Search results for "seismic"

Study of Southern Tyrrhenian and Sicilian regions by a sequential procedure to integrate WAM seismic tomographies and Bouguer anomaly data

2009

A procedure to obtain 3D velocity-density models and earthquake relocation by integrated inversion of P and S wave traveltimes and Bouguer anomaly distribution was applied to a large dataset concerning the Southern Tyrrhenian and Sicilian areas. The seismic dataset was subdivided into two subsets for separate inversions, whose results were later on joined by the WAM (Weighted Average Model) technique. This is a post-processing technique proposed by Calò et al. (2009) by which preliminary tomographic models are unified in a common 3D grid. The first dataset concerns 28873 P and 9990 S arrival times of 1800 earthquakes located in the area 14°30′ E - 17°E, 37°N - 41°N while the second dataset …

Sequential techique for joint inversion of gravimetric and seismic data applied to the Sicilian area

2009

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…

Submarine canyons of north-western Sicily (Southern Tyrrhenian Sea): Variability in morphology, sedimentary processes and evolution on a tectonically…

2014

Special issue Submarine Canyons: Complex Deep-Sea Environments Unravelled by Multidisciplinary Research.-- 13 pages, 11 figures, 2 tables

A low power and high resolution data logger for submarine seismic monitoring

2010

The design, implementation and characterization of a digital waveform recorder for ocean bottom seismic monitoring is here reported. The system is capable of synchronously acquiring, and logging on a flash memory bank, four high resolution signals. Thanks to a very careful design of the system architecture and by using robust digital signal processing techniques, two main conflicting issues have been addressed: a high dynamic range, better than 120 dB, usually obtained with high energy demanding converters, and a power consumption as low as 250 mW, hence allowing to easily increase the time of a continuous submarine monitoring session up to 3 months.

Krill herd algorithm-based neural network in structural seismic reliability evaluation

2018

ABSTRACTIn this research work, the relative displacement of the stories has been determined by means of a feedforward Artificial Neural Network (ANN) model, which employs one of the novel methods for the optimization of the artificial neural network weights, namely the krill herd algorithm. For the purpose of this work, the area, elasticity, and load parameters were the input parameters and the relative displacement of the stories was the output parameter. To assess the precision of the feedforward (FF) model optimized using the Krill Herd Optimization (FF-KH) algorithm, comparison of results has been performed relative to the results obtained by the linear regression model, the Genetic Alg…

Fractal dimension confidence interval estimation of epicentral distributions

1999

Estimates of the fractal dimension of hypocentral distributions require evaluating the range of independent variables in which fractal parameters exhibit a power law. Systematic and accidental errors are produced mainly by the subjective selection of this range, the insufficiency of data sets as well as by hypocenter mislocations. Therefore it is very important to determine the confidence intervals which are associated with fractal dimension estimates. The effects of various sources of errors are studied using different geometric clusters of epicenters, which have been synthetically generated using a multicluster algorithm with different hierarchical levels, so as to reproduce some characte…

Prediction of the out-of-plane response of infilled frames under seismic loads by a new fiber-section macro-model

2016

This chapter suggests that an extension of the capability of the traditional inplane macro-models to capture the simultaneous in-plane and Out-Of-Plane (OOP) response of infills. A new simplified macro-model for the assessment of both in plane and out-of-plane responses of infilled frames was developed and validated. The possibility to simulate the arching action is achieved by using distributed plasticity fiber-section elements, able to directly account for the coupling between axial load and bending moment. The arching action is explicitly introduced by the use of fiber-section beam-column elements, which can model the coupling between axial-load and bending moment. The model presented is…

Gravity modelling of the lower crust in Sardinia (Italy)

1997

In this paper an example is given of an application of statistical techniques to the Bouguer anomalies analysis in order to design a simple crustal model using few a priori assumptions. All gravity measurements carried out in Sardinia have been collected and processed. The Bouguer anomalies have been calculated according to local density estimates. Spectral analysis of the Bouguer anomalies has been carried out along selected profiles in order to estimate the mean depth of the Moho discontinuity and that of an infracrustal discontinuity. The use of this technique inferred the presence of a discontinuity at a mean depth of ~ 28 km, interpreted as Moho and the likely presence of an infracrust…

Solutions for the Design and Increasing of Efficiency of Viscous Dampers

2016

In last decades many strategies for seismic vulnerability mitigation of structures have been studied and experimented; in particular energy dissipation by external devices assumes a great importance for the relative simplicity and efficacy. Among all possible approaches the use of fluid viscous dampers are very interesting, because of their velocity-dependent behaviour and relatively low costs. Application on buildings requires a specific study under seismic excitation and a particular attention on structural details. Nevertheless seismic codes give only general information and in most case the design of a such protection systems results difficult; this problem is relevant also in Italy whe…