The 2009 L’Aquila earthquake left approximately 67,000 homeless people. The earthquake severely damaged facilities, structures, and infrastructure of L’Aquila town, the capital of Abruzzo region, as well as 56 other municipalities in the so-called “crater”. The resident population in the crater area at the time of the earthquake included 68,503 inhabitants in the city of L’Aquila and 71,081 in other municipalities of the crater, yielding a total of 139,584 inhabitants. Several solutions were adopted to host homeless people in the immediate emergency phase; then, temporary accommodations were built to host people up to the completion of the reconstruction process. This paper analyzes the timeline by which people who lived in L’Aquila city at the time of earthquake was enabled to return to their houses, either repaired and strengthened or rebuilt. In particular, this analysis covers the first phase of the reconstruction process as well as its second phase, which is currently still ongoing in L’Aquila’s historical centers. The trend of a population returning home discussed herein has been determined based on data collected from different databases given by several institutions engaged in the emergency and reconstruction phases; this allowed an estimation of the number of people returned to their homes over time.

A model is presented for forecasting the seismic vulnerability and probability of damage of ordinary building types, as a function of the local macroseismic intensity or correlated parameters of the ground motion. The conventional definitions of damage degrees and vulnerability classes of the building types have been assumed according to the EMS98 macroseismic scale. The model allows damage scenarios to be evaluated in selected areas where an inventory of the buildings, containing at least some qualitative information is available, in order to recognize, for the different types, the corresponding vulnerability class or at least the probability of membership to the vulnerability classes. The epistemic uncertainty of the qualitative definitions suggested by the scale for frequencies of damage is taken into account through the formalizing of the imprecise probabilities, i.e. through convex sets of possible probability distributions on the discrete space of the damage degrees, with particular reference to their description by means of random sets, both non-consonant and consonant (fuzzy sets). It is thus possible to obtain upper/lower bounds of the expectation of interesting functions of the damage degrees (e.g. number of victims, unusable buildings, and collapsed buildings). The model has been applied to the entire area of the Abruzzo Region (Central Italy), using the inventory of buildings recorded by the National Statistics Agency. Some comparisons are given between the expected damage and that observed after the strong earthquake that in April 2009 struck a more restricted zone of the region (the town of L'Aquila and surrounding countryside).

The planning of energy saving and structural retrofit interventions on masonry buildings are usually two separate projects; combined interventions are rare. Solutions tackling both aspects can reduce total refurbishment costs and improve global building performance. However, heavy interventions on the envelope have to be carefully designed in order to improve both seismic and energy performance whilst mitigating environmental impact. National energy saving regulations are generally less strict for historical buildings, making this category of buildings very interesting not only because of their widespread diffusion across Italy but also because of the possibility of planning interventions that will allow significant improvements by combining building efficiency and safety. This research looks at these aspects and proposes new methods for refurbishing masonry buildings combining seismic improvements and energy saving interventions. Among those mostly commonly applied on masonry buildings in Italy, and described in this paper, are various combined retrofit interventions, and we report the results of these interventions on thermal transmittance reduction and global costs.

The seismic sequences occurred in Italy during the last decades confirmed the vulnerability of historical centres and the need for novel procedures aimed at preserving the cultural heritage and mitigating the structural risk. Building conservation and safeguard require a multidisciplinary approach, so that an accurate assessment of buildings conditions, both conservative and structural in nature, can be accomplished; as a result, potential risk factors and the associated interventions to increase the resilience of sites and historic buildings can be successfully identified. Herein, an insight on the technical literature offers some reflections about a reliable framework for conservation plans that could comply with the current knowledge and technology, and therefore potentially defined proactive. The opportunities given by the integration of information systems and structural monitoring techniques are analysed in the light of a SWOT analysis able to support a rational approach to the preservation of historical centres. The proposed SWOT matrix is the result of an interdisciplinary effort and reflects the key features of a real case, paradigmatic of many historical centres of the Abruzzi Region. In such a perspective, this study represents a step forward an effective and rational approach to the structural maintenance and preservation of historical centres.

The aim of this research is to evaluate the effectiveness of a seismic retrofit technique that involves the introduction of energy dissipation devices properly connected to an existing structure through a system of cables and levers, which are employed to amplify total or inter-story drift at device end. One of the main topics related to the introduction of energy dissipation devices, lies in the choice of their optimal setting within the structure to maximize the effectiveness without producing functionality limitations. The achievement of these objectives is, therefore, linked, regardless of the type adopted, to the amount of energy dissipated in each cycle, directly proportional to the displacement magnitude to which the device is subject. Many configurations proposed in the literature and currently adopted in professional practice provide additional dissipation systems variously connected to braces installed inside the structural frame and, therefore, able to exploit the inter-story drift produced by seismic input. The proposed system exploits top displacements of the structure with respect to the foundation level, transferred to the device through a system of cables properly configured and amplified with leverage. This paper represents the first step of the research, in which simple single degree of freedom (SDOF) or two degrees of freedom (2-DOF) models are taken into account to evaluate the effects of the introduction of the proposed system in terms of reducing the seismic demand on the structure, proceeding to a parametric analysis to obtain initial indications for the design of the system in relation to the geometric and inertial characteristics of the original structure.

The design and erection of new buildings and structures are today driven by strict requirements in terms of sustainability and circular economy, but they represent only a minor part of the built heritage. Hence, it is clear that the maintenance and upgrading of existing buildings play a key role in the achievement of the objectives identified in many developed countries, so that the regeneration of buildings represents the core of many real-world projects. Regenerating existing buildings requires the achievement of modern reuse requirements, the modulation of structural and energy performance, but primarily the fulfilment of many objectives associated with extrinsic (urban planning) and intrinsic (architectural, structural and technological) features. In the present paper, a discussion on the role and potentialities of exoskeletons is reported with the objective of supporting decision makers in resolving the issues associated with the need to improve the overall performance of existing buildings in urban areas. In particular, relevant aspects associated with the conceptual design of multifunctional exoskeletons are reviewed in order to chart a rational course to perform multiscale and interdisciplinary design methodologies.