Search results for "Earthquake"
showing 10 items of 174 documents
Tecniche costruttive antisismiche in Calabria tra la fine dell'Ottocento e l'inizio del Novecento,
2016
La presente memoria intende indagare lo sviluppo delle costruzioni antisismiche in Calabria in un periodo compreso tra gli anni Ottanta dell'Ottocento e i primi anni del Novecento. Lo studio è incentrato sulle tecniche costruttive adottate nelle ricostruzioni post-terremoto realizzate in un periodo immediatamente antecedente il sisma che colpì Messina e Reggio Calabria nel 1908, dopo il quale si registra un progressiva affermazione della tecnologia del cemento armato. In questo arco cronologico si assiste a un notevole sviluppo degli studi nel campo della costruzione antisismica, con una prevalente riproposizione di sistemi costruttivi tradizionali e con le prime sperimentazioni sul cemento…
Generation of Earth's early continents from a relatively cool Archean mantle
2019
This research has been supported by DFG grant, SPP 1833 Building a Habitable Earth and MAGMA Consolidator Grant (ERC project #71143). Several lines of evidence suggest that the Archean (4.0 2.5 Ga) mantle was hotter than today's potential temperature (TP) of 1350 ° C. However, the magnitude of such difference is poorly constrained, with TP estimation spanning from 1500 ° C to 1600 ° C during the Meso‐Archean (3.2‐2.8 Ga). Such differences have major implications for the interpreted mechanisms of continental crust generation on the early Earth, as their efficacy is highly sensitive to the TP. Here, we integrate petrological modeling with thermomechanical simulations to understand the dynami…
Gibellina City of Art
2018
The earthquake that hit Western Sicily in 1968 destroyed, among others, the town of Gibellina. Back then, the town was abandoned and a new city was built ex novo at a distance of eighteen kilometres from the original site. The ex novo foundation of a new city requires the interaction of two fundamental components: one characterised by a physical-formal nature, related to urban layout and architectural characterisations, and the other related to socio-cultural issues concerning the relationships between citizens and their city. If the rst component might be dealt with by means of theories and techniques from architectural and urban disciplines, how is it possible to deal with the even more i…
Modal Analysis of a Reinforced Concrete Frame in Various States of Damage
2005
The purpose of this paper is to report selected results of an experiment in which two, natural size r/c frames were put on shaking table and subjected to a sequence of seismic excitations with increasing intensity interlaced with low level, diagnostic tests. The shaking table experiment aimed at working out new methodology for monitoring vibrations of r/c structures to assess their state. Characteristic decrease of natural frequencies and increase of structural damping was observed and analyzed in detail. It was interesting to note 20 per cent drop in natural frequencies prior to visual detection of any cracks.
Design of innovative friction damper devices for earthquake-resilient RC frames with Hybrid Steel-Trussed Concrete Beams
2021
This thesis focuses on the design of innovative friction damper devices for earthquake-resilient Reinforced Concrete (RC) frames realized with Hybrid Steel-Trussed Concrete Beams (HSTCBs). These devices fall within the framework of the recently-proposed low-damage design strategy for structures built in earthquake-prone areas, on the basis of which the structures are designed to experience negligible damage when subjected to seismic events. The comprehensive solution proposed aims at introducing a feasible option for building earthquake-resilient RC Moment Resisting Frames (MRFs), having been proposed very few solutions for this structural scheme so far. Innovative solutions are proposed fo…
A new large scale laboratory: The LEDA research centre (Laboratory of Earthquake engineering and Dynamic Analysis)
2017
Recently, the field of earthquake engineering experienced substantial enhancements due to numerous results of experimental and theoretical researches. Modern technical codes recognized the last advances in this field and provided new solutions for the structural assessment and design of buildings. However, the need for large scale testing is still taking several open questions, especially for the design of civil infrastructures, and experimental activity on full scale specimens has become necessary. This paper presents the main testing facilities of a new research centre, namely the Laboratory of Earthquake engineering and Dynamic Analysis (LEDA) of the University of Enna “Kore”. In particu…
Evaluating the performance of a new picking algorithm based on the variance piecewise constant models
2021
In this paper, a new picking algorithm for the automatic seismogram onset time determination is tested on a dataset of simulated waveforms. We aim at capturing the variations in the performance due to some characteristics of both the seismic event and its detection, which in turn affect some characteristics of the waveforms. We therefore simulate seismic events with different magnitude, and assumed to be detected with different distances from the nearest seismic station. Our tests permit to highlight the scenarios most suitable for our algorithm.
Spatio-temporal log-Gaussian Cox processes on earthquake events
2016
This work presents an application of spatio-temporal log-Gaussian Cox processes for the description of earthquake events. To explain the overall spatial trend, spatial geological information in the study area such as faults and volcanoes are introduced in the model. Moreover, an anisotropic specification of the covariance matrix of the Gaussian process is used to improve the explanation of the phenomenon. We apply and compare different models to explain the seismic events occurred in Alaska over the last decades.
The influence of building interactions on seismic and elastic body waves
2019
We outline some recent research advances on the control of elastic waves in thin and thick plates, that have occurred since the large scale experiment [S. Brûlé, Phys. Rev. Lett. 112, 133901 (2014)] that demonstrated significant interaction of surface seismic waves with holes structuring sedimentary soils at the meter scale. We further investigate the seismic wave trajectories of compressional body waves in soils structured with buildings. A significant substitution of soils by inclusions, acting as foundations, raises the question of the effective dynamic properties of these structured soils. Buildings, in the case of perfect elastic conditions for both soil and buildings, are shown to int…
Seismic behavior of exterior RC beam-column joints without code-specified ties in the joint core
2021
Abstract Beam-column joint design for reinforced concrete (RC) buildings is a critical issue for modern earthquake engineering, because for these structural elements, the current codes provide several geometrical constraints and reinforcement provisions, which may be very complex to implement during the construction phase. To investigate how a construction error might influence the joint behavior, two identical full-scale exterior beam-column joints specimens are built, according to Italian Building Code specifications for the high ductility class, but without the required horizontal ties inside the joint panel. This construction error could be plausible because, according to the design dra…