GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 2.2 GNGTS 2023 These structures, after 13 years, are still widely used and they are going to require maintenance interventions to preserve their functionality. This need was made evident also by some recent events due the collapse of some balconies. After those occurrences, various diagnostic campaigns were carried out to define the mechanical properties of construction materials, the state of consistency of connections and the design coherence of the construction details. Present research goal The assessment of structural vulnerability of timber structures is a rather complex task, because of the material diversity and high susceptibility to different environmental risks, due to its organic nature, compared to other construction materials such as masonry (Shabani et al., 2021). In this case, one of the most dangerous factors to take into account is in fact represented by the high moisture level in primary timber structural elements, and possible consequences on mechanical performances . The Eurocode 8-3 (2004) requires, as input data for the estimation of seismic vulnerability in existing structures, many informative parameters, which mostly derive from detailed construction drawings analyses, in-situ inspections, and destructive/ non-destructive test methods. Such a reference procedure, while structurally sound and exhaustive, is really complex and burdensome, and thus difficult to apply for the entire real estate assets and seismic analysis. It is in far also important to consider that all these periodic diagnostic controls and maintenance interventions are carried out by the city management office. Due to the aforementioned needs, the main aim of present research is to assess possible procedural methodological steps towards the rapid characterization of actual mechanical properties and load-bearing capacities for seismic vulnerability analyses and retrofitting purposes. Establishing this kind of methodology would be particularly important to handle this building asset, due to the consequent improvement of its response to seismic hazard, but also its durability and energy performances. Methodology The proposed methodology exploits the modularity of selected timber structures, and maximizes the potential of monitoring tools for vulnerability assessment. Although being very numerous, these structures are characterized by two different construction types only (namely CLT and light-frame systems) and have been constructed by repeating a basic module from each different manufacturer. Such an operative configuration supports the possibility to deeply investigate (in accordance with provisions of EC 8-3 and also more accurate calculations methods) just one case-study, "reference" building for each producer and focus on: i) the mechanical and load-bearing features of its