Determinação e aplicação dos parâmetros de resistência ao cisalhamento de um solo argiloso do município de Goiânia a partir do ensaio triaxial

Abstract

The determination of the parameters of shear strength of a soil is of Paramount importance in civil engineering, especially in relation to the construction of embankments, dams, stability analysis of slopes and others. The objective of this work was to perform the Triaxial test with a clayey soil from the Goiânia metropolitan region of Goiás and obtain the parameters of shear strength in drained and non drained conditions in order to study its application to slope stability of a hypothetical earth dam. However, for this to be accomplished, maintenance and repairs were initially performed on the triaxial equipment of the Federal Institute of Education, Science and Technology of Goiás - IFG Campus Goiânia, putting it back into operation. Some components were replaced and, after two test trials, it was verified that the equipment was fit to perform the tests proposed in the present work. The clay soil sample was selected in order to represent a typical soil of the Goiânia metropolitan region and, prior to the realization of the triaxial tests, its complete characterization was made, that is, the granulometry tests by sieving and sedimentation, mass grain size and consistency limits. Subsequent to the characterization, its geotechnical classification was made in the SUCS and TRB systems and the compaction tests, using the normal Proctor energy and California support index, with immersion of the specimens for 48 hours. The molding conditions were defined by adopting a degree of compaction equal to 95%, in the optimum moisture of the compaction test. For determination of the shear strength parameters, two triaxial test batteries, CU and CD, with confining tensions of 100, 200 and 400 kPa were performed. After obtaining the parameters of soil shear strength, ie cohesion and friction angle, for drained and non drained conditions, the application of said soil in the construction of a mixed earth and rock dam was evaluated using the Seep / W software and Slope / W, student version, from GeoStudio or GeoSlop. Flow and stability analysis was performed only for the dam operation phase, using drainage test data. The results obtained demonstrated the importance of knowing the parameters of shear strength of the soils, the peculiarities of performing triaxial tests in drained and non drained conditions, the applications in geotechnical works and the evaluation of the performance of the hypothetical dam studied.