Thesis (M.S.)--Ohio University, November, 1999. / Title from PDF t.p.

Thesis (M.S.)--Missouri University of Science and Technology, 2008. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed October 20, 2008) Includes bibliographical references.

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references. Also available on the Internet.

Thesis--Auburn University, 2009. / Abstract. Vita. Includes bibliographical references (p. 58-59).

Thesis--Auburn University, 2008. / Abstract. Includes bibliographic references.

Thesis (Ph.D.)(Civil Engineering)--University of Pretoria, 2005. / Includes summary. Includes bibliographical references.

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Typescript. Vita. Title from title screen of research.pdf file (viewed on March 6, 2009) Includes bibliographical references.

Resumo: O objetivo do vigente trabalho foi avaliar a qualidade física de um LATOSSOLO VERMELHO Eutroférrico, textura argilosa, cultivado com as variedades de soja (CAC-1 e FT-Cristalina), submetidos aos efeitos da compactação e da irrigação, utilizando os atributos físicos do solo e associá-los ao crescimento radicular e à produtividade da cultura da soja, em experimentos conduzidos em campo e em casa de vegetação (vasos). O experimento de campo constou de parcelas subdivididas, com quatro repetições cujos tratamentos principais foram constituídos por quatro níveis de compactação, proporcionados pelo tráfego controlado de tratores, três níveis de irrigação e duas camadas de solo (Capítulos 2 e 3). Foram coletadas amostras indeformadas do solo nas camadas de 0-0,10 e 0,10-0,20 m, para determinação dos atributos físicos. A produtividade máxima da soja foi obtida com a resistência do solo à penetração de 0,71 e 1,88 MPa para as variedades CAC-1 e FT-Cristalina, respectivamente. Foi obtido o valor de "S" de 0,036 e redução nos níveis mais compactados para 0,026. O experimento de casa de vegetação apresentou parcelas subdivididas com três repetições cujas variedades CAC-1 e FT-Cristalina diminuíram o comprimento de raízes à medida que aumentou a compactação e consequentemente reduziu a área explorada pelas raízes (Capítulo 4) / Abstract: The aim of the current study was to evaluate the physical quality of an Eutrustox, clayey texture, cultivated with soybean varieties (CAC-1 and FT-Cristalina), submitted to the effects of soil compaction and irrigation, using the physical attributes of soil and associates them to root growth and yield of soybean culture, in experiments conducted in field and greenhouse (vases). The field experiment consisted of split plots, with four replications, where the main treatments was consisted of four levels of compaction, induced by controlled tractors traffic, three levels of irrigation and two layers of soil (Chapters 2 and 3). Undisturbed samples of soil were collected in the layers of 0-0,10 and 0,10-0,20 m, to determine the physical attributes. The maximum yield of soybeans was obtained with the soil resistance to penetration of 0,71 and 1,88 MPa for the varieties CAC-1 and FT-Cristalina, respectively. It was obtained the "S " value of 0,036 and a reduction in the levels more compressed to 0,026. The greenhouse experiment showed a split plot design with three replications whose varieties CAC-1 and FT-Cristalina decreased the root length as increased the compaction and consequently reduced the area explored by the roots (Chapter 4) / Orientador: José Frederico Centurion / Coorientador: Maria Aparecida Pessôa da Cruz Centurion / Banca: José Renato Zanini / Banca: Alberto Carvalho Filho / Mestre

M.Tech. / There is a general lack of understanding of the laboratory compaction test based on the vibrating hammer method. The impact method of testing soil in the laboratory is conservatively used by engineers for design and construction control purposes even when the specified mode of compaction on site is vibratory. Furthermore, the effects of vibratory compaction are not fully understood, and hence this mode of compaction in the field has not always been effectively utilized. The objective of this research project was to determine whether the vibrating hammer method could be used in the laboratory for design and control purposes, through an investigation of its operating characteristics, and a comparison of its effectiveness against that of the impact method, following a study of the compaction properties of a range of different soils used in road and embankment construction. The results of the study showed that the vibrating hammer can be used in place of impact in the laboratory for non-cohesive soils and gravels. In one instance, vibratory compaction produced maximum dry densities for a decomposed granite which were almost 5 % higher than that for impact compaction. Cohesive soils reached maximum compaction at moisture contents which were 7 % wetter under the vibratory mode as opposed to those for impact, but at lower densities. This showed that field densities under vibratory compaction would be difficult to achieve when the laboratory control method was based on impact. The research showed that electrical power input to the vibrating hammer must be carefully regulated in order to maintain specified standards which are based on a fixed frequency. Further study based on operation at different frequencies would be required to determine whether the vibrating hammer would be suitable for cohesive soils having natural frequencies lower than the current standard specified.