Banca de DEFESA: Daniela Giroto Amorim

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : Daniela Giroto Amorim
DATE: 10/07/2024
TIME: 08:30
LOCAL: Sala Teams (On-line)
TITLE:

Evaluation of geotechnical behavior of an experimental landfill of filtered iron ore flotation tailings

KEY WORDS:

Iron ore, filtered tailings, experimental landfill, geotechnical behavior

PAGES: 118
BIG AREA: Engenharias
AREA: Engenharia Civil
SUBÁREA: Geotécnica
SUMMARY:

The mineral industry faces the challenge of ensuring sustainable mining with engineering practices that can reduce the potential damage associated with the operation of geotechnical structures. Based on that, the construction of experimental landfills is considered as an alternative to understand the performance of filtered tailings during compaction. This study addresses the construction of an experimental landfill of filtered flotation iron ore tailings constructed with the purpose of evaluating the behavior of the structure in terms of geotechnical properties and  the material workability for future construction of a filtered tailings pile. The layers were executed in order to present a minimum compaction degree (GC) of 98% and tests were carried out for quality control in each layer. In addition to piezometers installation, geophysical campaign, field tests and collection of disturbed and undisturbed samples were performed for the laboratory tests. The required compaction degree required was achieved with five turns of the road roller and there was no issues related to the operation. There was a decrease in water content during the filtering process resulting in some layers compacted below the optimum moisture content. Tailings was characterized as a fine silty sand, poorly graded and with no plasticity. The saturated hydraulic conductivity obtained in the triaxial tests is 10-3 cm/s and the determination of the retention curve using the filter paper method was adjusted considering the results of the reconstituted samples with a compaction degree of 95% and in situ samples (GC > 98% ). The CID and CIU triaxial tests in the in situ samples demonstrated high shear strengh (friction angle of 37º), a dilatative behavior and without excess poropressure generation. The CIU triaxial tests performed in samples with compaction degree of 95% indicate the generation excess poropressure, therefore this degree of compaction is not suitable for future construction of the tailings dump. The CPTu tests confirm the high shear strength of this filtered tailings, the dilatant behavior and no liquefaction susceptibility. The geotechnical instrumentation demonstrates that the positive pore pressure generation during the landfill construction was very low due to the moisture content below the optimun moisture during compaction.

COMMITTEE MEMBERS:
Presidente - 3132829 - RAFAEL CERQUEIRA SILVA
Interno - 404827 - ANDRE PACHECO DE ASSIS
Externo ao Programa - 1006089 - GERMAN MARCELO MARTINS VINUEZA FREIRE - UnBExterno à Instituição - Gabriel Gomes Silva - UFCAT