Influência de variáveis de compactação na estrutura dos solos: caracterizações geotécnica, química, mineralógica e microestrutural

• Ano de defesa: 2010
• Autor(a) principal: Crispim, Flavio Alessandro
• Orientador(a): Lima, Dario Cardoso de
• Banca de defesa: Soares, Ecidinéia Pinto , Alcântara, Marco Antônio de Morais
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Engenharia Civil
• Departamento: Geotecnia
• País: BR
• Palavras-chave em Português: Compactação dos solos; Estrutura dos solos; Caracterizações geotécnica; Química; Mineralótica; Microestrutural
• Palavras-chave em Inglês: Soil compaction; Soil structure; Geotechnical characterizations; Chemical; Mineralogical; Microstructural
• Área do conhecimento CNPq: CNPQ::ENGENHARIAS::ENGENHARIA CIVIL
• Link de acesso: http://locus.ufv.br/handle/123456789/822

This research addressed the effect of laboratory methods of static and dynamic compaction on compaction parameters, mechanical strength and compressibility of three gneiss residual soils (two young and one mature soils) and two granite residual soils (one young and one mature soils) from the Minas Gerais State, Brazil. Disturbed soils samples were collected, and the laboratory testing program encompassed the following aspects: (I) geotechnical, chemical and mineralogical soils characterization; (ii) laboratory methods of static and dynamic compaction performed at the Standard Proctor compaction effort; (iii) compaction tests performed at wot-3%, wot and wot + 2% moisture contents; (iv) mechanical strength tests; (v) anisotropy and compressibility parameters studies (secant and initial tangent elasticity modules); (v) micromorphology studies performed in thin sections from the vertical plane of soils specimens, in order to evaluate the influence of compaction modes in soils structures; (vi) statistical analysis including mean tests and models identity. For practical engineering purposes, conclusions were as follows: (i) with regard to the compaction parameters, at soils optimum moisture content the specific dry weight and unconfined compression strength of structured soils specimens (soils 1, 3 and 4) statically compacted were greater than of dynamically compacted, as well as reversed behavior was observed in the sandy soils (soils 2 and 5); (ii) regarding the effect of anisotropy in the mechanical strength parameters, in the static compaction it was observed influence on the effective friction angle (φ') and on the effective cohesion intercept (c ), and in the dynamic compaction it was noticed influence only on the effective cohesive intercept, independent of soil type; (iii) regarding the compressibility behavior and in terms of optimum compaction parameters, the soils 2, 3 e 4 statically compacted were more deformable (smaller modules) at 0° and 90°, not showing significant important differences at 45º; when dynamically compacted the other soils were more deformable at 0º and 45º; (iv) incorporation of micromorphological and mineralogical analysis was an important tool to analyze soils structure mechanisms. Micromorphological analysis allowed the identification of cracks caused by the dynamic compression mode, as well as pedoforms, aggregations and the degree of destruction of them caused by each compression mode; on the other hand, mineralogical analysis helped the interpretation of the mechanical behavior of soils regarding the tested water content and compaction procedures.