Cultural Heritage Buildings and the Abruzzo Earthquake: Performance and Post-Earthquake Actions

Abstract

The architectural heritage was seriously hit by the earthquake that occurred on April 6th 2009 in the Abruzzo region, especially considering the effects on a city with the size and with historical and strategic importance as a capital of a region, L’Aquila. The activities to protect that heritage have been centralized in the structure “Protection of Cultural Heritage” at Di.Coma.C. (Command and Control Quarter), managed by the Civil Protection Department. This allowed the cooperation among different involved subjects (Ministry of Cultural Heritage officers, experts on structural engineering from Universities and Fire Brigade teams), with their own specific knowledge. Keystone of the operating process was the standardization of the damage survey and of its immediate and correct interpretation, through dedicated survey forms for churches and palaces. The experience in the field of temporary safety measures was extremely interesting: ideas for engineering the process were developed, in cooperation with the work of the fire brigade men, that are highly experienced technicians in the “emergency” field. Finally, monitoring plans for some important monuments have been set up for the control of the damage progression and the analysis of the structural behavior of buildings after the earthquake and the execution of temporary interventions: two cases (St. Mark Church and the Spanish Fortress) are discussed.

The Dynamic Behavior of the Basilica of San Francesco in Assisi Using Simplified Analytical Models

“…In fact, invasive or strengthening techniques can cause detrimental effects to their seismic behavior due to stiffness incompatibilities (Binda et al 2003). Recent studies emphasize how invasive retrofits on historic masonry structures have played a role in the collapse of the Basilica of Santa Maria Di Collemaggio Arcidiacono et al, 2014), the Basilica of San Bernardino, the Basilica of Santo Domenico, the Basilica of San Eusanio Martire (Lagomarsino et al, 2004;Lagomarsino, 2012), the Basilica (Modena et al, 2010), and the Basilica of Santa Maria Paganica (Carocci et al, 2010) during the 2009 L'Aquila earthquake. All these examples suggest, in a qualitative fashion, that the collapses of these Basilicas were due to incompatibility of modern materials with the existing structures as well as increased seismic loads due to the addition of mass and stiffness to the structure during the restoration.…”

Numerical study on the performance of improved masonry-to-timber connections in traditional masonry buildings

“…/$0 = 9 × (8) 3 = 4.10 × × 7.8 [adapted for use in masonry [13]] (9) where /$ is the projected failure area of a single anchor or group of anchors limited by the edge distance or spacing, as represented in Figure 15, 1 $,/ is the modification factor for anchor groups loaded eccentrically, which is not the case under study so 1 $,/ is equal to 1; 1 +,/ is the modification factor for edge distances less than 1.5 , see equation 10, 1 $,/ is equal to 1.0 when the base material indicates cracking at service loads, which is considered to be case for masonry, and 1 $ ,/ is the modification factor for splitting, equal to 1 in this case.…”

“…On the other hand, a dissipative device to improve the connection of perpendicular walls was recently proposed by Paganoni and D'Ayala [8]. Some examples of traditional and innovative strengthening solutions for connections can be found in [2], [9], [10]. Injected anchors are particularly well suited to repair and strengthen ancient masonry buildings as they allow for an effective connection between perpendicular walls, thus avoiding overturning of walls excited out-of-plane and activating the relatively stable in-plane behaviour of adjacent walls.…”

On the monitoring of historic Anime Sante church damaged by earthquake in L'Aquila

“…The dynamic sensors are distributed inside the church to control the damaged zones, that is, 16 piezo‐electric mono‐directional accelerometers, with nominal sensitivity of 1000 mV/g and frequency interval (±5%) from 0.025 to 800 Hz, and four piezo‐electric tri‐directional accelerometers, with nominal sensitivity of 1000 mV/g and frequency interval (±5%) from 0.5 to 3000 Hz. This kind of accelerometers, as well as the choice of sensitivity value, is widely used for monitoring historic structures . The dynamic monitoring equipment ensures the control of ambient—as well as man‐induced vibrations on the structure and on safety measures—the latter due to the installation and control of safety measures, which is still in progress.…”

“…The structural response (output) has been evaluated with respect to vibrations of officially recorded earthquakes, before and after safety interventions (i.e. cables and FRP belts around the church ).…”