PSI - Issue 44

Giuseppina De Martino et al. / Procedia Structural Integrity 44 (2023) 1800–1807 Giuseppina De Martino et al. / Structural Integrity Procedia 00 (2022) 000–000

1801

2

They caused about 150,000 fatalities, very severe damage to buildings and loss of historical and cultural heritage [Dolce et al. (2021)]. To the tragic balance in terms of fatalities must be added the serious impact of earthquake on the Italian public finances, in terms of both direct (emergency management and reconstruction) and indirect costs (reduction in gross domestic product due to the decline in agricultural and industrial production, social and psychological population assistance costs, etc.). The ICPD (Italian Civil Protection Department) estimated that emergency and reconstruction funds between 1968 and 2016 amount to more than two hundred billion euros (actualized to 2019) mainly due to the earthquakes of 1968 Belice, 1976 Friuli, 1980 Irpinia, 1997 Marche-Umbria, 2009 Abruzzo, 2012 Emilia Romagna and 2016 Central Italy [Dolce et al. (2021)]. The analysis of damage and economic losses induced by several earthquakes cannot be disregarded from their historical contextualization. Post-seismic emergency management and the reconstruction models that have followed over time must be analyzed according to the territorial context and the time the earthquake event occurred. All post earthquake reconstruction models used from the 1968 Belice earthquake to the present (2022) have been based on some criteria that have not changed over time and others that, instead, have evolved to allow for the experience of previous earthquakes and for the improvement of technical and scientific knowledge. For example, the decision making process of the reconstruction of buildings damaged have been refined over time. Among the most debated and most complex aspects in the decision-making process of the repair/reconstruction of buildings damaged by an earthquake, there is certainly the determination of the maximum costs eligible for funding for the repair and, possibly, seismic strengthening of buildings. The 2009 Abruzzo post-earthquake reconstruction process involved two different models in two different phases: the so-called "analytical model" and the "parametric model". The analytical model was adopted in the first phase of reconstruction from 2009 to 2013 for residential buildings geographically distributed outside the historic centers (OHC) of L'Aquila and of the provinces of L'Aquila, Pescara, Chieti and Teramo; the "parametric model” was adopted in the second phase and currently ongoing for the reconstruction of residential buildings located in the historic centers of L'Aquila (IHCUSRA) and the other municipalities in the crater (IHCUSRC). The reconstruction OHC was regulated by Law 77/2009. Its management was entrusted to a proper committee, the so-called “Filiera” (i.e. an Italian word to indicate a supply chain mechanism). From June 2009 to February 2013, more than 19,000 applications for funding were instructed by the Filiera, for a total of 5,775 buildings; this allowed the return to their homes of about 22,000 people already in December 2010, and more than 42,000 in December 2015 [Mannella et al., (2017)]. The procedures envisaged by the analytical model and regulated by OPCMs Nos. 3779, 3790, 3881 and 3820, which appear to have been fully successful about buildings OHC, appeared conversely not immediately and easily extendable to the case of buildings in aggregate (typical of the built environment of historic centers). In line with the reconstruction model used after the 1997 Umbria and Marche earthquake, 2002 Molise earthquake (up to the most recent ones, 2012 Emilia-Romagna earthquake, 2016 Central Italy, and 2017 Ischia Island earthquake) a parametric model was introduced by Law n. 134/2012. It was managed by Special Reconstruction Office of L'Aquila - USRA - for the reconstruction process of buildings IHC of L'Aquila, and the Special Reconstruction Office of the Crater Municipalities - USRC - for the reconstruction process of buildings IHC of other municipalities. Each Office developed a parametric model to manage the reconstruction process and to define the maximum public grant to repair and strengthen the damaged buildings [Fico et al., (2017)]. To date the reconstruction process of IHC residential buildings is still ongoing. At the end of 2019, 3,938 funding requests for repair and strengthening interventions on AMU’s were submitted to USRA (1,581) and USRC (2,357). The Special Offices approved 1,563 funding requests (730 by USRA and 833 by USRC). The paper deals with the reconstruction models adopted OHC and IHC by the two Offices, the analysis of AMU characteristics and usability ratings as well as repair and retrofit cost data obtained by funding requests. Furthermore, a comparison between the repair and retrofit cost data and peculiarities of residential buildings OHC and IHC is herein presented. 2. Reconstruction process inside and outside historical center After L'Aquila 2009 earthquake, in situ inspections of buildings located in 130 municipalities [Dolce and Goretti 2015] were carried out to assess the damage and usability rating of ordinary buildings. The AeDES form [Baggio et al., (2007)] was used to define different usability ratings: i) A – usable; ii) B – usable after short term countermeasures;