Seismic Interaction of timber roofs and supporting walls

Damage or collapse of traditional timber roof structures often occurs during earthquakes, with possible extension to the underlying masonry structure. Several cases of damage involving roof structures have been observed during recent earthquakes in Italy, particularly at L’Aquila in 2009 and in the Emilia region in 2012, with particularly devastating effects on churches. Collapse of the roof was generally due to loss of support, which could derive from lack of local restraint, with the truss ends falling off the wall, or more often from deterioration or collapse of the supporting wall. In the work proposed here, the limit equilibrium of the truss-wall system is analysed, pointing out the main conditioning parameters of the two components. The aim is to develop synthetic rules for visual inspection based vulnerability assessment.