The L'Aquila Earthquake, April 6th, 2009: A review of seismic damage mechanisms (original) (raw)
Related papers
L’Aquila Earthquake April 6th, 2009: the Damage Assessment Methodologies
Different Methodologies were adopted during the field investigations and the assessment of damage in structures following the Abruzzo (Italy) Earthquake of the 6th April 2009. The scope of the paper is to review the different methodologies adopted by the COST Action C26 Field Investigation Team, and the methodologies considered by the EEFIT Team in the field assignments conducted in the aftermath of the earthquake. The COST C26 team based the assignment on a number of methodologies: the AeDES (AeDES & AeDES Modified) and the MEDEA, used by the Italian Civil Protection for Masonry and Reinforced Con-crete structures; the EEFIT team methodology included the general observations, the rapid survey using EMS-98, and the detailed survey. The aim of the paper is to review the methods, assess the type and extent of data collected and the scale considered, and analyse each methodology with respect to the scope of the tasks undertaken. A critical assessment of the methods, is presented with r...
Structural damages of L’Aquila (Italy) earthquake
Structural damages of L’Aquila (Italy) earthquake
On 6 April 2009 an earthquake of magnitude 6.3 occurred in L'Aquila city, Italy. In the city center and surrounding villages many masonry and reinforced concrete (RC) buildings were heavily damaged or collapsed. After the earthquake, the inspection carried out in the region provided relevant results concerning the quality of the materials, method of construction and the performance of the structures. The region was initially inhabited in the 13th century and has many historic structures. The main structural materials are unreinforced masonry (URM) composed of rubble stone, brick, and hollow clay tile. Masonry units suffered the worst damage. Wood flooring systems and corrugated steel roofs are common in URM buildings. Moreover, unconfined gable walls, excessive wall thicknesses without connection with each other are among the most common deficiencies of poorly constructed masonry structures. These walls caused an increase in earthquake loads. The quality of the materials and the construction were not in accordance with the standards. On the other hand, several modern, non-ductile concrete frame buildings have collapsed. Poor concrete quality and poor reinforcement detailing caused damage in reinforced concrete structures. Furthermore, many structural deficiencies such as non-ductile detailing, strong beams-weak columns and were commonly observed. In this paper, reasons why the buildings were damaged in the 6 April 2009 earthquake in L'Aquila, Italy are given. Some suggestions are made to prevent such disasters in the future.
Site effects in the urban area of L’Aquila damaged by the April 6, 2009 earthquake
Earthquake-Soil Interaction, 2014
This paper presents the results of numerical analyses carried out to assess the different seismic response of two sites in the urban area of L'Aquila (Italy), selected as representative of typical subsoil conditions in the old city centre and in the recently developed suburban Pettino district. Both areas were severely damaged by the April 6, 2009 earthquake. The geotechnical model of the subsoil at each of the two sites and the related parameters, defined based on accurate site investigations, are described. The comparison of results of seismic response analyses at the two sites, consistent with strong motion recordings of the April 6, 2009 main shock, confirms that site effects due to different subsoil conditions played an important role in the observed non-uniform damage distribution. Particularly in the city centre, characterized by an inversion of the shear wave velocity V S with depth, the simplified approach based on elastic response spectra defined according to ground type (V S,30) of the Italian building code tends to underestimate the seismic action and should be used with caution.
Study of vulnerability and damage: the case study ofCastelnuovo after L’Aquila earthquake (Italy)
2012
After the L’Aquila earthquake (04/06/2009), the authors surveyed the building stock of Castelnuovo, a hamlet in the San Pio delle Camere Municipality (L’Aquila). The macroseismic effects reached intensity 9.5 (MCS scale) at Castelnuovo. The shaking caused collapse of 50% of the whole built that includes 102 aggregates and 324 structural units. First of all a brief description of the methodology (with reference to EMS-98 classification) used in the surveys are presented. Then, the main results of the study, in terms of structural typologies and analysis of vulnerability and damage, are defined. By means of the analysis of vulnerability and the geology characteristics of soil, an evaluation of the damage is proposed. Finally in the paper local seismic responses of masonry building aggregates are evaluated: the main results in terms of qualitative classification of out-of-plane mechanisms for the panels are discussed.
Damage Probability Matrices for eight historic centers after the 2009 L'Aquila earthquake
2017
In this paper, the results of a damage reconnaissance activity carried out on eight minor historic centers of Abruzzi after the 6.3 Mw L’Aquila earthquake, occurred on the 6 th of April 2009 in the central area of Italy, is presented. In the first part, minor historic centers belonging to the region interested by the earthquake are described. The main morphological features of these centers, to be ascribed to an historical urban development often carried out according to extemporaneous logics, are discussed. Moreover, the main construction typologies are presented: these are made of poor masonry buildings with many fragility sources and are the result of several transformations and stratifications carried out since the medieval age in order to comply with inhabitants needs, but, mostly, not with structural/seismic matters. The second part of the paper is focused on the occurred damage scenarios. The most frequent failure mechanisms of macroelements are shown and the observed damage ...
Earthquake Resistant Engineering Structures IX, 2013
The quantitative measure of seismic vulnerability is a necessary requirement for prevention and for an optimal emergency management. Before L'Aquila's earthquake in 2009, the National Civil Protection, in collaboration with the University of L'Aquila, developed a model (Beolchini, "Definition of an indicator of urban vulnerability" (2003)) to evaluate the criticality seismic of urban centers by using a multidisciplinary approach. The study has led to the definition of an urban vulnerability index, that allows to identify the most critical urban centers and the problematic elements, in order to establish a hierarchy for preventative measures and for an efficient emergency management (Calvi et al. "Development of seismic vulnerability assessment methodologies over the past 30 years" (2006). One of the features of this evaluation is that it allows a simultaneous analysis of the multiple factors involved in risk assessment (Ferlito and Pizza "Modello di vulnerabilità di un centro urbano. Metodologia per la valutazione speditiva della vulnerabilità della viabilità d'emergenza" (2011); Ferlito et al. "Danger treblement de terre et mesure du risque à L'Aquila" (2010)). After the seismic event occurred, same tests have been done to verify the validity of the model on the part of buildings, by comparing the criticality evaluated and damage suffered by the buildings, taking into account the local effects resulting from operations of microzonation. The seismic vulnerability
Assessment of Post-Earthquake Damage: St. Salvatore Church in Acquapagana, Central Italy
Buildings, 2018
This article proposes a multidisciplinary approach for the assessment of seismic damage from the perspective of conservation and prevention. A comparison of the state of damage has been carried out in a case study, St. Salvatore church in Acquapagana (MC), as an example of church, which underwent two important seismic events in the Central Italy area, the 1997 and the 2016 earthquakes. The comparison of the state of damage passes through the following stages: (a) the territorial seismic overview; (b) the historical description and material analysis; (c) the identification of macro-elements with activated damage mechanisms; (d) the comparison between the two seismic events both from a territorial-and building-scale perspective. This work puts together the archived and the on-site survey data with those elaborated starting from seismogenic information, available from the National Seismological Institute, and it provides a strategy also for other similar conditions. This work is to be considered a contribution to a wider study that could be carried out in the areas hit by the 2016 earthquake. It could also represent a way to collect documentation in the post-earthquake phase, improving the effectiveness of procedures currently applied to the first level of damage assessment.
Engineering Geology for Society and Territory - Volume 5, 2015
An extensive geological, geotechnical and geophysical investigation was performed in L'Aquila city centre to restore Palazzo Centi, a historical building, damaged by the April 6, 2009 L'Aquila earthquake. This site investigation consisted of punctual and linear tests that allowed to define a detailed 3D model of the subsoil, irregularly affected by some peculiar conditions and characterized by low and variable values of the shear wave velocity V S in the near surface volume. In particular, the variable thickness of the upper fine-grained residual soils probably determined different ground motion amplifications during the main shock.