Il file contiene il REPORT relativo alla visita tecnica nelle zone colpite dalla sequenza sismica dell’Italia centrale 2016, in data 6-7 Luglio 2017 presso i comuni di Camerino e Visso (MC).
Il file contiene il REPORT relativo alla visita tecnica nelle zone colpite dalla sequenza sismica dell’Italia centrale 2016, in data 6-7 Luglio 2017 presso i comuni di Camerino e Visso (MC).
Il corso considera i problemi di concezione, di progettazione, di analisi strutturale e di tecnologia delle costruzioni metalliche, con particolare riguardo a quelle in acciaio. Alla fine del corso, lo Studente: 1) completerà ed estenderà le conoscenze teoriche e i procedimenti operativi per l’analisi ed il progetto delle costruzioni metalliche; 2) avrà competenze per concepire, progettare e verificare costruzioni complesse, in particolare edifici alti; acquisirà capacità 3) di giudizio e di 4) comunicazione di idee, informazioni, dati, problemi e soluzioni relativi alle costruzioni metalliche; inoltre, 5) potrà sviluppare attività di ricerca su temi piu' moderni e specialistici relativi alle costruzioni metalliche.
Michael Nieves.
We consider a transition wave that propagates inside a discrete periodic structure, composed of massless beams and periodically placed masses, as a result of energy supplied by a remote point load. This scenario may represent the collapse of a civil engineering structure, such as a rooftop or a bridge, due to some unwanted vibrations.
A summary of analytical results, obtained using the Wiener-Hopf technique, concerning the dynamic behaviour of the structure during the collapse is given.
The structure’s dispersive nature is then used to reveal the steady-state collapse speeds observed in numerical simulations. We show that average speed of collapse propagation is a continuous function of the load amplitude and identify intervals when steady-state propagation occurs. Outside these intervals, the collapse propagates non-steadily, and can oscillate rapidly. Here the collapse can occur in small bursts or clusters and for large load amplitudes it possesses what was recently discovered as a forerunning propagation.
Michael Nieves gratefully acknowledges the support of the EU H2020 grant MSCA-IF-2016-747334-CAT-FFLAP.
Bridges with hinged spans after a centenary experienceDCEE2017
Pier Giorgio Malerba.
Several steel and R.C. continuous bridges of the last century were made statically determinate by
placing hinge connections in suitable points of their spans (articulated bridges). The main
advantages of this choice are a clear and simple static scheme and the avoidance of spurious effect
due to settlements of the foundations.
On the other hand, the systematic use of bearing supports and joints along the spans causes slope
discontinuities of the road platform: under the permanent loads, such kinks are progressively
increased by shrinkage, creep and steel relaxation effects; under the traffic loads these local
discontinuities foster the dynamic effects in the neighbourhood of the hinges and causes severe
damages both at these devices and at their interfaces with the body of the main structure. Moreover,
these effects are an inconvenience as far as the appearance of the structure and ride comfort.
This contribution would present an overview of the performance of these bridges after a century of
experiences and to highlight their most diffused drawbacks. Particular attention is paid to the hinge
connections made of a couple of opposite R.C. corbels, which is one of the most critical zones. In
fact, their shape made difficult the detailing of the bars, frequently quite congested, attracts and
retains the damaging agents (salted water from the platform) and, as a consequence, gives rise to
fast corrosion states. Some criteria for their structural assessment are given and the examples of
rehabilitation are presented.
Collapse propagation in bridge structures. A semi-analytical modelDCEE2017
Michele Brun.
We consider the advance of a transition flexural wave through a beam-like periodically supported slender structure. The
collapse of a bridge structure is modeled as a steady-state propagation of a transition wave within a slender structure. The problem is
governed by fourth-order partial differential equations and both propagating and evanescent waves are included in the general solution. It is
shown that the problem can be expressed within a class of functional equations of the Wiener-Hopf type . Three different propagation
regimes are found: subsonic, intersonic and supersonic and it is shown that propagation is restricted to the intersonic regime where part of the
energy is released to the damaged structure.
Applications to the study of the collapse of the San Saba bridge in Texas shows the validity of the model.
International Journal of Structural Glass and Advanced Materials Research. Sp...DCEE2017
The document announces a special issue of the International Journal of Structural Glass and Advanced Materials Research on "Current Challenges in Materials Design". The special issue will include selected papers presented at the 6th International Workshop on Design for Civil and Environmental Engineering. Potential topics include new engineered materials, design methodology, and interdisciplinary challenges in engineering design. The guest editors are Chiara Bedon, Fausto Mistretta, Mauro Sassu, and Flavio Stochino of the University of Cagliari. The submission deadline is January 31, 2018.
1. Tecnica delle Costruzioni deals with structural design and analysis, bringing together various ideas, theories, methods, tools, and principles to inform the design of structural elements and materials.
2. Structural design requires a holistic view of a construction's entire lifecycle and environment, and necessarily involves making decisions while assuming responsibility.
3. Structural analysis is essential for understanding structural behavior both qualitatively and quantitatively in terms of performance and safety, and properly relating analytical models to real-world structures.
Knowledge acquisition of existing buildings by means of diagnostic surveying....DCEE2017
Giovanna Concu.
The issue of assessing the structural adequacy of existing buildings involves several problems when a unique and reliable strategy of modelling and analyzing is looked for. This is mainly related to the peculiarity of each construction in a context of broad variety. In this light the structural model and consequently the judgment on structural adequacy should be derived from a process of knowledge of the construction carried through steps of different reliability. This paper focuses on a fundamental step of the knowledge acquisition process, which is the surveying campaign aimed at assessing some of the parameter to be implemented into the structural model (geometry, detailing and properties of the materials). The main aspects of a proper and effective planning of the diagnostic campaign are issued and discussed also with reference to some case studies. Special emphasis is given to the usefulness of non-destructive testing methods, the criteria underlying their selection and the relevance of their calibration.
Infrared Thermography for the Characterization of Painted Vaults of Historic ...DCEE2017
Claudia Casapulla.
The infrared thermography is a type of non-destructive investigation which can find interesting application in acquiring information about the structural features of ancient masonry buildings. In this case, in fact, the needs of preservation of the historical values have to be compound with the needs of achieving a proper level of knowledge of the parameters influencing the structural behaviour in order to perform a reliable evaluation of their seismic safety. A recent application of the infrared thermography was proposed in the framework of the Project on the seismic evaluation of the Museum of Capodimonte in Naples (Italy). The objective was to clarify if the painted vaults covering some rooms could have structural function and to identify their constructive typology. In this circumstance, an interesting methodological approach, with more general validity, has been developed by integrating the instrumental investigations with different sources of information, such as historical documents and hypotheses of critical interpretation.
Dynamic behavior of a historical tower subjected to bells’ forced vibrations DCEE2017
Dora Foti.
The aim of the paper is to assess the dynamic behavior of the bell tower of the Basilica Church “S.S. Medici” one of the most important church in the town of Bitonto, Bari, Italy. The tower is 55 m tall and it is made in reinforced concrete. The tower is totally disconnected from the structure of the Church. It was considered the effect of ambient vibration force and, for the forced tests, the excitation produced by different bells. Four bells are housed in the bell chamber, while four more bells are housed at a higher level. All the bells are directly connected to the tower so that their movement introduce an excitation swinging force to the tower. The accelerations at different points have been recorded by 11 piezoelectric accelerometers positioned at four levels of the bell tower. The results of the experimental tests have been analyzed in order to estimate the modal parameters of the tower and to calibrate a 3D finite element model of the tower useful to check the vulnerability of the tower.
Axiomatic Design and the Specification of Surface TopographiesDCEE2017
Christopher A. Brown.
Surfaces on architectural and civil engineering structures should often fulfill several functions, e.g., aesthetics, cleanability, heat transfer, and friction. A road or runway surface, for example, must satisfy two functional requirements (FRs): FR1) provide a comfortable ride without excessive vertical motion, and FR2) facilitate stopping and turning with sufficient friction. The FR1 requires smooth surface and FR2 favors rough. Suh’s axioms requires a DP for each FR. The DPs are physical attributes that fulfill the FRs. The complete design solution includes an integrated CEME (collectively exhaustive, mutually exclusive) decomposition hierarchy, from abstract to detailed, of the design problem. Pairs of FRs and their corresponding DPs, are related by design equations. Axiomatic design and multiscale analysis in surface metrology address these kinds of specifications.
Interdisciplinary challenges in design of windblown sand barriers around dese...DCEE2017
1) The document discusses interdisciplinary challenges in designing windblown sand barriers around desert railways. It involves fields like geomorphology, aeolian research, railway engineering, structural engineering, applied mathematics, fluid mechanics, granular mechanics, and wind engineering.
2) The project aims to develop effective sand mitigation measures (SMM) to address sand limit states that threaten railway operations through a phenomenon- and computational-based design approach.
3) The design process involves setting sand limit states, analyzing incoming windblown sand conditions, categorizing and designing potential SMMs, and assessing SMM performance through simulations and tests from conceptual design to implementation.
Innovative education: Information Asymmetry applied to Building Engineering a...DCEE2017
This document describes an experiment conducted by researchers from Politecnico di Milano and Politecnico di Torino to address students' sectorial approaches to complex issues in building engineering and architecture curricula. The experiment involved having student teams plan and budget a dinner for 20 people with €600, with one team having full information and the other receiving information gradually. The results showed that the team with full information from the start managed resources better. The researchers propose that introducing information asymmetry can help address students' tendency towards sectorial thinking and better prepare them for multidisciplinary problems.
Multidisciplinary workshop on building designDCEE2017
Giuseppe Desogus.
The presentation shows an innovative model of integrated workshop on building design. It is aimed at improving the students’ knowledge on the importance of a collaborative approach among both architectural and technical specialists. Such an approach once was adopted only for main architectural works. Nowadays, however, the increasing necessity of both structural (seismic) and energy performances of the buildings requires a more complex approach also in ordinary ones design.
The workshop is part of the course for the master degree in Architecture of the University of Cagliari. It is composed by three modules: Architectural Engineering, Structural Design and Physics Engineering. The single theory modules are less than an half of the semester. Most of the time is dedicated to a practical workshop in which the students are divided into groups and work on a assigned design theme. Last year it was the revisiting of three buildings designed by Mario de Renzi, one of the main architects of Italian modernism. The aim of the workshop is giving the students a first-hand experience on the importance that every choice on the architectural field has on structural and energy performance ones and vice versa.
The results are quite encouraging. The workshop constantly receives positive feedbacks in the students’ evaluation questionnaires and it is above the average rating of the course.
The main strength is the systemic approach that results in outputs that are far beyond what could have been done teaching the same subjects separately. In the future a new module on Building Information Modelling will be added to the workshop. It could give the possibility to better structure and manage the interactions between architectural and technical aspects.
An on-site teaching laboratory in a village damaged by the 2009 Abruzzo earth...DCEE2017
Linda Giresini.
This paper illustrates an on-site teaching laboratory that involved forty students of the School of Engineering at Pisa during the whole summers of 2010 and 2011. The activity consisted in a systematic survey of damages occurred in a small village after the 2009 Abruzzo earthquake and in the preparation of documents addressed to a reconstruction plan. The historical village of San Pio delle Camere (1000 inhabitants) was fully surveyed, including about 140 hypogean sites. Each student spent at least one month in these activities, funded by specific study grants provided by the Italian Tuscany Region. Teams of three-four students performed well-defined work packages, led by a tutor, who established roles and functions in the group. At the end of each day, the students discussed the progress made preparing also a weekly report. In the last phases, preliminary structural analyses were carried out to assess the seismic vulnerability of some relevant buildings, fully available to the students. The main results were published in a book presented in a workshop and used to set up the official reconstruction plan of the village. During this on-site laboratory, the students could experience the effects of the destructive earthquake on the population, visiting also the damaged surrounding towns and seeing with their own eyes many cases of structural collapse.
A didactical laboratory of structural engineering for bachelor civil engineer...DCEE2017
This document describes a didactical laboratory for structural engineering students at the University of Cagliari. The course was divided into two semesters, with the second semester involving an individual structural design project. Students were assigned similar plane frame structures with variations in measurements, locations, and uses. Working in groups with a tutor, students progressed through the design process over 12 sessions. This approach aimed to train students through the student-tutor relationship, student collaboration, and exposure to a real design project. Most students completed the project on time and achieved good evaluation results. The laboratory provided an effective way to apply theoretical knowledge in a practical setting.
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Similar to Analisi di collassi strutturali nella prospettiva dell’ingegneria forense
Il corso considera i problemi di concezione, di progettazione, di analisi strutturale e di tecnologia delle costruzioni metalliche, con particolare riguardo a quelle in acciaio. Alla fine del corso, lo Studente: 1) completerà ed estenderà le conoscenze teoriche e i procedimenti operativi per l’analisi ed il progetto delle costruzioni metalliche; 2) avrà competenze per concepire, progettare e verificare costruzioni complesse, in particolare edifici alti; acquisirà capacità 3) di giudizio e di 4) comunicazione di idee, informazioni, dati, problemi e soluzioni relativi alle costruzioni metalliche; inoltre, 5) potrà sviluppare attività di ricerca su temi piu' moderni e specialistici relativi alle costruzioni metalliche.
Michael Nieves.
We consider a transition wave that propagates inside a discrete periodic structure, composed of massless beams and periodically placed masses, as a result of energy supplied by a remote point load. This scenario may represent the collapse of a civil engineering structure, such as a rooftop or a bridge, due to some unwanted vibrations.
A summary of analytical results, obtained using the Wiener-Hopf technique, concerning the dynamic behaviour of the structure during the collapse is given.
The structure’s dispersive nature is then used to reveal the steady-state collapse speeds observed in numerical simulations. We show that average speed of collapse propagation is a continuous function of the load amplitude and identify intervals when steady-state propagation occurs. Outside these intervals, the collapse propagates non-steadily, and can oscillate rapidly. Here the collapse can occur in small bursts or clusters and for large load amplitudes it possesses what was recently discovered as a forerunning propagation.
Michael Nieves gratefully acknowledges the support of the EU H2020 grant MSCA-IF-2016-747334-CAT-FFLAP.
Bridges with hinged spans after a centenary experienceDCEE2017
Pier Giorgio Malerba.
Several steel and R.C. continuous bridges of the last century were made statically determinate by
placing hinge connections in suitable points of their spans (articulated bridges). The main
advantages of this choice are a clear and simple static scheme and the avoidance of spurious effect
due to settlements of the foundations.
On the other hand, the systematic use of bearing supports and joints along the spans causes slope
discontinuities of the road platform: under the permanent loads, such kinks are progressively
increased by shrinkage, creep and steel relaxation effects; under the traffic loads these local
discontinuities foster the dynamic effects in the neighbourhood of the hinges and causes severe
damages both at these devices and at their interfaces with the body of the main structure. Moreover,
these effects are an inconvenience as far as the appearance of the structure and ride comfort.
This contribution would present an overview of the performance of these bridges after a century of
experiences and to highlight their most diffused drawbacks. Particular attention is paid to the hinge
connections made of a couple of opposite R.C. corbels, which is one of the most critical zones. In
fact, their shape made difficult the detailing of the bars, frequently quite congested, attracts and
retains the damaging agents (salted water from the platform) and, as a consequence, gives rise to
fast corrosion states. Some criteria for their structural assessment are given and the examples of
rehabilitation are presented.
Collapse propagation in bridge structures. A semi-analytical modelDCEE2017
Michele Brun.
We consider the advance of a transition flexural wave through a beam-like periodically supported slender structure. The
collapse of a bridge structure is modeled as a steady-state propagation of a transition wave within a slender structure. The problem is
governed by fourth-order partial differential equations and both propagating and evanescent waves are included in the general solution. It is
shown that the problem can be expressed within a class of functional equations of the Wiener-Hopf type . Three different propagation
regimes are found: subsonic, intersonic and supersonic and it is shown that propagation is restricted to the intersonic regime where part of the
energy is released to the damaged structure.
Applications to the study of the collapse of the San Saba bridge in Texas shows the validity of the model.
International Journal of Structural Glass and Advanced Materials Research. Sp...DCEE2017
The document announces a special issue of the International Journal of Structural Glass and Advanced Materials Research on "Current Challenges in Materials Design". The special issue will include selected papers presented at the 6th International Workshop on Design for Civil and Environmental Engineering. Potential topics include new engineered materials, design methodology, and interdisciplinary challenges in engineering design. The guest editors are Chiara Bedon, Fausto Mistretta, Mauro Sassu, and Flavio Stochino of the University of Cagliari. The submission deadline is January 31, 2018.
1. Tecnica delle Costruzioni deals with structural design and analysis, bringing together various ideas, theories, methods, tools, and principles to inform the design of structural elements and materials.
2. Structural design requires a holistic view of a construction's entire lifecycle and environment, and necessarily involves making decisions while assuming responsibility.
3. Structural analysis is essential for understanding structural behavior both qualitatively and quantitatively in terms of performance and safety, and properly relating analytical models to real-world structures.
Knowledge acquisition of existing buildings by means of diagnostic surveying....DCEE2017
Giovanna Concu.
The issue of assessing the structural adequacy of existing buildings involves several problems when a unique and reliable strategy of modelling and analyzing is looked for. This is mainly related to the peculiarity of each construction in a context of broad variety. In this light the structural model and consequently the judgment on structural adequacy should be derived from a process of knowledge of the construction carried through steps of different reliability. This paper focuses on a fundamental step of the knowledge acquisition process, which is the surveying campaign aimed at assessing some of the parameter to be implemented into the structural model (geometry, detailing and properties of the materials). The main aspects of a proper and effective planning of the diagnostic campaign are issued and discussed also with reference to some case studies. Special emphasis is given to the usefulness of non-destructive testing methods, the criteria underlying their selection and the relevance of their calibration.
Infrared Thermography for the Characterization of Painted Vaults of Historic ...DCEE2017
Claudia Casapulla.
The infrared thermography is a type of non-destructive investigation which can find interesting application in acquiring information about the structural features of ancient masonry buildings. In this case, in fact, the needs of preservation of the historical values have to be compound with the needs of achieving a proper level of knowledge of the parameters influencing the structural behaviour in order to perform a reliable evaluation of their seismic safety. A recent application of the infrared thermography was proposed in the framework of the Project on the seismic evaluation of the Museum of Capodimonte in Naples (Italy). The objective was to clarify if the painted vaults covering some rooms could have structural function and to identify their constructive typology. In this circumstance, an interesting methodological approach, with more general validity, has been developed by integrating the instrumental investigations with different sources of information, such as historical documents and hypotheses of critical interpretation.
Dynamic behavior of a historical tower subjected to bells’ forced vibrations DCEE2017
Dora Foti.
The aim of the paper is to assess the dynamic behavior of the bell tower of the Basilica Church “S.S. Medici” one of the most important church in the town of Bitonto, Bari, Italy. The tower is 55 m tall and it is made in reinforced concrete. The tower is totally disconnected from the structure of the Church. It was considered the effect of ambient vibration force and, for the forced tests, the excitation produced by different bells. Four bells are housed in the bell chamber, while four more bells are housed at a higher level. All the bells are directly connected to the tower so that their movement introduce an excitation swinging force to the tower. The accelerations at different points have been recorded by 11 piezoelectric accelerometers positioned at four levels of the bell tower. The results of the experimental tests have been analyzed in order to estimate the modal parameters of the tower and to calibrate a 3D finite element model of the tower useful to check the vulnerability of the tower.
Axiomatic Design and the Specification of Surface TopographiesDCEE2017
Christopher A. Brown.
Surfaces on architectural and civil engineering structures should often fulfill several functions, e.g., aesthetics, cleanability, heat transfer, and friction. A road or runway surface, for example, must satisfy two functional requirements (FRs): FR1) provide a comfortable ride without excessive vertical motion, and FR2) facilitate stopping and turning with sufficient friction. The FR1 requires smooth surface and FR2 favors rough. Suh’s axioms requires a DP for each FR. The DPs are physical attributes that fulfill the FRs. The complete design solution includes an integrated CEME (collectively exhaustive, mutually exclusive) decomposition hierarchy, from abstract to detailed, of the design problem. Pairs of FRs and their corresponding DPs, are related by design equations. Axiomatic design and multiscale analysis in surface metrology address these kinds of specifications.
Interdisciplinary challenges in design of windblown sand barriers around dese...DCEE2017
1) The document discusses interdisciplinary challenges in designing windblown sand barriers around desert railways. It involves fields like geomorphology, aeolian research, railway engineering, structural engineering, applied mathematics, fluid mechanics, granular mechanics, and wind engineering.
2) The project aims to develop effective sand mitigation measures (SMM) to address sand limit states that threaten railway operations through a phenomenon- and computational-based design approach.
3) The design process involves setting sand limit states, analyzing incoming windblown sand conditions, categorizing and designing potential SMMs, and assessing SMM performance through simulations and tests from conceptual design to implementation.
Innovative education: Information Asymmetry applied to Building Engineering a...DCEE2017
This document describes an experiment conducted by researchers from Politecnico di Milano and Politecnico di Torino to address students' sectorial approaches to complex issues in building engineering and architecture curricula. The experiment involved having student teams plan and budget a dinner for 20 people with €600, with one team having full information and the other receiving information gradually. The results showed that the team with full information from the start managed resources better. The researchers propose that introducing information asymmetry can help address students' tendency towards sectorial thinking and better prepare them for multidisciplinary problems.
Multidisciplinary workshop on building designDCEE2017
Giuseppe Desogus.
The presentation shows an innovative model of integrated workshop on building design. It is aimed at improving the students’ knowledge on the importance of a collaborative approach among both architectural and technical specialists. Such an approach once was adopted only for main architectural works. Nowadays, however, the increasing necessity of both structural (seismic) and energy performances of the buildings requires a more complex approach also in ordinary ones design.
The workshop is part of the course for the master degree in Architecture of the University of Cagliari. It is composed by three modules: Architectural Engineering, Structural Design and Physics Engineering. The single theory modules are less than an half of the semester. Most of the time is dedicated to a practical workshop in which the students are divided into groups and work on a assigned design theme. Last year it was the revisiting of three buildings designed by Mario de Renzi, one of the main architects of Italian modernism. The aim of the workshop is giving the students a first-hand experience on the importance that every choice on the architectural field has on structural and energy performance ones and vice versa.
The results are quite encouraging. The workshop constantly receives positive feedbacks in the students’ evaluation questionnaires and it is above the average rating of the course.
The main strength is the systemic approach that results in outputs that are far beyond what could have been done teaching the same subjects separately. In the future a new module on Building Information Modelling will be added to the workshop. It could give the possibility to better structure and manage the interactions between architectural and technical aspects.
An on-site teaching laboratory in a village damaged by the 2009 Abruzzo earth...DCEE2017
Linda Giresini.
This paper illustrates an on-site teaching laboratory that involved forty students of the School of Engineering at Pisa during the whole summers of 2010 and 2011. The activity consisted in a systematic survey of damages occurred in a small village after the 2009 Abruzzo earthquake and in the preparation of documents addressed to a reconstruction plan. The historical village of San Pio delle Camere (1000 inhabitants) was fully surveyed, including about 140 hypogean sites. Each student spent at least one month in these activities, funded by specific study grants provided by the Italian Tuscany Region. Teams of three-four students performed well-defined work packages, led by a tutor, who established roles and functions in the group. At the end of each day, the students discussed the progress made preparing also a weekly report. In the last phases, preliminary structural analyses were carried out to assess the seismic vulnerability of some relevant buildings, fully available to the students. The main results were published in a book presented in a workshop and used to set up the official reconstruction plan of the village. During this on-site laboratory, the students could experience the effects of the destructive earthquake on the population, visiting also the damaged surrounding towns and seeing with their own eyes many cases of structural collapse.
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This document describes a didactical laboratory for structural engineering students at the University of Cagliari. The course was divided into two semesters, with the second semester involving an individual structural design project. Students were assigned similar plane frame structures with variations in measurements, locations, and uses. Working in groups with a tutor, students progressed through the design process over 12 sessions. This approach aimed to train students through the student-tutor relationship, student collaboration, and exposure to a real design project. Most students completed the project on time and achieved good evaluation results. The laboratory provided an effective way to apply theoretical knowledge in a practical setting.
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A BIM-based methodology can help in setting parameters for the proper optimization of the façade, balancing production related needs and design requirements. The proposed method allows the exploration of alternatives (known as Design Optioneering) to optimize the choice of façade elements.
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A multi-year experience on structural rehabilitation of several archaeological sites was performed with a series of groups of MsC students in Civil Engineering of the University of Pisa. The activity was carried out from 2004 to 2012 and involved about forty students. The students were organized in groups of two, together with other students of faculty of Archaeology, with the task of overseeing teams of local workers engaged in rehabilitation activities. The activity was started by the teacher and by skilled civil engineers to establish the working phases. After a short course to receive the basic instructions to follow the established UNESCO procedure for consolidation, the students themselves conducted the works on site for a period of about four weeks. Together with the technical problems with the management of a construction site, they addressed the issue of language, as many Indian or Pakistani workers did not speak English, and the necessity to manage the activity arranging the groups in terms of compatibility and work capacity. The full-immersion in an Islamic country (Sultanate of Oman), in a security-protected situation, permitted to enable them to gain knowledge of places and people in depth, living in close contact with the Arab, Indian and Pakistani communities.
Convegno SPEKTRA da A2A - 28 maggio 2024 | VEIRANA Francesco
Analisi di collassi strutturali nella prospettiva dell’ingegneria forense
1. Analisi di tre collassi strutturali dovuti a eventi
sismici nella prospettiva dell’ingegneria forense
Maria Gabriella Mulas
Cagliari, 30 novembre 2018
“Analisi di collassi strutturali nella prospettiva
dell’ingegneria forense”
2. Maria Gabriella Mulas
Premessa – I crolli
6 aprile 2009 L’Aquila
2
• La «Casa dello Studente» (1965),
via XX Settembre 46, 8 morti
• Edificio a tre corpi: la sola Ala
Nord subisce un collasso parziale
• Via D’Annunzio 24/26 (1961), 11
morti
• Collasso tipo pancake, che
coinvolge parzialmente anche il
semi-interrato
3. Maria Gabriella Mulas
Premessa – I crolli
29 maggio 2012, Medolla (MO)
• Stabilimento Haemotronic, 4 morti (2002)
• L’edificio aveva resistito al sisma del 20 maggio 2012
• Struttura prefabbricata, connessioni ad attrito; collasso parziale di una
zona dell’area produttiva.
• Caduta per ribaltamento di travi di copertura; collasso nella sezione di
base per cinque colonne (una collassa anche in una sezione intermedia)
3
4. Maria Gabriella Mulas
PER NON DIMENTICARE
VIA D’ANNUNZIO
Matteo Vannucci
Carmelina Iovine
Marco Santosuosso
Stefano Antonini
Giuliana Tamburro
Marino Tamburro
Giuseppe Lippi
Wilma Gasperini
Giovanna Lippi
Liberio Muzi
Maria Giuseppina De Nuntis
4
HAEMOTRONIC
Matteo Serra
Giordano Visconti
Biagio Santucci
Paolo Siclari
CASA DELLO STUDENTE
Luciana Pia Capuano
Francesco Esposito
Alessio Di Simone
Davide Centofanti
Hamade Hussein
Marco Alviani
Luca Lunari
Angela Antonia Cruciano
5. Maria Gabriella Mulas
Le perizie (who’s who)
Casa dello Studente: ottobre 2010 – novembre 2011 (ottobre 2012)
Perito del giudice Maria Gabriella Mulas
Ausiliari: Dario Coronelli (materiali), Luca Martinelli (rilievi e modelli
numerici), Roberto Paolucci (sisma), Federico Perotti (analisi
meccanismo di collasso), Angela Pavesi e Nicoletta Volpin (aspetti
amministrativi), Stefano Ceresa (aspetti giuridici della perizia)
Haemotronic: dicembre 2012 – marzo 2014 (giugno 2014)
Collegio peritale Maria Gabriella Mulas, Patrick Bamonte (edificio:
modellazione numerica e materiali) e Roberto Paolucci (sisma)
Ausiliari: Rosmaria Pantalena (verifica fondazioni), Daniela Melissari
Via D’Annunzio: marzo 2013 – giugno 2013 (dicembre 2013)
Perito del giudice Maria Gabriella Mulas
Ausiliari: Dario Coronelli (materiali), Chiara Smerzini (sisma), Rosmaria
Pantalena (modelli numerici)
5
6. Maria Gabriella Mulas
Le domande chiave
1. Come è crollato l’edificio?
2. Quali sono le cause del crollo?
3. Ci sono responsabilità umane nel crollo?
Art. 40 C.P.
Nessuno può essere punito per un fatto preveduto dalla
legge come reato, se l'evento dannoso o pericoloso, da cui
dipende la esistenza del reato, non è conseguenza della
sua azione od omissione.
Non impedire un evento, che si ha l'obbligo giuridico di
impedire, equivale a cagionarlo.
6
7. Maria Gabriella Mulas
Come è crollato l’edificio: modalità di
collasso
1. Obiettivo: ricostruzione della dinamica del collasso «altamente
probabile» a partire dalle evidenze materiali, documentali e (ove
possibile) testimoniali disponibili
Geometria dell’edificio al momento del crollo
Carichi permanenti/variabili agenti
Proprietà dei materiali da costruzione impiegati
Proprietà modali dell’edificio
Caratterizzazione del sisma
Descrizione dei danni nelle parti sopravvissute e in quelle
collassate In sito
7
Progetto
vs sito
Analisi numeriche
Registrazioni accelerometriche
Stratigrafia e topografia del sito
8. Maria Gabriella Mulas
Come è crollato l’edificio: modalità di
collasso
2. Come determinate la geometria dell’edificio: tavole di progetto e
rilievi in sito
8
Edifici anni ’60: telai in c.a. gettati in
opera
Tavole progettuali solo in minima
parte disponibili
Mancanza di dettagli delle
armature
Discrepanze tra il progettato e il
costruito
La geometria delle parti
collassate è solo parzialmente
nota: fondamentale esaminare i
reperti estratti dalle macerie
RUOLO CHIAVE DEI
RILIEVI IN SITO
Edificio del 2000: struttura
prefabbricata con connessioni ad
attrito
Tavole progettuali disponibili
Dettagli delle armature noti
Non ci sono discrepanze tra il
progettato e il costruito
Pareti non strutturali hanno
svolto un ruolo strutturale
CONOSCENZA DELLA
STRUTTURA DOVUTA AL
PROGETTO E SOLO
CONFERMATA DAI RILIEVI IN
SITO
9. Maria Gabriella Mulas
Come è crollato l’edificio: modalità di
collasso
3. Carichi permanenti e variabili agenti
9
Edifici anni ’60
Mancano normative chiare di
riferimento per i valori dei carichi
permanenti e accidentali da
considerare
CdS: discrepanze tra progettato
e il costruito; ulteriori modifiche
legate a interventi di
ristrutturazione successivi
Edificio prefabbricato del 2000:
Carichi progettuali ben definiti
dalle normative in vigore
Discrepanza significativa
legata all’inserimento di
pavimenti industriali (massetti
in c.a.) non previsti a progetto
Necessario stabilire il peso dei
macchinari per il trattamento
aria posti al primo piano
(permanenti vs variabili?)
RUOLO CHIAVE DEI RILIEVI IN SITO
PER LA VALUTAZIONE DEI CARICHI PERMANENTI
10. Maria Gabriella Mulas
Come è crollato l’edificio: modalità di
collasso
4. Materiali da costruzione
10
Edifici anni ’60
Pochi controlli nel confeziona-
mento del cls
Normativa di riferimento per la
resistenza è del 1939; le
relazioni di calcolo sono
lacunose
Prove in sito sono indispensabili
Carotaggi eseguiti sia sulle parti
sopravvissute che su quelle
collassate
Risultati segnalano valori molto
dispersi con medie basse
RUOLO CHIAVE DEI
RILIEVI IN SITO
Edificio prefabbricato del 2000:
Processo di produzione del
calcestruzzo dei prefabbricati
molto controllato.
Valori progettuali ben definiti
dalle normative in vigore
Mancanza di certificazione
sulle parti gettate in opera
RILIEVI IN SITO NECESSARI
SOLO PER CONFERMA DEI
VALORI PROGETTUALI
11. Maria Gabriella Mulas
Come è crollato l’edificio: modalità di
collasso
5. Proprietà modali dell’edificio necessarie per:
Valutare le forme modali e confrontarle con il meccanismo di
collasso
Stabilire un range entro cui possono cadere i periodi propri
significativi, al fine di valutare le sollecitazioni spettrali
11
Edifici anni ’60
Strutture intelaiate relativamente
semplici da modellare
Importanti le condizioni al
contorno dei piani interrati
Incertezze nelle geometrie di
molti elementi strutturali (es. le
travi in spessore)
Per la CdS occorre modellare
anche i solai
Considerare la variabilità di EJ
Edificio prefabbricato del 2000:
Connessioni ad attrito
Aste a geometria variabile:
colonne, travi doppia pendenza
Solai con elementi nervati
(piastra ortotropa)
Pareti «non strutturali»:
contributi di massa e rigidezza
Plinti a bicchiere alla base delle
colonne.
12. Maria Gabriella Mulas
Come è crollato l’edificio: modalità di
collasso
6. Caratterizzazione del sisma (Roberto Paolucci e Chiara Smerzini)
12
6 Aprile 2009, L’Aquila
Necessario scegliere la stazione
accelerometrica di cui utilizzare
la registrazione
Determinazione del profilo
stratigrafico al sito
Determinazione del segnale al
sito (deconvoluzione al bedrock
e convoluzione al sito)
Valutazione degli effetti
topografici
Rotazione del segnale lungo le
direzioni principali dell’edificio
con determinazione dello spettro
elastico
29 Maggio 2012, Medolla
Necessario confrontarsi con il
precedente evento del 20.5 e
scegliere la stazione
accelerometrica
Profili stratigrafici poco variabili
e stazione accelerometrica
molto vicina, non è necessario
trasportare il segnale al sito
Rotazione del segnale lungo le
direzioni principali dell’edificio
con determinazione dello
spettro elastico per entrambi gli
eventi
13. Mulas et al – Paper #5833 - WCEE 2012 - Lisboa
GROUND MOTION AT CASA DELLO STUDENTE 13
• Ground motion records available
at AQK and AQU stations
• DH tests to evaluate the Vs profile at the
site
• 1D linear-equivalent analysis to evaluate
ground motion at CdS based on AQK
record and the Vs profile at AQK and CdS
response spectrum
14. Maria Gabriella Mulas
Come è crollato l’edificio: modalità di
collasso
7. Descrizione dei danni nelle parti sopravvissute e in quelle collassate
Occorre un rilievo sistematico dei danni visibili
Rilievi fotografici indispensabili per mappare i danni, strutturali e
non strutturali
Rilievi fotografici sono indispensabili soprattutto se si prevede
che l’edificio verrà demolito (diventano accertamenti tecnici non
ripetibili)
L’edificio deve essere analizzato nella sua interezza, fino alle
fondazioni (ove possibile).
14
Oggi sono disponibili tecniche più avanzate (fotogrammetria,
uso dei droni, etc) ma anche più costose
15. Maria Gabriella Mulas
Come è crollato l’edificio: modalità di
collasso
8. Ricostruzione del meccanismo di collasso
Non esiste una ricetta pre-confezionata…
Il giudizio ingegneristico è fondamentale nel formulare ipotesi
significative e verificare che soddisfino tutti i dati a disposizione
(sisma, evidenze «sperimentali», analisi numeriche,
testimonianze)
15
16. Maria Gabriella Mulas
Le cause del crollo: il sisma
La domanda pregiudiziale:
L’edificio è crollato a causa del sisma, da considerarsi come un
evento eccezionale e quindi «assorbente» tutte le altre cause?
16
29 Maggio 2012, Medolla
Evento in linea con la sismicità
dell’area (faglia nota), anche se
caratterizzato da bassa
probabilità
Il comune non era compreso
nella zonazione sismica, non
esiste un valore di riferimento
Procedimento archiviato: ??
Non c’è risposta
6 Aprile 2009, L’Aquila
Evento registrato in linea con la
sismicità dell’area e simile negli
effetti a precedenti eventi storici
La Corte di Cassazione si è già
pronunciata sulla non-
eccezionalità dell’evento
Per gli edifici in esame,
l’intensità del sisma era
compatibile con i valori delle
normative del 1937 e 1962
La quasi totalità degli edifici in
c.a. non è crollata
17. Maria Gabriella Mulas
Deficitstrutturale
Le norme tecniche all’atto della
progettazione erano adeguate?
Il progetto originario rispettava le
norme in vigore?
L’edificio è stato costruito
conformemente al progetto?
Sono sopravvenute modifiche che hanno
alterato il comportamento meccanico?
Sono sopravvenute modifiche che
richiedevano un adeguamento sismico?
Le modifiche introdotte sono state
causa del crollo?
La resistenza dei materiali era
conforme ai valori di progetto?
Fondazioni adeguate?
Le cause del crollo
Cause meccaniche del crollo: deficit strutturale
17
CasadelloStudente
Norme «adeguate»
NO: errore progettuale
NO: incrementi nei
carichi
SI (parete REI, incremento nei
carichi)
SI (destinazione d’uso)
NI
NO, ma il dato è
ininfluente
SI
18. Maria Gabriella Mulas
Deficitstrutturale
Le norme tecniche all’atto della
progettazione erano adeguate?
Il progetto originario rispettava le
norme in vigore?
L’edificio è stato costruito
conformemente al progetto?
Sono sopravvenute modifiche che hanno
alterato il comportamento meccanico?
Sono sopravvenute modifiche che
richiedevano un adeguamento sismico?
Le modifiche introdotte sono state
causa del crollo?
La resistenza dei materiali era
conforme ai valori di progetto?
Fondazioni adeguate?
Le cause del crollo
Cause meccaniche del crollo: deficit strutturale
18
ViaD’Annunzio
Norme
«adeguate»
NO: progetto
inadeguato
Quasi SI
NO
SI (intervento di
natura statica)
NO
NO, il dato è
rilevante
SI
19. Maria Gabriella Mulas
Le cause del crollo
Cause meccaniche del crollo: deficit strutturale
19
Deficitstrutturale Le norme tecniche all’atto della
progettazione erano adeguate?
Il progetto originario rispettava le
norme in vigore?
L’edificio è stato costruito
conformemente al progetto?
Sono sopravvenute modifiche che hanno
alterato il comportamento meccanico?
Sono sopravvenute modifiche che
richiedevano un adeguamento sismico?
Le modifiche introdotte sono state
causa del crollo?
La resistenza dei materiali era
conforme ai valori di progetto?
Fondazioni adeguate?
Haemotronic
NO
SI
Parzialmente
In fase di
costruzione
NORMATIVA?
NO
SI
SI
20. Maria Gabriella Mulas
Le responsabilità umane nel crollo
cause ex-art. 40 CP
Capi di
imputazione
Ricostruzione
iter
amministrativo
Individuazione
degli «eventi»
Associazione tra
eventi e imputati
Quadro giuridico di
riferimento
«risalente» nazio-
nale e regionale
Normativa
tecnica;
collaudi; agibilità
post-sisma?
Normativa
urbanistica
Normativa
appalti pubblici;
lavoro;
sicurezza
20
Risposte ai
quesiti del
giudice
21. Maria Gabriella Mulas
Pubblicazioni scientifiche sul crollo della
Casa dello Studente
1. Mulas M.G., Coronelli D., Martinelli L., Paolucci R., Perotti F., Pavesi A., “Analysis of the “Casa dello
Studente” collapse during the L’Aquila 6th April 2009 earthquake”, Proceedings of the 15 WCEE (World
Conference on Earthquake Engineering), Paper n. 5833, Lisboa (Portugal) September 2012.
2. Mulas M.G., Coronelli D., Martinelli L., Paolucci R., Perotti F., “The collapse of the “Casa dello Studente
during the 2009 earthquake in L’Aquila”, IF CRASC ’12, II Convegno di Ingegneria Forense, V Convegno su
Crolli, Affidabilità Strutturale, Consolidamento. Pisa, 15-17 novembre 2012.
3. Mulas M.G., Perotti F., Coronelli D., Martinelli L., Paolucci R., “The partial collapse of “Casa dello
Studente” during L’Aquila 2009 earthquake”, Engineering Failure Analysis, Vol. 34, 566-584, 2013.
4. Mulas M.G., Martinelli L, Perotti F., “A case study of collapse during the 2009 L’Aquila (Italy) earthquake”,
COMPDYN 2013, 4th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics
and Earthquake Engineering. Kos Island, Greece, 12–14 June 2013.
5. Mulas M.G., Martinelli L., Perotti F. “An investigation on the collapse sequence of an RC frame during
L’Aquila 2009 earthquake”. SEMC 2013: The Fifth International Conference on Structural Engineering,
Mechanics and Computation, paper 465, Cape Town, South Africa, 2-4 September 2013.
6. Mulas M.G., Martinelli L., “Numerical simulation of seismic collapse of a rc framed building: a case study”,
Study and Researches, V. 34, pag. 11-29, 2015.
7. Mulas M.G. Martinelli P. “Non-linear dynamic analyses of an RC frame building collapsed during L’Aquila
2009 earthquake”. Proceedings of Compdyn 2017, 6th ECCOMAS Conference on Computational Methods in
Structural Dynamics and Earthquake Engineering, M. Papadrakakis, M. Fragiadakis (eds.), Rhodes Island,
Greece, 15–17 June 2017. Paper C18063.
8. Mulas M.G. Martinelli P. “Numerical simulation of the partial seismic collapse of a 1960s RC building”,
Journal of Performance of Constructed Facilities, 31(6): 04017111 (2017).
21
22. Maria Gabriella Mulas
Pubblicazioni scientifiche sul crollo di Via
D’Annunzio e del capannone industriale
1. Mulas M.G., Pantalena R., Smerzini C., Coronelli D. “The assessment of an existing RC framed structure: a
case study on a collapsed building”. Proceedings of the 9th International Conference on Structural Dynamics,
EURODYN 2014. Porto, Portugal, 2014, A. Cunha, E. Caetano, P. Ribeiro, G. Müller (eds.).
2. Bamonte P, Mulas M.G., Paolucci R. “Il collasso di un edificio industriale prefabbricato durante il terremoto
del 2012 in Emilia Romagna”. Atti del 20° Congresso CTE, pp. 721-730, 2014.
3. Coronelli D, Mulas M.G. “Testing low strength concrete of collapsed frame buildings”, Atti del Convegno di
Ingegneria Forense IF CRASC 2015, pp. 109-119, 2015.
4. Bamonte P, Mulas M.G., Paolucci R. “The earthquake-induced collapse of an industrial building: structural
issues”, Atti del Convegno di Ingegneria Forense IF CRASC 2015, pp. 557-568, 2015.
22