THE INVOLVEMENT OF ARCHITECTURE IN SEISMIC DESIGN
Base Isolation in Italy before and after the 2009 Abruzzo earthquake
Alberto Parducci. University of Perugia
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.
There are now two explicitly expressed performance objectives. The first is an ethical act, aimed at preventing those disastrous collapses which can injure or kill people. The second is an economic objective, aimed at reducing building and repair costs in the event of damage, i.e. aiming for optimal use of available resources. The two objectives are a clear reference to new earthquake engineering concepts which can only be achieved with the compliance of all those who design and manufacture buildings, especially the ordinary type, because these are where most of those exposed to earthquake consequences are to be found. Thus it is the duty of both the engineering and the architectural (now being offered new openings) sectors to address these problems and suggest new design prototypes.
When such transformations occur, it is not unusual to find that previously neglected problems actually become important. In a complex context like seismic design, modification of reference standards easily begins to challenge consolidated practice. The validity of these practices, however, must be assessed in the light of new knowledge.
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