Publication Date:
2017-04-04
Description:
Earthquake-rotated objects (EROs) have been observed and
described for centuries (e.g., Hoffmann, 1838; Mallet, 1862;
Reid, 1910). Several theories about the rotating mechanisms
have been developed. Kozák (2006) classified rotating effects
as those caused by a deviation between the projection of
the center of gravity into the contact plane and the point
of strongest adhesion (Rot1) and those due to subsequent
arrival of ground-motion phases from different directions
(Rot2).
The EROs found in the literature include parts of buildings,
such as chimneys, monuments, tombstones, and columns,
often described with great care and in detail by early earthquake
reports (Mallet, 1862) or still accessible (Boschi et al.,
1995). However, in most cases rotational effects are observed
on vertically oriented objects such as gravestones, tall monuments,
and single columns (Kozák, 2009). Although earthquake-
toppled objects (ETOs) allow the determination of
minimum ground-motion thresholds which caused the toppling
(Kamai and Hatzor 2008; Hinzen, 2010, 2012), EROs
and earthquake-deformed objects (EDOs) present the chance
to make a more detailed back calculation of the causative
ground motion (Yegian et al., 1994; Lee et al., 2009; Hinzen
et al., 2010; Hough et al., 2012).
Numerous EROs were observed and documented during
the 2009 L’Aquila earthquake in central Italy. Cucci and
Tertulliani (2011) and Castellano et al. (2012) showed a correlation
between the occurrence of EROs in the mesoseismal
zone, the fault orientation, and the site conditions. Some of
the simply structured and vertically oriented objects mapped
by Cucci et al. (2011) and Cucci and Tertulliani (2011) offer
the opportunity to use local strong-motion records to test different
hypotheses about the mechanisms that caused the rotation.
A main question in this context is whether near-field
rotational components of ground motion are necessary to rotate
the studied objects or whether 3D purely translational
ground motions are sufficient to explain the observations.
In this study, we use discrete-element models of EROs that
are based on laser scans to study the dynamic behavior of
the EROs and rotations induced by translation ground motions
and uneven foundations.
Description:
Published
Description:
745-751
Description:
3T. Pericolosità sismica e contributo alla definizione del rischio
Description:
JCR Journal
Description:
restricted
Keywords:
earthquake rotations
;
L'Aquila 2009 earthquake
;
04. Solid Earth::04.06. Seismology::04.06.99. General or miscellaneous
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Permalink
