1,720,956 research outputs found
Influence of pile tip geometry on soil displacements around jacked piles in layered ground
No full textComportamento di una platea di pali infissi staticamente durante la sua costruzione e nelle prime fasi di esercizio
No full textBehaviour of a piled raft foundation during its construction and first operating conditions The expansion of Customs and Excise Station in Fiumicino (Rome, Italy) involved the construction of some buildings in proximity to Tevere river delta and Leonardo da Vinci international airport. With reference to figure 1, the project included the design and the construction of: two main buildings (A and B, whose dimensions in plan are about 14 m x 58 m and 18.5 m x 48 m, respectively); a technological building (E); two smaller structures (not in the figure). The poor mechanical properties of the subsoil (about 70 m of a thick deposit of normally consolidated alluvial clay resting on a gravel layer; Figs. 2 and 3) suggested for the main buildings the use of piles of displacement type. In particular, jacked steel tubular Soles piles were driven up to the gravel. The choice of a proper pile type was attentively considered in order to fulfil two conflicting requirements: to install very long piles (70 m and more) with a very limited in height equipment (15 m) in order not to interfere with air space of the nearby landing strip n. 3 of the airport. Both the requirements were accommodated by adopted pile, installed by a 3 m height equipment. In the paper, after a short description of subsoil profile and soil properties, some information are given about the project of the piled foundations. Moreover, a description of the monitoring system is also given (Fig. 5); it consists of: high precision topographic survey of 18 benchmarks installed on the rafts (9 for each raft, Figs. 8a and 12b); pore pressure measurements by an electrical piezometer transducer (Figs. 8b and 12d); several vibrating wire transducers placed along 2 pile shafts and at the head of other 5 piles. Due to the specific pile installation procedures, monitoring started during the installation of the piles in order to measure displacements of the raft and pore pressure increase. Details about pile behaviour have been obtained by performing 2 load tests on production piles (1.5 times the expected maximum design axial load); one of them (pile 1A; Figs. 10 and 11) has been instrumented along the depth in order to get information about the load transfer along the shaft and at the base. The whole set of information obtained from the monitoring system provided useful indications about the qualitative behaviour of the foundation system. With particular reference to the complex raft-piles-soil interaction, it has been highlighted the major role played by the specific installation procedure of Soles piles: the excess of pore pressure generated during their installation and the continuously variable constraint conditions due to the progressive structural pile-raft connection have determined very different residual loads for the piles, therefore influencing the final distribution of the load among the piles as a function of their installation time, position and connection. If compared with classical analyses of piled rafts, for which the load sharing between raft and piles, as well as load distribution, is mainly governed by soil, raft and pile properties, it is clear that the case under examination is much more complex because of the influence of the specific installation procedure adopted case by case. Further theoretical and experimental investigations are therefore needed and will be carried out in a next future
Effects of residual stresses on shaft friction of bored cast in situ piles in sand
No full textThe existence of residual stresses locked-in prefabricated displacement piles is a well-known problem and has been
addressed by a number of researchers in the last decades. This is not the case with cast in situ piles: as a consequence of concrete
curing, pile-soil interaction starts soon after concrete casting, causing stress changes in terms of both normal and shear stresses.
Such circumstance has been confirmed by few experimental evidences, reported in the paper, in saturated or dry soil conditions.
In order to evaluate the influence of residual stresses on the subsequent pile response to axial loading, a broad parametric
study has been carried out by means of numerical modelling. Particular focus is given to the effects induced on the shaft friction
of floating bored piles embedded in wet and dry sandy soils.
The results have been interpreted with the aim of highlighting errors commonly made if a stress-free pile is assumed when
interpreting a specific load test results on instrumented piles and/or arranging general design methods
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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