Search results for "SEISMIC"
showing 8 items of 338 documents
Spatial analysis of the Italian seismic network and seismicity
2018
Seismic networks are powerful tools for understanding active tectonic processes in a monitored region. Their numerous applications, from monitoring seismicity to characterizing seismogenic volumes and generated seismicity, make seismic networks essential tools for assessing seismic hazard in active regions. The ability to locate earthquakes hypocenters requires a seismic network with a sufficient number of optimally distributed, stations. It is important to assess existing network geometry, to identify seismogenic volumes that are not adequately monitored, and to quantify measures that will allow network improvement. In this work we have studied the spatial arrangement of the stations of th…
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…
L'utilizzo del ferro a Palermo dopo il terremoto del 1726
2016
La ricerca, basata essenzialmente sullo studio di una consistente mole di documenti emersi attraverso nuove indagini archivistiche, mira a indagare gli aspetti tecnici legati agli interventi sul patrimonio architettonico di Palermo successivi al terremoto del 1726, approfondendo il ruolo degli architetti e dei maestri coinvolti nel processo di ricostruzione delle fabbriche colpite e ponendo particolare attenzione alle tecnologie messe in atto facenti ricorso all’uso ferro, indagate attraverso lo studio di alcuni casi esemplificativi. Questo materiale, infatti, trovò in questa occasione diverse applicazioni. L’intervento più frequente fu relativo all’inserimento di catene in ferro in corrisp…
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” …
HIGH-RESOLUTION SEISMIC SURVEY IN THE WESTERN CALABRIA AND EASTERN SICILY OFFSHORE: IMPLICATIONS WITH VERTICAL TECTONICS
2016
High-resolution seismic data acquired along the continental shelf/upper slope offshore of Capo Vaticano (western Calabria), Milazzo Promontory and Mt. Etna (eastern Sicily) allow to provide new insights on vertical mobility related to active tectonics. A number of depositional sequences bounded by unconformities or correlative para-conformities were recognized on Sparker profiles in the first 200-300 m below the sea-floor. The most recent sequence overlays a widespread erosional surface that ostensibly formed during the sea level stillstand of the Last Glacial Maximum (LGM), whereas a stack of depositional sequences, which are interpreted as representing the falling and low-stand systems tr…