Thesis (M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (ℓ. 128-132)

[pt] Os pavimentos nada mais são que um sistema de múltiplas camadas, solicitados por um pneumático. Nas últimas três décadas inúmeras pesquisas tem sido direcionadas para o estudo de pavimentos. Porém, estas são complicadas, pois os pavimentos são estruturas físicas com interações de um grande número de fatores complexos e interdependentes. Dentre esses,podemos citar os parâmetros geotécnicos dos materiais, as características geométricas das camadas, a forma e intensidade do carregamento e fatores naturais. Este estudo consiste na análise paramétrica de um sistema de múltiplas camadas,representado por um pavimento constituído de base, sub-base e subleito. São apresentados gráficos normalizados de tensões e deslocamentos, resultados de uma análise por elementos finitos, utilizando, para isso, o programa LUSAS. Com base nos resultados, são analisados aspectos com relação ao desempenho do sistema, tais como: geração de poro-pressão, zona de tração, solicitações drenadas e não- drenadas,variação da geometria do conjunto e variação das propriedades geotécnicas dos materiais. Este estudo também compara os resultados encontrados com outras proposições. É verificada uma forte dependência do comportamento de pavimentos com relação às suas características geométricas e propriedades geotécnicas. / [en] This work presents an experimental study of the behavior of rockfills, focusing on the changes caused by rock alteration on the physical and mechanical characteristics, such as, lithology, gradation, deformability and strength. The basalt rockfill used in the construction of Marimbondo dam has been considered, with about 25 years of in situ alteration, together with intact basalts samples from Rio Grande quarry, which is located about 500m downstream from the dam site. The experimental results were also compared with data from tests on granite rockfill samples from Serra da Mesa dam. A methodology is proposed for evaluating the alterability of rockfills, based on laboratory tests on intact and alterated samples. Procedures for fast rock alteration in the laboratory were also developed, attempting to simulate the naturally slow alteration which occurs in the field. The laboratory alteration made use of both continuous leaching and wetting-drying cycles on intact basalt samples. The leaching was imposed in a large scale soxhlet equipment developed in the geotechnical laboratory at PUC-Rio. For the characterization of the geomechanical behavior of the rockfill masses, large scale equipments have been used, such as an confined compression chamber, triaxial compression machine and direct shear box. The results indicate that the intrinsic characteristics play an important role on the rockfill behavior. Furthermore, basalt alteration occurring in the field or in the laboratory may cause a significant decrease on the rockfills stiffness and strength parameters, as well as na increase on the abrasion characteristics of rockfills particles. This study also indicates that leaching in large scale equipment is a proper way to simulate the basalts natural alteration in accelerated laboratory conditions, making possible the long time prevision of the behavior of rockfills. Considering a time period of 75 years of natural alteration in the field, this work presents a quantitative prediction of Marimbondos rockfill behavior in terms of particle breakage, abrasion resistance, compressibility modulus M, deformability modulus E, unconfined strength qu and strength envelope parameters.

Thesis (M.S.) in Civil Engineering--University of Maine, 2001. / Includes vita. Includes bibliographical references (leaves 120-123).

Thesis(M.S.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references.

Thesis (M.S. in civil engineering)--Washington State University, August 2008. / Includes bibliographical references (p. 106-109).

Thesis (M.S.)--University of Nevada, Reno, 2008. / "December, 2008." Includes bibliographical references (leaves 154-156). Online version available on the World Wide Web.

Thesis(M.S.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references (p.116-119).

Thesis(M.S.)--Auburn University, 2005. / Abstract. Vita. Includes bibliographic references (p.61-62).

Thesis--Auburn University, 2009. / Abstract. Vita. Includes bibliographical references (p. 148-153).

Thesis (Ph. D.)--Worcester Polytechnic Institute. / Keywords: Ndesign; Mix Design; Film Thickness; Low Volume Roads; VMA; Hot Mix Asphalt. Includes bibliographical references (p. 63-65).