Search results for " seismic"

First Evidence of Contourite Drifts in the North-Western Sicilian Active Continental Margin (Southern Tyrrhenian Sea)

2021

We present the results of an integrated geomorphological and seismo-stratigraphic study based on high resolution marine data acquired in the north-western Sicilian continental margin. We document for the first time five contourite drifts (marked as EM1a, EM2b, EM2, EM3a, and EM3b), located in the continental slope at depths between ca. 400 and 1500 m. EM1a,b have been interpreted as elongated mounded drifts. EM1a,b are ca. 3 km long, 1.3 km wide, and have a maximum thickness of 36 m in their center that thins northwards, while EM1b is smaller with a thickness up to 24 m. They are internally characterized by mounded seismic packages dominated by continuous and parallel reflectors. EM2 is loc…

SEISMIC NOISE ANALYSIS OF BROADBAND STATIONS OF THE ITALIAN SEISMIC NETWORK, USING POWER SPECTRAL DENSITY

2022

Seismotectonics in the North-Western Sicily Continental Margin: implications for Geohazard assessment

2017

Active processes in the Northern Sicily Continental Margin (NSCM) have been analysed to produce a seismotectonic map, in order to obtain a useful tool for the assessment of the seismic hazard of the sea-land region. The seismotectonic map is composed of overlapping layers that represent the distribution of different features, such as lithostratigraphy, tectonic elements, seismicity, heat flow, gravimetry, magnetometry, Moho depth, horizontal and vertical movements, submarine landslides, fluid emissions, outlining the mutual relationship and the active structures. The NSCM is suitable to test this approach because it’s located in a transitional area between the Sicilian-Maghrebian chain to t…

SEISMOTECTONIC MAP OF THE NORTHERN SICILY CONTINENTAL MARGIN (NSCM) AND IMPLICATIONS FOR GEOHAZARD ASSESSMENT

2018

The Sicily dominates the central Mediterranean Sea. The Northern Sicily Continental Margin (NSCM) is a segment of the Appeninic-Tyrrhenian System whose upbuilding refers to both the postcollisional convergence between Africa and a very complex “European” crust (Bonardi et al., 2001) or AlKaPeKa (sensu Boullin, 1986) and the opening of the Tyrrhenian back-arc basin. Seismostratigraphic and structural analysis of a large number of available (from ViDePi project) and unpublished (from Department of Earth and Marine Science of the University of Palermo) multichannel seismic reflection profiles acquired across the NSCM, allow us to produce an accurate seismotectonic map, in order to obtain a use…

The SI.RI.PRO. Project: field stratigraphical-structural data from the N-S central Sicily transect

2010

Progetto di Strutture in acciaio per le nuove costruzioni e per gli interventi di consolidamento. IV Edizione

2005

The book is a state of the art summary of recent development in the behavior, analysis and design of steel and composite structures. The book provides advanced students, researchers al professionals in civil and structural engineering with the basic principles upon which the modern codes are based. In the first part, the materials, the actions and the sectional behavior are analyzed on the base of the limit state theory. Then the connections (bolted and welded)and the stability effects are examined. In this way is possible speak about seismic performance, retrofitting an refurbishment of existing buildings, referring to the italian rules, to the european codes EC3, EC4 and to the AISC rules.

On the structural optimization in presence of base isolating devices

2012

The minimum volume design of plane frames constituted by elastic perfectly plastic material and subjected to appropriate combinations of fixed, cyclic and dynamic loads is studied. The influence on the design, in terms of cost (volume) and behavioural features, of seismic protecting devices is particularly focused. The considered protecting device is a lead rubber bearing base isolation system. Two optimal design problem formulations are proposed for the structure with or without the protecting device, both based on the so-called statical approach. The minimum volume frame is reached accounting for three different resistance limits: the purely elastic limit, the (elastic) shakedown limit an…

Timber framed with masonry infill: a historical anti-seismic device. The Portuguese Pombaline gaiola.

2017

La ricostruzione postsismica e la prevenzione sismica sono stati da sempre un fondamento costruttivo.Questo studio analizza la tipologia costruttiva della gaiola pombalina, un sitema costruttivo e strutturale molto diffuso in Portogallo ma non solo, adottato a Lisbona a seguito del terremoto del 1755. Si analizzano i materiali e le tecniche costruttive, gli elementi utili al rinforzo e consolidamento della struttura muraria, ampiamente diffuso in area mediterranea a partire dal XVIII secolo.Questo sistema costruttivo può e deve anche oggi essere considerato un utile presidio antisismico da riconoscere e preservare da interventi incolti, se non addirittura da incongrue demolizioni. Post-seis…

Passive Control of Linear Structures Equipped with non-Linear Viscous Dampers and Amplification Mechanism

2008

Fluid damper devices in civil structures such as buildings or bridges are commonly used as energy absorbers for seismic protection. The problem in the response analysis of structures with filled dampers mainly consists in the fact that, due to the strongly nonlinear behavior of such equipments, the response spectrum technique fails. Moreover, in order to enhance the damping effect various toggle brace configurations have been recently proposed. In this paper by using the concept of power spectral density function compatible with the elastic response spectrum and the stochastic linearization technique, the equivalent damping ratio is obtained. It is shown that once the system is linearized r…

Evolution of Seismicity During a Stalled Episode of Reawakening at Cayambe Volcano, Ecuador

2021

Cayambe Volcano is an ice-capped, 5,790 m high, andesitic-dacitic volcanic complex, located on the equator in the Eastern Cordillera of the Ecuadorian Andes. An eruption at Cayambe would pose considerable hazards to surrounding communities and a nationally significant agricultural industry. Although the only historically documented eruption was in 1785, it remains persistently restless and long-period (LP) seismicity has been consistently observed at the volcano for over 10 years. However, the sparse monitoring network, and complex interactions between the magmatic, hydrothermal, glacial, and tectonic systems, make unrest at Cayambe challenging to interpret. In June 2016 a seismic “crisis” …