Banca de DEFESA: DIDONEY FERNANDES VILHETE

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : DIDONEY FERNANDES VILHETE
DATA : 08/08/2017
HORA: 07:00
LOCAL: A DEFINIR
TÍTULO:

BACK ANALYSIS OF AÇU DAM UPSTREAM SLOPE FAILURE AT THE END OF THE CONSTRUCTION PERIOD


PALAVRAS-CHAVES:

Computational analysis, failures investigation, slope stability, shear strength, probabilistic analysis, Monte Carlo simulation.


PÁGINAS: 97
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Civil
SUBÁREA: Geotécnica
RESUMO:

The risks associated with dam failure are high. Problems of instability involving this frameworks bring catastrophic consequences to the society. The Açu dam is a geotechnical embankment with significant importance in the Northeast, mainly in Rio Grande do Norte state. It is the largest dam in the state and has gained prominence in the national and international literature with the slice of the upstream slope at the end of the construction period. In cases of failure, back analysis is a reliable and economic technique to calculate the shear strength parameters of the soil in order to avoid similar cases. From the evaluation of strength data available in the academic environment, this work had as purpose to analyze the failure occurred to obtain the average shear strength parameters of the black clayey material that constituted the Açu dam core before the accident occurred. In the first stage of the work the slope stability of the dam was analyzed and in the second stage the deterministic and probabilistic back analysis. The analyzes were performed in Slide 7.0 belonging to Rocscience platform. The results were compared to the data available in Mello (1982); Penman (1985) and Rocha (2003). At the end of the research it was possible to define the possible average shear strength values of black silt clay and to establish the causes and mechanisms of dam failure. Stability analyzes showed that the slope would fail with strength parameters of the black silt clay in the saturated condition, with values of probability of failure ranging from 60 to 97% between the equilibrium limit methods used in the analyzes. Finally, the cohesion and the friction angle value obtained at the instant of failure in the deterministic back analysis for black silt clay was cu=47.1 kPa and ϕu=0º. In the probabilistic back analysis the cohesion and the friction angle value obtained at the instant of failure was cu=33,8 kPa and ϕu=3,1º, with a probability of failure of 52,7%. With this, it is concluded that the Açu dam upstream slope failure occurred because of errors of strength parameters of the clay soil adopted in the design accompanied by the poor compaction and loss of the soil strength due to the excess of poropressures generated during the construction.


MEMBROS DA BANCA:
Presidente - 1149451 - OLAVO FRANCISCO DOS SANTOS JUNIOR
Interno - 1692497 - OSVALDO DE FREITAS NETO
Externo à Instituição - FRANCISCO CHAGAS DA SILVA FILHO - UFC
Externo à Instituição - RAIMUNDO LEIDIMAR BEZERRA - UEPB
Notícia cadastrada em: 31/07/2017 11:11
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