The non-smooth contact dynamics method was selected to investigate the damage occurred to typical masonry churches (namely Apennine churches) belonging to Central Italy areas affected by the seismic activity started in 2016. The investigated buildings show discontin-uous dynamics since the optioned method gave the chance to properly model the temples as multi rigid body systems using the Signorini's impenetrability condition and the dry-friction Coulomb's law, achieving a thoughtful response to ground seismic solicitations. The results provided by the assessment grant an overview of the most common damages and failure mechanisms, giving the guidelines to restoration projects that fully respond to structural needs.

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The subject of this work is the Sant'Agostino Sanctuary in Offida (Italy); we investigated both the dynamic behavior and the seismic vulnerability of the complex, used nowadays in its parts as school building, oratory, and church. Offida is in central Italy; the village has been severely damaged by the last seismic events of 2016. The sanctuary was heavily damaged by the earthquake of 24 August 2016. We recurred to finite elements to estimate the vulnerability of the sanctuary and its dynamic response, considering masonry's non-linear behavior by means of proper constitutive assumptions. To estimate how the monastery bears the lateral loads related to the expected demands resulting from seismic actions (N2 method) using non-linear static analysis (Pushover), we recurred to a homogenized material and smeared cracking and crushing constitutive law. As may be remarked by observing buildings that share the same features of the sanctuary and, moreover, by comparing seismic demand vs. capacity, the structure is prone to massive damage leading to collapse. The paper underlines how advanced numerical analysis grants fundamental data on how historical masonry buildings behave under seismic action, providing a method that may easily be implemented at historic monasteries in Europe.

Background:In October 2016, two major earthquakes occurred in Marche region in the Centre of Italy, that resulted in widespread damage. The second one strokes Norcia, Visso, Arquata del Tronto, Accumoli and Amatrice, causing a lot of damages to cultural heritage of the cities of Tolentino, San Severino, Camerino and Ascoli Piceno, where the church ofSanta Maria della Caritàis located.Introduction:The church has high historical, architectural and social value for the city of Ascoli Piceno, because it is the only one that is opened to the devotees all time in the day and night. From the structural point of view, the church has a long and important annex to the north, which was later built with respect to the church, and after the L’Aquila earthquakes (2009) damages, the church was subjected to a retrofit intervention, in order to obtain a better “box-like behavior”.Objective:This paper addresses how the relevant annex influenced the seismic response of this historical complex and how, more generally, this kind of asymmetric mass may affect the behavior of historic churches.Results and Conclusion:The results indicate that the presence of annex plays a significant role in the dynamic response of the church and affects the distribution of damages in the whole building. The results of the seismic simulation agree with the observed damage.

This paper presents a new damage detection index for arched structures, which can easily and quickly provide an estimate of their integrity. The results from eight laboratory tests performed on both reinforced and unreinforced adobe arches are used to define the index. The arches are damaged up to collapse using pseudo-static test cycles carried out by applying progressive controlled displacements at third span. The test records allow to follow the stiffness degradation of each arch by plotting the relative force-displacement curves, as well as to track their frequencies variation during the damage evolution by means of dynamic identification tests performed at the end of each cycle. The new index considers the bending moment as the main cause of damage for the analysed arches; therefore, starting from the bending stiffness, a damage indicator was developed and experimentally validated, as function of the frequency reduction, respect to the undamaged scenario. Finally, the index is also validated for different types of arch collapse mechanisms through Finite Element Modeling.