on questionnaire forms that are used to construct a nonstructural index and priority ranking that identifies the most vulnerable category of nonstructural components. Because numerical answers in the questionnaires can produce unreliable results, a calibration of the categories by weight is proposed via fragility functions to obtain a vulnerability index. Finally, the developed methodology is applied to a case study of school buildings in Italy.
Bulletin of Earthquake Engineering, 2015
Engineering Structures, 2014
ABSTRACT Reinforced Concrete (RC) walls are defined as large lightly reinforced walls if they are... more ABSTRACT Reinforced Concrete (RC) walls are defined as large lightly reinforced walls if they are not provided of high reinforcement percentage or if they are lack of reinforcement details usually required to improve the ductility of the structure. This type of walls gained relevance in 1950s–1970s constructions because of their good performances under seismic actions. Real earthquakes have, indeed, demonstrated that buildings constructed with large lightly reinforced walls, characterised by adequate area respect to the floor extension, could suffer lower damages in comparison with traditional RC framed buildings. Moreover, a widespread use of such a construction typology is outstanding thanks to the diffusion on the market of new types of integrated formworks, including insulating materials such as polystyrene, that are being used for casting concrete and are aimed to obtain a higher energetic efficiency and build structures made of continuous lightly reinforced walls. Nevertheless, there is a lack of both experimental information and specific design indications in technical codes on this type of construction. This paper firstly reviews the European code requirements for large lightly reinforced walls. Then, some experimental tests on RC walls in the existing literature are studied in detail also by means of a nonlinear Finite Element (FE) model. Finally, the performances of a whole RC building designed with both large lightly reinforced walls along the perimeter and internal frames have been also exploited by linear dynamic and static nonlinear analysis. The analysis are mainly aimed to highlight the influence of in-plane stiffness of the floor on the dynamic behaviour of the structure and to assess the contribution of both ductility and over-strength to the behaviour factor, i.e. to the seismic performance of such type of buildings, considering the lack of information in the technical literature about these features.
Sustainability, 2021
The increasing attention paid to climate change has boosted scientific research in the matter of ... more The increasing attention paid to climate change has boosted scientific research in the matter of energy refurbishment of existing public buildings. However, the design of the intervention must be integrated with structural upgrading when the constructions are located in seismic zones. Indeed, in Italy, as in other seismically active countries, the structural damage, observed after earthquakes, underlines the increase in economic losses for buildings retrofitted only for energy saving. In this framework, the paper introduces an integrated approach for selecting retrofit actions aimed at improving both the seismic and energy performance, starting from a detailed in situ analysis with which dynamic energy and structural simulation models are constructed. The case study is an auditorium erected in 1982 with a reinforced concrete structure inside a masonry ring wall of an ancient building. A step-by-step analysis of each component role in the structural and energy performance of the buil...
Lecture Notes in Civil Engineering, 2021
Masonry heritage structures are among the most vulnerable typologies during earthquake. Their saf... more Masonry heritage structures are among the most vulnerable typologies during earthquake. Their safety assessment requires a higher degree of accuracy due to the lack of knowledge on the original design and the construction procedures. The collection of information about the hidden geometry and the material properties should be performed by non-destructive techniques to avoid any damage to the artistic value. Moreover, for the assessment of the structural behavior a reliable method is the structural identification by on-site dynamic test. In this paper the results of the ambient vibration test and operational modal analysis are reported to calibrate a FE model of the historical masonry bell-tower of S. Sofia. The bell tower of S. Sofia is part of the monumental complex of S. Sofia, in Benevento together with the S. Sofia church, the monastery and the fountain. In 2011, this monumental complex was added in the World Heritage List of UNESCO. The bell tower is about 26 m high and it is c...
Lecture Notes in Civil Engineering, 2021
Field observations after seismic events evidenced that out-of-plane collapse can be one of the pr... more Field observations after seismic events evidenced that out-of-plane collapse can be one of the predominant mode of infill failure leading to life-safety hazard. This type of mechanism depends on the geometrical and mechanical features of the wall but it is substantially affected by the constraints along the structural frame; however, these actual boundary conditions are very difficult to be defined, especially in the case of an existing building, for which information are lack, a visual screening can be inefficient, and deterioration can be occurred respect to the design conditions. In this paper a procedure for the structural identification of the out-of-plane behaviour of infill walls using a simple and cost effective innovative procedure based on in situ experimental dynamic test and a consequent process of updating is proposed. The procedure, composed of the in-situ test and the updating of the numerical model, was implemented for a case study confirming it is effective in defin...
8th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering Methods in Structural Dynamics and Earthquake Engineering
8th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering Methods in Structural Dynamics and Earthquake Engineering
Frontiers in Built Environment
Masonry infill walls are commonly used in the frames of reinforced concrete (RC) buildings around... more Masonry infill walls are commonly used in the frames of reinforced concrete (RC) buildings around the world. The seismic performance of these buildings is strongly affected by the presence of the infill walls and partitions, as shown by the post-earthquake damage in many cases. The effect of these components is particularly important for RC frame constructions underdesigned for seismic actions that usually are characterized by deformable frames magnifying the contribution of the infill walls to the seismic response. Also the flexibility of the floors could be influenced by the collaboration of the infill walls to the transversal stiffness of the building. The paper addresses the seismic assessment of a typical infilled RC frame building designed only for gravity loads in the 1960s in the Southern of Italy that currently is a high-seismic zone. The structural identification of the building based on ambient vibration test has been already done pointing out the significant role of infi...
Buildings
The paper introduces a new semi-probabilistic methodology for the definition of energy fragility ... more The paper introduces a new semi-probabilistic methodology for the definition of energy fragility curves suitable for a macro-classification of building stock inspired to and coupled with the widely adopted method of seismic fragility curves. The approach is applied to the reinforced concrete residential buildings of the Italian stock. Starting from a classification according to the climatic zone and the construction period, some reference buildings in terms of building envelope typologies have been defined and simulated by means of dynamic modeling tools. Then, cumulative distributions of the probability that the primary energy consumption for heating was comparable with certain threshold values are defined according to the climatic conditions expressed with the heating degree days, which constitute the intensity measure for the fragility curves. Finally, by focusing on the interaction points between structural and energetic aspects, it is shown how these curves can be useful for de...
Infrastructures
Recent seismic events that hit the central part of Italy have highlighted again the high vulnerab... more Recent seismic events that hit the central part of Italy have highlighted again the high vulnerability of the historical and architectonical heritage of Italy and the importance of preserving it. However, the seismic assessment of monumental buildings is particularly complex because each historical construction is a singular case realized by specific techniques. Therefore, the first step should be the knowledge of the building even if it is a difficult task. In the present paper, the seismic behavior of an important nineteenth century astronomical observatory, constructed between 1816 and 1819, was investigated. The building, located in Naples, in the southern part of Italy, and classified by the Italian code as an area of medium seismic hazard, was analyzed in the elastic and inelastic range under seismic actions. In this study, the results of two different models were proposed and critically compared. The first one was implemented by shell elements for walls and vaults developing ...
Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015), 2019
Structural Control and Health Monitoring
Journal of Civil Structural Health Monitoring
Engineering Structures
Abstract Field observations after seismic events have shown that out-of-plane collapses are one o... more Abstract Field observations after seismic events have shown that out-of-plane collapses are one of the predominant modes of infill masonry wall failure leading to life-safety hazards. This type of mechanism depends on the geometrical and mechanical features of the structure, but it is substantially affected by the constraints along the structural frame. However, the actual boundary conditions are very difficult to define, especially in the case of an existing building, for which information is lacking, a visual screening can be inefficient, and deterioration may have occurred due to the design conditions. In this paper, a procedure for the structural identification of the out-of-plane behaviour of infill masonry walls using a simple and cost effective innovative procedure based on an in situ experimental dynamic test and a consequent process of updating is proposed. The procedure, composed of the in situ test and the updating of the numerical model, was implemented for a case study to confirm that it is effective in defining the mechanical characteristics of the masonry, the absence of collaboration between the two brick leaves of the infill wall, and the out-of-plane constraints along the perimeter.
Journal of Bridge Engineering
Applied Mechanics and Materials, 2016
The paper analyses the effect of Soil-Structure-Interaction (SSI) on the modal dynamic response o... more The paper analyses the effect of Soil-Structure-Interaction (SSI) on the modal dynamic response of simply-supported span girder bridge with wall piers founded on caissons. A parametric analysis has been carried out in the hypothesis of linear elastic behaviour of all materials (soil and structure) to identify the influence of various design factors, such as the height of the pier, the caisson embedment below the ground level and the soil mechanical properties. The goal of the paper is to highlight SSI effects on the dynamic behaviour of bridges. This is a crucial aspect to be accounted for in order to support monitoring activities on bridges, aimed to structural identification or assessment of structure response under serviceability conditions, or also to have preliminary information for the seismic analysis of the bridge.
Natural Hazards, 2015
This paper addresses the large-scale classification of the seismic vulnerability of nonstructural... more This paper addresses the large-scale classification of the seismic vulnerability of nonstructural components in school buildings. A rapid visual screening methodology is proposed that highlights the factors that likely have a major effect on the seismic behavior of nonstructural building components. This methodology is based primarily on questionnaire forms that are used to construct a nonstructural index and priority ranking that identifies the most vulnerable category of nonstructural components. Because numerical answers in the questionnaires can produce unreliable results, a calibration of the categories by weight is proposed via fragility functions to obtain a vulnerability index. Finally, the developed methodology is applied to a case study of school buildings in Italy.
Bulletin of Earthquake Engineering, 2015
Engineering Structures, 2014
ABSTRACT Reinforced Concrete (RC) walls are defined as large lightly reinforced walls if they are... more ABSTRACT Reinforced Concrete (RC) walls are defined as large lightly reinforced walls if they are not provided of high reinforcement percentage or if they are lack of reinforcement details usually required to improve the ductility of the structure. This type of walls gained relevance in 1950s–1970s constructions because of their good performances under seismic actions. Real earthquakes have, indeed, demonstrated that buildings constructed with large lightly reinforced walls, characterised by adequate area respect to the floor extension, could suffer lower damages in comparison with traditional RC framed buildings. Moreover, a widespread use of such a construction typology is outstanding thanks to the diffusion on the market of new types of integrated formworks, including insulating materials such as polystyrene, that are being used for casting concrete and are aimed to obtain a higher energetic efficiency and build structures made of continuous lightly reinforced walls. Nevertheless, there is a lack of both experimental information and specific design indications in technical codes on this type of construction. This paper firstly reviews the European code requirements for large lightly reinforced walls. Then, some experimental tests on RC walls in the existing literature are studied in detail also by means of a nonlinear Finite Element (FE) model. Finally, the performances of a whole RC building designed with both large lightly reinforced walls along the perimeter and internal frames have been also exploited by linear dynamic and static nonlinear analysis. The analysis are mainly aimed to highlight the influence of in-plane stiffness of the floor on the dynamic behaviour of the structure and to assess the contribution of both ductility and over-strength to the behaviour factor, i.e. to the seismic performance of such type of buildings, considering the lack of information in the technical literature about these features.