Banca de DEFESA: DAVID ESTEBAN DIAZ TAQUEZ

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : DAVID ESTEBAN DIAZ TAQUEZ
DATA : 30/03/2017
HORA: 09:00
LOCAL: Auditório do CTEC
TÍTULO:

Susceptibility to the Occurrence of mass movements and evaluation of the stability of cliffs under unsaturated condition: case study in the center of launches from Barreira do Inferno – Brazil


PALAVRAS-CHAVES:

Susceptibility evaluation, Shear Strength, unsaturated soils, cliffs.


PÁGINAS: 30
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Civil
SUBÁREA: Geotécnica
ESPECIALIDADE: Mecânicas dos Solos
RESUMO:

The aim of this research is to evaluate the susceptibility conditions to the occurrence of mass movements and slope stability of the studied area using the method of Strength Reduction Method ou SRM, on unsaturated conditions in the Northeast of Brazil. For the analysis of the susceptibility to the occurrence of mass movements, the methodology called the Analytic Hierarchy Process was used along with the GIS geographic information systems. In order to determine the resistance parameters of the soils, triaxial compression tests were carried out under saturated conditions CU and triaxial compression tests CW were performed for the residual moisture condition. For the determination of soil retention curves, the filter paper method was considered, equations by Chandler et al. (1992), and the adjustment of the retention curves developed by Van Genuchten (1980). From the results of the triaxial tests, the prediction of the shear strength of the unsaturated soils was performed using the hyperbolic model proposed by Vilar (2007). Then, from the susceptible sections to the occurrence of mass movements and the resistance parameters of the studied soils, analyzes of slope stability were applied with the intention of quantify the safety factor of the same. The method used in the stability analyzes was the SRM, implemented in the OPTUM Software, considering different saturation conditions, as follows: soil under natural field saturation condition, soil with 50% degree of saturation, and finally Completely saturated soil. The analysis also took into account the presence of layers of cemented soil and traction cracks present in the upper part of the cliff. The slope was divided into three sections with predominant soils, which were positioned at the base of the intermediate section, and at the top of the cliff, called soil-1, soil-2, and soil-3 respectively. These soils were characterized as clayey sand (SC), silty sand (SM) and poorly graded sand (SP). As for the retention curves, the three soils present bimodal behavior, typical of soils with granulometry of material with micropores and macropores. Finally, the results obtained from these numerical analyzes were initially related to the model of susceptibility produced from the AHP-GIS methodology, concluding that this model is in good agreement, evidenced by the results of the numerical analysis and by the vestiges of Movements observed in the field. The results of the numerical analyzes were also related to the types of mass movements, presenting as an outcome that both geomorphological factors and degrees of saturation result in different types of movements for the characteristic sections of these geomorphologies (cliffs). Verifying in this way the movements suggested in the studies of Santos Jr (2004) and Souza Junior (2013), where three types of profiles with different morphologies and their possible mass movements, toppling, fall of blocks and landslides were related.


MEMBROS DA BANCA:
Presidente - 1692497 - OSVALDO DE FREITAS NETO
Interno - 1222082 - ADA CRISTINA SCUDELARI
Interno - 1149451 - OLAVO FRANCISCO DOS SANTOS JUNIOR
Externo à Instituição - ROGER AUGUSTO RODRIGUES - UNESP
Notícia cadastrada em: 21/03/2017 14:02
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