Study on the seismic behaviour of building inter-story collisions in band configuration

In relation to a specific case study on the seismic vulnerability of a large building in Lisbon, located in a street front, with separation joints to the adjacent buildings of about 10mm, an analysis was conducted concerning the seismic impact on the overall safety of the structure and its different components. This analysis was driven by the absence of sufficiently wide joints to accommodate the displacements that buildings undergo during seismic events. The study revealed that the energy mobilized by the collision between adjacent buildings causes very significant increases in the structural stresses, compared to those resulting from the analysis of the same buildings considered as if they were isolated, that is, without restrictions to horizontal displacements. The information obtained is of great relevance and highlights the need to study the dimensions of “seismic” separation joints between adjacent buildings in new constructions located in bands and blocks. On the other hand, the results obtained confirm there are increased risks of collapses or profound damages to existing buildings, especially of medium and large sizes, located in urban bands and blocks.