1,721,774 research outputs found
A simple expression of the shear strength of anisotropic fibre-reinforced soils
No full textThis paper refers on the shear strength of soils reinforced with short randomly distributed fibres, which is a new and effective ground improvement technique. The shear strength of these soils is usually anisotropic because of compaction. In the paper, some of the main characteristics of these soils, and some considerations on anisotropy in strength are reported. Than, the expression recently introduced by Lirer et al. (2011) to simply model the failure envelope of the reinforced soil is discussed. This expression is based on simple micromechanical considerations and on a number of experimental results, and takes into account the main characteristics of the soil and of the fibres as well as the effect of fibre to grains relative dimensions. However, it only allows to calculate the maximum value of the shear strength of the composite material, being related to the results obtained in triaxial compression tests with fibres mostly oriented in the horizontal direction. In the paper, a possible evolution of the formulation of this shear strength envelope is proposed, to take into account anisotropy. A simple trigonometric reduction function is introduced, which complies with the expected behaviour of reinforced soils under different loading conditions. The proposed approach has the advantage of being a rather general expression that can be used by knowing just some simple and basic information on the host soil and on the fibres
An innovative approach for reducing the seismic risk of existing buildings and historic sites.
No full textThe seismic risk is one of biggest challenges for civil engineers, and a number of mitigation
strategies have been developed in time with reference to existing or new buildings. Nowadays, refined techniques
based either on structural reinforcement or seismic isolation exist to protect new and existing structures
from seismic shaking. This paper presents some results of a research activity in progress at the University of
Napoli Federico II (Italy), aimed to check the effectiveness of an innovative approach for reducing the seismic
risk by using soft grouting mixtures installed at an optimum depth in the foundation soil. The basic idea is that
a thin grouted layer, with a dynamic impedance much smaller than that of the surrounding soil, will filter most
of the seismic ground motion, with very little energy being transmitted to the overlying soil. The effectiveness
of the insertion of a soft grouted layer in the range of frequency affecting the response of squat buildings was
numerically tested via a parametric analyses, with reference to a simplified one-dimensional scheme
Paleoclimatic changes in the Serravallian record of the Mediterranean area
No full textGrzybowsky Foundation Special Publicatio
Lirer, Thomas: Chronik von allen Königen und Kaisern. Ulm 1486
No full textVom GW unbemerkt, hat die Evangelische Landesbibliothek in Budapest ihr Lirer-Exemplar ins Netz gestellt: https://library.hungaricana.hu/en/view/EvangelikusOsnyomtatvanyok_EOK_R_1480_1/?pg=0&layout=s In meinem lückenhaften Census von 1987 Nr. 32. Was mag das für ein Holzschnitt sein? #inkunabe
Volcanic hazard and risk assessment in a multi-source volcanic area: the example of Napoli city (Southern Italy)
Full text linkThe possible emplacement of pyroclastic fall and flow products from Campi Flegrei and Somma-Vesuvio represents a threat for the population living in Napoli city. For this area, the volcanic hazard was always partially investigated to define the hazard related to the Campi Flegrei or to the Somma-Vesuvio activity one at a time. A new volcanic hazard and risk assessment, at the municipality scale, as a vital tool for decision-making about territorial management and future planning, is presented here. <br><br> In order to assess the hazard related to the explosive activity of both sources, we integrated the results of field studies and numerical simulations, to evaluate the future possibility for Napoli to be hit by the products of an explosive eruption. This is defined for the Somma Vesuvio central volcano through the sum of "field frequency" based on the thickness and distribution of past deposits (Lirer et al., 2001), and for the Campi Flegrei volcanic field by suitably processing simulated events based on numerical modelling (Alberico et al., 2002; Costa et al., 2009). Aiming at volcanic risk assessment, the hazard areas were joined with the exposure map, considered for our purposes as the economical value of artefacts exposed to hazard. We defined four risk classes, and argued that the medium and low-very low risk classes have the largest extent in Napoli municipality, whereas only few zones located in the eastern part of the city and in the westernmost coastal area show a high risk, owing to the correspondence of high economical value and high hazard
Integrated Stratigraphy (Cyclostratigraphy and Biochronology) of Middle Miocene deposits in teh Mediterranean Area and comparison with Atlantic Ocean
No full text
ANALISI SPERIMENTALE E NUMERICA DELL'INTERAZIONE FRA UNA COLTRE ED UNA FILA DI PALI
No full textAnna Maria Ferrero, Francesco Silvestri, Claudio Scavi
Dispersione e fallout di ash da una colonna eruttiva sostenuta: applicazione del modello numerico PUFF per la simulazione continua della dispersione di ash in atmosfera.
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