Recorded Motions of the 6 April 2009 M_w6.3 L'Aquila, Italy, Earthquake and Implications for Building Structural Damage: Overview

Abstract

The normal-faulting earthquake of 6 April 2009 in the Abruzzo Region of central Italy caused heavy losses of life and substantial damage to centuries-old buildings of significant cultural importance and to modern reinforced-concrete-framed buildings with hollow masonry infill walls. Although structural deficiencies were significant and widespread, the study of the characteristics of strong motion data from the heavily affected area indicated that the short duration of strong shaking may have spared many more damaged buildings from collapsing. It is recognized that, with this caveat of short-duration shaking, the infill walls may have played a very important role in preventing further deterioration or collapse of many buildings. It is concluded that better new or retrofit construction practices that include reinforced-concrete shear walls may prove helpful in reducing risks in such seismic areas of Italy, other Mediterranean countries, and even in United States, where there are large inventories of deficient structures.

Spectral-Element Simulations of Seismic Waves Generated by the 2009 L'Aquila Earthquake

“…Moreover, these effects can be intensified and complicated by topographic ridges, which can cause amplifications, reflections, and multipathing (e.g., Lee et al, 2008;). Significant site amplifications have been observed for the 2009 M w 6.3 L'Aquila event in neighboring regions (e.g., Ameri et al, 2009;Bindi et al, 2009;Akinci et al, 2010;Çelebi et al, 2010). At L'Aquila city, for example, based on previous studies (e.g., De Luca et al, 2005), these effects are related to the presence of a basin filled with lacustrine sediments with a maximum depth of 250 m. Central Italy features several other sedimentary basins, and these can have a similar influence on ground motion (e.g., Bindi et al, 2004Bindi et al, , 2009Castro et al, 2004).…”

“…Imaging of the source (Anzidei et al, 2009;Atzori et al, 2009;Cirella et al, , 2012Pino and Di Luccio, 2009;Cheloni et al, 2010;Scognamiglio et al, 2010) highlights a complex rupture history composed of two main slip releases and controlled by spatial variations of material properties along the fault Lucente et al, 2010;Di Stefano, Chiarabba, et al, 2011) as well as temporal variations (Lucente et al, 2010;Zaccarelli et al, 2011). The source characteristics are partly responsible for the southeast directivity (Pino and Di Luccio, 2009;Akinci et al, 2010) and the unusually high levels of strong acceleration recorded close to L'Aquila city Çelebi et al, 2010). We note that all previous source imaging studies have adopted 1D layered seismic wavespeed models for the inversion, even excluding the topography which, however, is relevant in a region like Abruzzo that is crossed by the Apennines.…”

The contribution of seismic data in microzonation studies for downtown L’Aquila

“…The complete collection of L'Aquila sequence strong motion records can be found in the Italian Accelerometric Archive (Working Group ITACA 2010). Some important information on L'Aquila sequence strong motion data can also be found in recently published papers (Ameri et al 2009;Celebi et al 2010). On analyzing strong motion data, a particular care must be put in understanding the presence of effects related to the housing of the instruments.…”

“…Surface geology, characterized by the presence of a sediment-filled alluvial valley, and morphology, with the presence of important variations in topography, also contributed in the distribution of damage and in its spatial variability (Bergamaschi et al 2011). A discussion about damage distribution and its causative effects, along with an analysis of the strong motion data recorded in the epicentral area can be found in recent papers by Tertulliani et al (2010) and Celebi et al (2010).…”

Local variability of the ground shaking during the 2009 L’Aquila earthquake (April 6, 2009—Mw 6.3): the case study of Onna and Monticchio villages

“…During the 2009 sequence a significant role of seismic vulnerability has been observed in many historical centres, with heavy damage and collapses concentrated in the unreinforced masonry buildings including ancient churches (Aydan et al 2009;EERI 2009). The more recent buildings, developed during the last few decades and with the presence of reinforced concrete (RC) and good masonry, in general suffered from slight to moderate damage (Celebi et al 2010).…”