Banca de DEFESA: CAMILLA MARIA TORRES PINTO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : CAMILLA MARIA TORRES PINTO
DATA : 13/05/2021
HORA: 13:30
LOCAL: online
TÍTULO:

STUDY OF THE MECHANICAL BEHAVIOR OF RIVER SAND REINFORCED WITH FIBERS 

PALAVRAS-CHAVES:

Reinforced soils; Soil/fiber interaction; Triaxial tests.

PÁGINAS: 78
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Civil
RESUMO:

Often, in its natural state, soil does not meet the minimum technical requirements for use in civil engineering projects. To overcome these deficiencies, several techniques are used to improve and reinforce soils for use in engineering. Soil stabilization techniques are based on steadily improving its original properties, through mechanical, chemical or physical interventions. One of the possible reinforcement techniques that can be used consists of adding fibers to the soil in natura, forming composites with greater resistance to shear and tensile strength. Although there are numerous projects and studies done on soil/fiber composites, discrepancies are still found regarding the influence of the main variables studied, in addition to the existing constitutive models and published works with a view of simulating their mechanical behavior. With this in mind, this research sought to evaluate how the inclusion of polymeric fibers would act to improve the shear strength of river sand and to test a model initially developed for MSW, adapted from Machado (2002) to reproduce the mechanical behavior of the reinforced sand. For this, triaxial tests of the consolidated drained type (CID) were carried out on natural sand and on sand/fiber composites, with the contents of 0.5% and 1.0% of fiber and lengths of 12.5 mm, 25 mm and 51 mm, in duplicate, with confining stresses of 50, 100, 200 and 300 kPa and different stress paths. The reinforcement with fibers promoted significant changes in the mechanical behavior of the sand. The principal verifications were the increase of resistance to the shear of the soil and the identification of the main factors that influenced the sand/fiber interaction: length and fiber content, and confining stresses, which increase the resistance of the soil the greater they are, up to a certain limit. For this study, the fiber content of 1.0% was verified as limiting the use of the composite in the field, without compromising its workability. The hydraulic conductivity of the soil was not altered with the inclusion of fibers, though the volumetric variation underwent some changes, with a tendency to decrease expansion to greater lengths of fiber and soil confinement states. The composite of Pf = 1.0 % and L = 51 mm was obtained as the optimum mixture, which provided an increase of 15.9 kPa in the sand cohesion and 11.2º in the friction angle. The constitutive model adapted from Machado (2002) was able to satisfactorily predict the mechanical behavior of the reinforced sand.

MEMBROS DA BANCA:
Externo(a) à Instituição - MEHRAN KARIMPOUR FARD
Interno(a) - 1299309 - MIRIAM DE FATIMA CARVALHO MACHADO
Presidente - 1219972 - SANDRO LEMOS MACHADO