SEISMIC RISK REDUCTION FOR ARCHITECTURAL HERITAGE
Modern and ancient architecture are part of the cultural heritage of a community and they are remarkably important in order to preserve a country`s identity. Policies regarding cultural heritage in a nation aim at the acknowledgement, conservation, sustainability and restoration of it as evidence of national culture for present and future generations. Nevertheless, this legacy is threatened by the risk of being lost, and there are different threats either anthropic (human-caused direct damage, fire, collapse due to lack of planning and retrofitting, inadequate environmental management) or natural (earthquakes, climate change, landslides, hurricanes, volcanic eruptions, etc.) that can cause the loss or damage of architectural heritage. Risk management of cultural heritage is a worldwide concern, and as a result of the increase of natural disasters in recent years in the world, the international scientific community and international organizations such as UNESCO are working to confront this problem, making different sectors aware of the importance of dealing with this problem and establishing appropriate risk management policies for cultural heritage as an important tool for sustainable development in a nation. Considering this important issue, the main goal of this article is studying seismic risk of architectural heritage and prevention policies. Seismic risk is a topic of interest in many countries, especially in Latin-American, middle-eastern and far eastern countries such as Japan. Studying seismicity as well as the actual situation of cultural heritage in Japan and Colombia, this article shows preliminary results of a research project on comparing the two countries in terms of retrofitting methodologies and risk management policies to protect architecture that is considered cultural heritage, which is important to reduce its vulnerability. This article also includes some considerations about laws enforced in both Japan and Colombia to protect architectural heritage in high seismic hazard regions and their prevention strategies.
Keywords: Seismic risk, Architectural heritage, Colombia, Japan, Retrofitting methodologies
Riduzione della vulnerabilità di strutture prefabbricate
The paper describes a research focused on low-cost anti-seismic devices to be installed on precast buildings. This work consists in studying the behaviour of two-dimensional precast RC frames, equipped with dissipative devices placed on beam-column joints and at the base of the columns. The evaluation of the performance capabilities before and after the insertion of the devices is conducted. This system fully satisfies the requirements in terms of easiness of installation and costs reduction.
THE INVOLVEMENT OF ARCHITECTURE IN SEISMIC DESIGN
Almost every progress in science has been paid for by a sacrifice, for almost every new intellectual achievement previous positions and conceptions had to be given up.
Werner Heisenberg, Nobel Prize for Physics, 1932.
RICERCA DI SISTEMI DI PROTEZIONE APPROPRIATI PER SCHEMI PREFABBRICATI
The paper presents the layout and the first development of a research targeted on the study of seismic protection devices at low cost to be inserted in the joints of precast concrete building systems. The first part of the work is targeted to the classification of devices, with particular attention to construction details, the compatibility of seismic code and the costs of production. The second part of the work is targeted to the identification of technological strategies that can improve the expected seismic performance to prefabricated systems . With reference to a case study, was established the increase of the seismic capacity of structural precast systems and the reduction of cost construction of the elements in order to offset the cost of the devices.
Keywords : precast building, joints beam –column , seismic capacity.
The underlying concepts of earthquake engineering have evolved substantially over recent years. The objectives have become more ambitious and procedures for building design have become more complex. Countries subject to seismic risk have updated their standards: some to a considerable extent, others less so. In any case, greater attention is now focused directly on the prevention of building collapse by controlling the post-elastic behaviour that constructions bring into play to defend themselves when attacked by violent earthquakes. Consequently, design requirements are no longer met by performing only traditional resistance checks on assigned forces systems, because the checks must now refer to requirements with predefined performance criteria.
EVENTI CATASTROFICI LUNGO LE PENDICI ANDINE DELLA CORDIGLIERA CENTRALE
In Colombia in the late twentieth century there were two events that we call ''catastrophic'' when compared with many other cases too easily regarded as ''exceptional.'' These two events occurred in the center of the country in the region of Tolima, with the eruption of the volcano Nevado Ruiz and the consequent destruction of the town of Armero (1985) and again with the earthquake, January 1999, in Armenia has destroyed the capital Department of Quindio. The paper will analyze these two events have been an important development opportunity for the affected regions.
ADEGUAMENTO E MIGLIORAMENTO SISMICO DELLE STRUTTURE OSPEDALIERE
Hospital has always played a crucial role because it is an emergency strategic building for the ordinary and even more in case of exceptional events such as earthquakes. Apart from the few recent buildings designed and built according to NTC (2008), design and intervention methods of existing buildings are going to be investigated with more and more attention. In the context of many historical cases, which have indicated the high vulnerability of these buildings, and in relation to the mandatory provisions of actual codes and regulations, this article introduces the problem outlining the regulatory system, then focuses on how to approach the issue of checking existing structures, and finally outlines the main mode of intervention, improvement or repair of existing hospitals.
SEISMIC ISOLATION: WHY, WHERE, WHEN
Seismic isolation is coming out from its pioneer period and now it is on the way to become a popular system for the seismic protection of ordinary structures. The criteria concerning the architectural morphology, the selection of the structural configurations and other design options of seismic isolated buildings shall be discussed to popularise its use, to improve the effectiveness of ordinary applications, to cut down the construction costs and to open the way to new and wide applications. Moreover, the experts should emphasise the higher reliability of the design procedures commonly used for fixed-base structures, when applied to isolated structures. The target is to avoid that new applications are discouraged by unnecessary and complex analyses required by specific codes. Taking the opportunity of some demonstrative initiatives promoted by the local Government of the Umbria Region after the seismic ''swarm'' that struck central Italy in 1997 and 1998, this papers deals with practical topics concerning the application of seismic isolation to ordinary residential and commercial buildings.
SEISMIC ISOLATION AND STRUCTURAL CONFIGURATIONS
Seismic isolation is coming out from its pioneer period and now it is on the way to become a popular system for the seismic protection of ordinary structures. The criteria concerning the architectural morphology, the selection of the structural configurations and other design options of seismic isolated buildings shall be discussed to popularise its use, improve the effectiveness of ordinary applications, cut down the construction costs and open the way to new applications. Moreover, the higher reliability of the usual design procedures when they are applied to isolated structures rather than to fixed-base structures must be emphasised. The target is to avoid that new applications are discouraged by unnecessary and complex analyses required by specific codes. Taking the opportunity of some demonstrative initiatives promoted by the local Government of the Umbria Region after the seismic swarm that struck central Italy in 1997 and 1998, this papers deals with practical subjects concerning the application of seismic isolation.
BASE ISOLATION AND STRUCTURAL CONFIGURATION
This paper illustrates the design criteria that guided the architectural and structural designs of the base isolated buildings of the new Emergency Management Centre of Foligno (Umbria).
A special attention was paid to the architectural shapes and structural configurations. They have been selected in order to maximize the effectiveness of the seismic protection that can
be achieved through the Base Isolation approach. The high potentiality of the Base Isolation option is also illustrated showing its capacity to solve the design problems that arose when,
at the end of a first structural design phase, the new Italian seismic code attributed Foligno to a higher level of seismic risk. The construction works of the buildings are now in progress.
Non si può sfidare il terremoto a braccio di ferro
Il terremoto è un evento naturale imprevedibile; nelle sue manifestazioni più violente colpisce con una intensità tale da impegnare le capacità di risposta dei materiali da costruzione oltre i loro limiti di resistenza.
L'EVOLUZIONE DELL'INGEGNERIA SISMICA IN ITALIA
Il ritardo nella divulgazione e nell'accettazione delle più avanzate concezioni progettuali antisismiche ha provocato un effetto di deriva che sta producendo un preoccupante distacco fra i risultati delle ricerche tecnico-scientifiche e la loro applicazione nella pratica realizzativa corrente.
LA MURATURA ISOLATA ALLA BASE di Alberto Parducci
Grazie ai nuovi metodi di protezione sismica, la muratura è da considerare oggi come un normale sistema costruttivo capace di resistere ai terremoti senza particolari problemi. La muratura possiede un'ampia varietà di caratteristiche; alcune di esse non emergevano in una concezione convenzionale del problema sismico basata sulla sola ricerca di ''resistenza''. Altri aspetti la rendono invece adatta ad essere utilizzata utilmente se si applicano alcune tecniche innovative, come l'Isolamento alla Base (Base Isolation). L'abbinamento sfrutta bene la combinazione delle prestazioni dei due sistemi ed assicura livelli di sicurezza non inferiori a quelli degli altri materiali oggi più usati. E' perciò possibile, anche nelle zone a rischio sismico, costruire edifici sicuri senza rinunciare alle qualità estetiche, tecnologiche e di durabilità di questo antico sistema costruttivo.
NUOVI ORIZZONTI PER UN'ARCHITETTURA ANTISISMICA - Alberto Parducci
Si esaminano alcuni problemi riguardanti il coinvolgimento dell'Architettura per quanto riguarda il contributo compositivo nel progetto delle opere da realizzare nelle zone ad elevato rischio sismico. L'argomento è riferito alla capacità di risposta delle strutture nei confronti dei terremoti di grande violenza, quando l'intensità delle scosse raggiunge livelli tali da superare i normali limiti di resistenza dei materiali. In tal caso, la sola ricerca di un'adeguata ''resistenza'', intesa in senso tradizionale, non è più un obiettivo sufficiente. In aggiunta alle tecniche del Capacity Design [49,50] basate sul controllo dell'energia dissipata nei danneggiamenti, gli obiettivi diventano: individuare sistemi alternativi adeguati; ottimizzarne l'impiego per minimizzare i danni alle strutture ed alle parti non strutturali, ridurre, o possibilmente eliminare, le perdite dei valori contenuti; ridurre i costi per la riparazione delle costruzioni danneggiate.
IL CENTRO REGIONALE UMBRO DELLA PROTEZIONE CIVILE
Già prima della crisi sismica del 1997 la Regione Umbria, con la L.R. 26/88, aveva programmato la realizzazione di un Centro Regionale delle attività per la sicurezza civile ed ambientale.