No description available.

Th. Univ.--Electrochimie--Paris 6, 1989. / Résumé en anglais. Bibliogr. p. 193-203.

In this study, the effect of normal stress acting on a model scale pile is determined experimentally. The minimum soil temperature was -5 degrees Celcius. Additional experiments were conducted to determine the adfreeze bond strength of an interface between the Cornwall sand and a galvanized steel plate. These tests were done using a conventional direct shear apparatus. In order to conduct interface tests under freezing temperatures, some modifications were made on the direct shear apparatus. In these experiments, three different normal stresses and three different water contents were used. The present study was extended to investigate whether there was any agreement between the adfreeze strength measured in the present study and the adfreeze strength calculated from the pull-out tests by Villeneuve (2017).

No description available.

La gestion des déchets industriels est devenue une préoccupation majeure ces dernières années. La réglementation de plus en plus stricte et la hausse du prix des métaux incitent les industriels à réduire la quantité de déchets qu'ils produisent, limiter leur caractère polluant et assurer leur valorisation optimale. L'objectif des travaux de recherche entrepris est de procéder à la valorisation de déchets solides zincifères par couplage des deux étapes les plus courantes de l'hydrométallurgie, la lixiviation et l'électrodéposition du métal, au sein d'une seule et même cellule électrochimique. Ainsi la technique utilisés est basée sur la lixiviation du solide par les protons générés électrochimiquement à l'anode et la migration des ions résultants vers la cathode où ils se réduisent pour produire du zinc métallique. Les compositions d'électrolytes et la densité de courant optimale ont été définies lors des études séparées de l'électrolixiviation et de l'électrodéposition. Les expériences ont été réalisées sur un déchet synthétique composé d'oxyde de zinc dispersé dans du sable et à partir d'une cellule à trois compartiments (deux compartiments contenant les électrodes et un placé entre les deux et contenant le solide). Après avoir réalisé le couplage des deux étapes sur le déchet synthétique, ce protocole a été appliqué au traitement de déchets réels, tels que les oxydes pyrométallurgiques provenant du traitement des poussières d'aciérie électrique et les broyats de piles alcalines et salines, dans une cellule à deux compartiments. Ainsi, en imposant une densité de courant de 4,5 A/dm2, la quasi-totalité (99%) du zinc contenu dans le premier solide est lixivié en 6 heures et environ 95% dans le cas des broyats de piles. Dans tous les cas, un dépôt de zinc de haute pureté, utilisable en l'état, est obtenu / Nowadays removal of heavy metals in industrial solid wastes is more and more important because of their high cost and the reduction in available natural resources. This work deals with zinc beneficiation of industrial solid wastes by an electrochemical technique combining electroleaching and electrowinning in a single-cell process. This technique is based on leaching of the solid by the protons generated at the anode and migration of the resulting ions towards the cathode where deposition takes place. Electrolyte compositions and optimal current density were yielded by separate investigations of electroleaching and electrodeposition. Batch experiments were then carried out in a three-compartment cell, two electrode compartments and a solid waste chamber placed between these. The preliminary investigations were conducted using a synthetic waste prepared by dispersing zinc oxide in silicon dioxide (sand). Best performance was obtained in 6 hour treatment, at 4,5 A/dm2, with sulphuric/sulphate solution as anolyte and catholyte and with catholyte circulation. In this case, 97% of zinc oxide leaching and 75% of zinc-could be recovered in the form of deposited metal. Then this technique has been developed for the batch treatment of real metal oxides issued from pyromettallurgical oxide and around 95% forspent batteries. A high purity zinc deposit was produced

The use of auger cast-in-place (ACIP) pilings is very common in Florida; however, there is a significant degree of uncertainty in determining the actual capacity of the pilings, especially when the pilings are installed through layers of cohesive soils. Therefore, there is a need to improve upon the existing methods of predicting the behavior of ACIP piles in layered soils. As a result, the primary objective of this study is to determine if a significant difference exists between the accepted methods of pile load test analysis. Provided a significant difference is noted, the secondary objective would be to determine if an improvement could be made to enhance the existing empirical relationships used to predict pile behavior in layered soils. In order to accomplish these objectives, this study presents an evaluation of some of the most commonly used methods for predicting ACIP pile capacity based upon the results of actual field load tests. Data from twenty-five load tests were analyzed using popular methods and statistical analyses were preformed to determine and evaluate the data. These evaluations were utilized to explore correlations between predicted behavior and actual results. Based upon the results of this study, there is no statistically significant difference between the load test analyses methods examined. As a result, no improvement to the existing methods of predicting ACIP pile behavior in layered soils may be recommended at this time, and further research in this subject matter is recommended.

No description available.

O presente trabalho apresenta uma análise do desempenho de estacas hélice contínua e ômega, com ênfase na influência do processo de execução e aspectos executivos. É feita uma revisão bibliográfica apresentando a evolução executiva das estacas, o processo executivo e aspectos relevantes à correta execução destas estacas, características dos materiais que influenciarão o desempenho, efeitos da execução das estacas no sistema estaca-solo e uma análise da influência da geometria da ponta no desempenho das estacas. Três casos de obras são mostrados. Primeiramente uma obra que, devido a alterações das propriedades do concreto, substituiu-se estacas hélice contínua por ômega, como solução ao problema apresentado. Em seguida, mostra-se a execução de estacas ômega na Estação Vila das Belezas. Por último, o interessante caso de utilização de estacas hélice contínua como elemento de contenção nas obras do projeto integração centro, na Estação Luz, onde a proximidade de prédios antigos era fator limitante na escolha do tipo de fundação. Apresenta-se, ainda, uma análise comparativa do desempenho de estacas hélice contínua e ômega por meio de resultados de provas de carga, e uma análise do desempenho inesperado, da ponta, de uma estaca ômega, por meio de interpretação de prova de carga na estaca e do parâmetro R de Cambefort. São apresentados, também, os métodos de previsão de capacidade de carga de estacas hélice contínua e ômega, de extrapolação da curva carga x recalque e de separação das cargas de atrito e ponta, que foram utilizados nas análises de desempenho das estacas. / This research work presents an analysis of the performance of CFA and omega piles, with emphasis on the influence of execution processes. A review of previous work is presented, showing the construction evolution of these piles, it’s execution process and relevant aspects concerning the correct execution of these piles, as well as material properties effecting on it’s behavior, execution effects on the pile-soil system and an analyses of the influence of the pile’s tip on it’s performance. Three cases of foundation works are shown. First of all, a piled foundation in which CFA piles were changed to omega piles, due to alterations in the concrete properties. After that, an omega pile execution on Vila das Belezas subway station is shown. At last, an interesting case of CFA piles as a retaining wall, on Luz subway station, where proximity old buildings restrained the choice of retaining methods. A comparative analysis of the performance of omega and CFA piles, based on load tests, is also shown, as well as an analysis of the unexpected behavior of an omega pile tip, based on an interpretation of load test and Cambefort’s R parameter. In addition to this, the predict methods of bearing capacity, the methods of extrapolation of the load-settlement curve and the methods of the separation of the shaft friction and the end bearing, which were used in the performance analysis of the piles, are also presented.

O presente trabalho apresenta uma análise do desempenho de estacas hélice contínua e ômega, com ênfase na influência do processo de execução e aspectos executivos. É feita uma revisão bibliográfica apresentando a evolução executiva das estacas, o processo executivo e aspectos relevantes à correta execução destas estacas, características dos materiais que influenciarão o desempenho, efeitos da execução das estacas no sistema estaca-solo e uma análise da influência da geometria da ponta no desempenho das estacas. Três casos de obras são mostrados. Primeiramente uma obra que, devido a alterações das propriedades do concreto, substituiu-se estacas hélice contínua por ômega, como solução ao problema apresentado. Em seguida, mostra-se a execução de estacas ômega na Estação Vila das Belezas. Por último, o interessante caso de utilização de estacas hélice contínua como elemento de contenção nas obras do projeto integração centro, na Estação Luz, onde a proximidade de prédios antigos era fator limitante na escolha do tipo de fundação. Apresenta-se, ainda, uma análise comparativa do desempenho de estacas hélice contínua e ômega por meio de resultados de provas de carga, e uma análise do desempenho inesperado, da ponta, de uma estaca ômega, por meio de interpretação de prova de carga na estaca e do parâmetro R de Cambefort. São apresentados, também, os métodos de previsão de capacidade de carga de estacas hélice contínua e ômega, de extrapolação da curva carga x recalque e de separação das cargas de atrito e ponta, que foram utilizados nas análises de desempenho das estacas. / This research work presents an analysis of the performance of CFA and omega piles, with emphasis on the influence of execution processes. A review of previous work is presented, showing the construction evolution of these piles, it’s execution process and relevant aspects concerning the correct execution of these piles, as well as material properties effecting on it’s behavior, execution effects on the pile-soil system and an analyses of the influence of the pile’s tip on it’s performance. Three cases of foundation works are shown. First of all, a piled foundation in which CFA piles were changed to omega piles, due to alterations in the concrete properties. After that, an omega pile execution on Vila das Belezas subway station is shown. At last, an interesting case of CFA piles as a retaining wall, on Luz subway station, where proximity old buildings restrained the choice of retaining methods. A comparative analysis of the performance of omega and CFA piles, based on load tests, is also shown, as well as an analysis of the unexpected behavior of an omega pile tip, based on an interpretation of load test and Cambefort’s R parameter. In addition to this, the predict methods of bearing capacity, the methods of extrapolation of the load-settlement curve and the methods of the separation of the shaft friction and the end bearing, which were used in the performance analysis of the piles, are also presented.

Reproduction de : Thèse de doctorat : Génie électrique : Toulouse, INPT : 2005. / Titre provenant de l'écran-titre. Bibliogr. 101 réf.