Carpentry joints, transmitting forces between timber members by direct contact and friction, were the key-elements of traditional timber construction. Often, such joints were reinforced with metal devices with the aim at avoiding disassembly under exceptional, but undefined and not quantified, loading conditions. Currently, interventions performed to improve carpentry joints are still largely based on empirical state-of-practice schemes, or on simplified assumptions on their behaviour, without explicit reference to seismic conditions. The elastic and post-elastic behaviour of the most widely adopted joints for monotonic and cyclic load has been the object of an extended research program. Results have permitted to define general criteria for the seismic improvement or strengthening of these connections.
timber structures
Concezione strutturale e risposta sismica delle strutture lignee di copertura
In view of assessing the seismic vulnerability of timber roof structures, it is necessary to define evaluation criteria for the various elements and features that influence the structural response. Ths work focuses on the structural concept, particularly interesting because of the numerous existing solutions; indeed, these structures, originally conceived for vertical loads, may be more or less apt to respond to seismic action. With the classic tools of modal and response spectrum analysis the effect of the structural concept has been investigated, in order to define a basis for classification criteria. The aspects that appeared to affect positively the seismic response are a suitable association of the design parameters, according to the traditional construction practice, and the effectiveness of the connections that realize the threedimensionality of the structure.
This paper is available in Italian only.