Comportamento mecânico de um solo residual naturalmente cimentado

• Autor(a) principal: Oliveira, Ciro Portela de
• Data de Publicação: 2011
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/826
• topic: Cimentação; Solos residuais; Modelo constitutivo; Cementations; Residual Soil; Constitutive model; CNPQ::ENGENHARIAS::ENGENHARIA CIVIL::GEOTECNICA

This thesis presents an experimental and theoretical study of a structured young residual soil of gneiss collected in the city of Rio de Janeiro, Brazil. Triaxial tests were performed following different compression and extension stress paths, such as: axial loading and unloading, lateral loading and unloading, as well as, oedometer tests with the soil in natural and remoulded states. Triaxial tests results showed typical characteristics of a structured soil: gradual change in the mechanical behavior from brittle to ductile with increasing effective confining stress, as well as, smaller stiffness for higher effective confining stress. Results of the oedometer tests also showed that the natural soil is structured, as the model proposed by LEROUEIL & VAUGHAN (1990), in which cementations allows the soil, during confined compression, to achieve stress states beyond those observed in the compression curve of the soil under reconstituted conditions, without cementations between particles. Constitutive model developed for sedimentary soils do not consider the influence of cementation on the mechanical behavior. Therefore, in the theoretical part of this thesis, the Structured Cam Clay mathematical model proposed by LIU & CARTER (2002) was used to fit the experimental results. This constitutive model adds to the Modified Cam Clay model four new parameters to consider the cementation effect in the mechanical behavior of structured soils. Comparisons between the experimental and model results were satisfactory.