1,721,076 research outputs found
Use of piezocone to predict maximum stiffness for Venetian soils
No full textA comprehensive geotechnical in-situ and laboratory investigation into the soils forming the upper quaternary basin of the Venetian Lagoon has been recently carried out. The research presented here is particularly concerned with the estimate of maximum tangential stiffness Gmax of the Venetian soils via selected tests such as in situ cross-hole, down-hole and laboratory bender element and resonant column tests. An attempt to relate the maximum stiffness with the results of piezocone test is subsequently performed. Despite their incompatible strain levels, it is shown that an association between Gmax and the two measured quantities - tip resistance qc and generated excess pore pressure du - is quite possible in the case of Venetian soils. Therefore, a relationship linking Gmax to qc and du is proposed, that could find a moderate applicability for a preliminary estimate of Gmax profile with depth in the Venetian ground
Use of an up-scaled DEM model for analysing the behaviour of a shallow foundation on a model slope
No full textCalibration of rheological properties of materials involved in flow-like landslides
No full textOne of the effects of climate change is an expansion of the areas affected by flow-like landslides and an increase in human loss and economic damage caused by these natural hazards. The risk assessment connected to flow-like landslides utilizes several study approaches, such as the mapping of lands affected in the past, the understanding of triggering and propagation mechanisms through the monitoring of some watershed basins periodically subject to flow-like landslides, and the prediction of flow-like landslide propagation by means of advanced mathematical models. Research has made much progress in the development of advanced mathematical models able to account for various rheological models, 3D morphology of the slope, and engagement of other materials from the boundary, etc. Calibration of the parameters is, however, one of the most problematic phases of numerical modelling; the validation of propagation models is usually carried out on the basis of laboratory flume tests executed in very simple conditions or on the basis of data achieved from field observation, which are very often of low quality. After a brief state-of-art review concerning the most recent developments in flow-like landslide modelling, the present paper examines the techniques adopted for calibrating the models. Particularly, it considers the difficulties linked to the upscaling of rheological properties moving from the physical tests performed in viscometer or artificial flume, and attaining the estimation of average properties of the heterogeneous materials involved in real flow-like landslides
Small strain stiffness of Venetian soils from in-situ and laboratory tests
No full textThis paper presents selected results of an extensive in-situ and laboratory geotechnical investigation on Venetian quaternary deposits, which formed part of a project on protection from flooding of the old city of Venice. In particular, the evaluation of the very small strain shear stiffness of cohesive and granular forma-tions by very accurate in-situ and laboratory testing is considered and discussed
Mathematical modelling of Venetian sediment behaviour using Generalized Plasticity
No full textThe paper is concerned with the modelling of the heterogeneous and highly stratified Venetian
sediment behaviour within a theoretical framework known as Generalized Plasticity. Starting from an existing
formulation developed for sands, modifications are introduced into the constitutive equations in order to overcome
some limitations of the original model and to develop a simple and reliable procedure for calibrating the
constitutive parameters, with particular reference to Venetian soils, which range from silty sands to silty clays.
The key point in the new formulation is the use of a material state parameter, whose main goal is to allow unified
modelling of soil behaviour over a wide range of stress levels and void ratios. The approach is validated by
comparing the new model predictions with experimental results of drained compression tests on natural and
reconstituted Venetian soil samples, having different grain size distibutions, under various initial state and
confining pressure conditions
MODELLAZIONE MICROMECCANICA DELL’EFFETTO DELL’EVAPORAZIONE SULLA STABILITÀ DI UN PENDIO GRANULARE
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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