Banca de DEFESA: EURICO DE LIRA ARAUJO JUNIOR

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : EURICO DE LIRA ARAUJO JUNIOR
DATE: 20/06/2022
TIME: 13:30
LOCAL: Programa de Pós-Graduação em Engenharia Civil on line
TITLE:

Impact of Uncertainty in the Prediction of Settlements on the Redistribution of Efforts and the Safety of Deep Foundations

KEY WORDS:

Settlement behavior; Soil-structure interaction; Group effect in piles; Safety in mat foundation.

PAGES: 257
BIG AREA: Engenharias
AREA: Engenharia Civil
SUMMARY:

Mechanisms such as Soil Structure Interaction (SSI) and Construction Sequence (CS) are increasingly used to the detriment of models that consider columns as fixed node supports. For a correct analysis of SSI e CS it is fundamental a satisfactory prediction of settlements. In the case of mat foundations, this prediction becomes even more complex due the interaction of the pile and the soil, wich can generate group effect. This work aims to: analyse effects of support settlements predictions uncertainties on the migration of efforts in multi-story buildings and their impacts on the safety of mat foundations; analyze the behavior of measured settlements in multi-story buildings and to propose a statistical method that considers settlements as random variables in the construction of effort probability curves. The methods of Meyerhof (1959), Aoki and Lopes (1975), Poulos and Davis (1980) and NBR 6122 (2019) were used to estimate the settlements of 2 reinforced concrete buildings (A and B) whose foundations are constituted by continuous flight auger piles. The Kolmogorov-Smirnov and Shapiro-Wilk tests were applied to the measured settlement samples in order to ascertain whether these values belonged to normal distributions. The foundation safety analysis considered the uncertainties in the settlement prediction and was evaluated in terms of Reliability Index, Failure Probability and Safety Factor. Settlement predictions for the different methods ranged from 1.40 mm to 20.38 mm in one column and from 1.17 mm to 15.57 mm in another. Regarding the measured settlements, it was found that there is not always an increase in the stiffness of the soil-structure set in less rigid conditions columns to the detriment of columns more rigid conditions. The use of ISE based on different settlement estimation methods revealed a great variability both in axial loads (38% reduction and 48% increase in the same column) and in the moments close to the columns (160 times increase in the same column) in relation to the model that considers the supports as fixed. The Shapiro-Wilk test indicated that in more than 90% of the evaluated settlement samples there are indications that the populations come from a normal distribution. The statistical method applied to the measured settlements of Buildings A and B were confirmed through a verification test, proving the validity of the proposed methodology for obtaining random settlements. The consideration of settlement randomness impacts the Reliability Index, Failure probability and Foundation Safety Factor.

BANKING MEMBERS:
Externo à Instituição - MAURÍCIO MARTINES SALES - UFG
Externo à Instituição - PAULO CÉSAR DE ALMEIDA MAIA - UENF
Externo à Instituição - FERNANDO ARTUR NOGUEIRA SILVA - UNICAP
Externo à Instituição - JOAQUIM TEODORO ROMAO DE OLIVEIRA - UNICAP
Presidente - 1413233 - LEONARDO JOSE DO NASCIMENTO GUIMARAES