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“From Material to Structure”
MECHANICAL BEHAVIOUR AND FAILURES OF THE TIMBER STRUCTURES
The attention of the Scholars and of the Practitioners dealing
with ancient timber architectural structures has been, up to a decade
ago or so, put more on the wood as building material and less on
the structural systems. The action of the biologic factors and the
influence of moisture, by instance, have been deeply investigated
in the laboratory and on the construction but very little has been
made to study the structural systems, their behaviour in the short
and long term, the typical failures when they are solicited by the
“actions”, i.e. own weight, snow, wind, earthquake,
thermal fluctuations, settlements of the supports etc.
The previous approach led to negative judgements on the members
the material of which was affected by the said factors and automatically
to their replacement.
The timber structural systems behave, react and fail in a peculiar
way due the characteristics of the wood. The knowledge on these
topics is essential both by a theoretical and technical point of
view as well by a practical one, specially when planning the strengthening
of the ancient structures of the monumental buildings or of the
ancient timber architectures, which require a quite conservative
approach and , with a few exceptions, refuse – reed: do not
need - deep alterations or replacements.
The Symposium of the 16th ICOMOS Wood International Committee,
toned to 40th ICOMOS Anniversary celebrated with the Exhibition
in Milan, February 2007, on the theme “From Restoration to
Conservation”, is planned to mark the passage from the studies
on the materials to the more general ones on the structural systems;
the aim is to convey experiences and studies on this topic, improve
the methodologies on the appraisal of the ancient timber structures
and to document, in the Countries of the Members, single case studies.
This can lead to an international paradigmatic knowledge on the
matter to be used to recognise, in the practice, the different kinds
of failure also allowing to start a first hypothetical assessment
of the causes, this way encouraging the elaboration of methodologies
on the appraisal of the structures.
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