1,720,959 research outputs found
Límites del empirismo en ingeniería de rocas
Full text linkFil: Rocca, R. J. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.La ingeniería de rocas es una disciplina que emplea ampliamente métodos empíricos en el
diseño de excavaciones tanto superficiales como subterráneas. Posiblemente se debe a una evolución
algo más retrasada con relación a otras ramas de la Geotecnia. Una de las causas reside en las
propiedades de los macizos que son dependientes de la escala y por lo tanto, condiciona a los resultados
que se obtienen en el laboratorio.
Se analizan límites como umbrales de comparación que incluyen algunos casos extremos de la
naturaleza, tanto en excavaciones superficiales como subterráneas.
También se tienen en cuenta limitaciones del empirismo cuando se realizan verificaciones analíticas y se
encuadra el empleo del empirismo en el diseño ingenieril. Se describe el origen de algunas relaciones
empíricas y se trata de indagar cuales son las consecuencias del empleo de las mismas. Incluye el uso de
clasificaciones de macizos para determinar refuerzos en túneles y taludes. También el uso de medios
continuos equivalentes y las derivaciones del modelo de Hoek Brown. Se mencionan algunos casos y la
influencia del empleo de empirismo en excavaciones en rocas.Fil: Rocca, R. J. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Otras Ingeniería Civi
Influence of nearby structures in the design of a road tunnel
Full text linkFil: Varde, O.A. Vardé y Asociados. Buenos Aires; Argentina.Fil: Rocca, R. J. Universidad Nacional de Córdoba; Argentina.Fil: Zeballos, M.E. Universidad Nacional de Córdoba; Argentina.Fil: Terzariol, R.E. Universidad Nacional de Córdoba; Argentina.The design and construction of a road tunnel must include variables, parameters and components related to the type and use of the tunnel. If in the vicinity of the project there is another tunnel and infrastructure with high sensitivity, the design has a greater complexity. The road tunnel is located in the stock of Cachueta, Mendoza, Argentina. Along with the complexity of the tunnel location site, two important elements have affected the design: the presence of a lower tunnel, corresponding to an aqueduct that serves for the provision of water to a city of more than one million people, and the presence of a dam of the CFRD type. As a test to evaluate damages in both nearby structures, blasting tests were carried out. The results were also used to measure the effect of the construction on the nearby dam. The main components of the established design are presented.Fil: Varde, O.A. Vardé y Asociados. Buenos Aires; Argentina.Fil: Rocca, R. J. Universidad Nacional de Córdoba; Argentina.Fil: Zeballos, M.E. Universidad Nacional de Córdoba; Argentina.Fil: Terzariol, R.E. Universidad Nacional de Córdoba; Argentina.Ingeniería Civi
Suffusion in compacted loessial silts. Interaction with granular filters
Full text linkFil: Terzariol, R. E. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Rocca, R. J. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Zeballos, M. E. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Loess soils, which occupies much of central Argentina, is characterized by its high sensitivity to change in moisture. This condition categorized loess structure as internally unstable soil. Despite this natural condition, silts derived from loess are frequently used as material in roads and hydraulics constructions. In filtration processes, the soil should be shielded from erosion phenomena. The filter must have a particle size consistent with the ground to protect. In particular, sandy silts can be affected by phenomena of suffusion, or internal instability of the soil structure. The filter must control the loss of material and ensure the stability of flow. The present study shows the experimental results of flow applied to loessial silts, with low compaction. Tests have been conducted using filtration columns that simulate the soil-filter-drain. The test methodology applied aims to follow the research lines of similar studies worldwide. Studies have focused on analyzing the influence of variables such as degree of compaction, hydraulic gradient and composition of the filter material. The results obtained allow recommendations with reference to construction systems to be applied and the composition of the filter in order to properly control the suffusion.Fil: Terzariol, R. E. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Rocca, R. J. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Zeballos, M. E. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Otras Ingeniería Civi
Loess self-collapsibility of Córdoba
Full text linkFil: Rocca, R. J. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Terzariol, R. E. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Zeballos, M. E. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Los suelos loessicos son suelos inestables frente a variaciones de humedad. Su comportamiento no es uniforme y desde hace más de setenta años se conoce que la inestabilidad, denominada colapsibilidad, varía de acuerdo con las características internas de los suelos. Por ello, se han desarrollado métodos en Argentina para su correcta identificación cuando hay variaciones de humedad, separando los potencialmente colapsables, que dependen de cargas externas, de los auto-colapsables que se asientan bajo su propio peso. Estos métodos son comparables con los desarrollados en otras regiones donde el fenómeno es importante, como Estados Unidos, China, Rusia y países adyacentes. La ciudad de Córdoba es uno los sitios donde mejor se ha estudiado el comportamiento metaestable que genera la auto-colapsabilidad. Esto comprende estudios de laboratorio y de campo, con desarrollo de ensayos sobre los suelos y las estructuras de fundación que se apoyan sobre ellos. Se presentan casos registrados de incidentes de auto-colapsibilidad y la información disponible con la cuantificación de la incertidumbre de la distribución areal mapeada, en la ciudad de Córdoba. Esto incluye tanto al norte como al sur de la zona influenciada por el río Suquía. Para la determinación de la distribución areal de las características de la colapsibilidad se han empleado distintos métodos de estimación geoestadística y de simulación.Fil: Rocca, R. J. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Terzariol, R. E. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Zeballos, M. E. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Ingeniería de la Construcció
Inverse analysis of shallow foundation settlements on collapsible loess: Understanding the impact of varied soil mechanical properties during Wetting
No full textLoess soil presents a collapsible behavior and suffers significant settlements due to wetting that can seriously
affect the structures supported on it. The increase in water content produces a permanent change in loess soil
microstructure and sudden volume reductions. In this work, a hydro-mechanical (H-M) model is presented to
analyze the soil response and the behavior of strip foundations on loess soil using a 2D finite element model.
Numerical models were calibrated, on one hand, from experimental data of double oedometer tests and soil
water retention curve; and on the second hand, by retrofit analysis from the measurement of settlements in fullscale
foundation prototypes over collapsible loess during controlled water pipe leakage. The settlements were
studied by performing statistics, sensibility, and inverse analyses. Final settlements after 2 years of infiltration of
water were computed using Monte Carlo simulations. The results show that the compression index at saturation
is the most significant parameter controlling the behavior of collapsible loess. Optimum sets of parameters were
achieved with inverse analysis, demonstrating the accuracy of the H-M model to predict collapse-induced settlements
of shallow foundations
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
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