Shaking table testing of a full-prefabricated three-storey timber framed building

Shake table tests were carried out on a 7m x 5m three-storey timber light-frame building (7.5 m height) at the TreesLab laboratory (Eucentre) in Pavia. The aim of the research was to evaluate the seismic behaviour of a typical Italian prefabricated timber building and to study the interaction between the individual structural components tested in quasi-static manner in a previous experimental study. The 1979 Montenegro Earthquake ground motion, recorded at the Ulcinj-Hotel Albatros station, was selected as the ground motion for seismic tests. The maximum peak ground acceleration was scaled to 0.07g, 0.27g, 0.5g. 0,7g and 1g in order to evaluate the building’s performance at different levels of seismic input. More than 100 instruments were used to monitor the behaviour of the building during seismic tests measuring acceleration, displacement and forces. The visual inspection shows that the building did not show any damage during all seismic tests. However the data analysis (dynamic identification, capacity spectrum, inter-storey drift) confirm that during the 1.00 g test the structure went beyond its linear elastic limit. The results obtained from this experimental study suggest that the design hypotheses commonly adopted in practice for seismic analysis (e.g. in terms of force distributions between the walls, and also the behaviour factor q) are not always consistent with the real behaviour of timber-frame multi-storey buildings, and should be backed by more accurate knowledge of the contributions of the individual structural components.