Banca de DEFESA: Fernando Feitosa Monteiro

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : Fernando Feitosa Monteiro
DATE: 14/07/2023
TIME: 08:30
LOCAL: TEAMS
TITLE:

BEHAVIOR OF BORED PILES EQUIPPED WITH THE EXPANDER BODY SYSTEM IN TROPICAL SOILS

KEY WORDS:

BEHAVIOR OF BORED PILES EQUIPPED WITH THE EXPANDER BODY SYSTEM IN TROPICAL SOILS

PAGES: 415
BIG AREA: Engenharias
AREA: Engenharia Civil
SUBÁREA: Geotécnica
SUMMARY:

The evolution of construction has resulted in increased loads on foundations, making pile foundations the most commonly used solution. The Expander Body (EB) technology was introduced to improve the load capacity of piles and reduce uncertainties in the installation process, but in Brazil, the lack of scientific studies limits the design of these foundations. This thesis aims to analyze the mechanical behavior of bored piles equipped with EB technology, subjected to axial compression and uplift loads. Static load tests were carried out on conventional bored piles and bored piles equipped with EB technology at the Experimental Field Annex of the University of Brasília. The thesis addresses aspects related to the applicability of methodologies for predicting bearing capacity and displacement of piles, as well as the uplift versus compression behavior of piles equipped with EB technology. Comparative analyses of bearing capacity of EB-equipped piles and conventional piles are also presented, as well as numerical studies of load transfer mechanisms and failure surfaces of piles. Finally, load capacity coefficients are proposed for methodologies of bearing capacity prediction for EB-equipped piles and conventional bored piles based on lateritic soils. It was found that piles equipped with EB technology showed a load capacity gain of 32 to 40% in compression and 30% in uplift compared to bored piles without this technology. Displacement estimates were more consistent and accurate when obtained from deformation modules from in-situ tests compared to estimates from laboratory tests. For lateritic, collapsible, and unsaturated soils, frictional resistance ratios to compression and tension ranging from 0.86 to 0.98 were observed for bored piles equipped with the EB technology. Piles equipped with EB technology showed superior load capacity compared to other deep foundation construction methodologies, except for caisson foundations. The theoretical curves used to simulate EB expansion showed a good fit, with determination coefficients R² greater than 0.90. The numerical analyses were successful in comparison with the experimental curves, with correlation coefficients greater than 0.90. It was found that the failure surface for uplift piles resembles a curvilinear surface tangential to ground level, while for compression piles, it assumes a shape similar to that of a logarithmic spiral curve.

COMMITTEE MEMBERS:
Interno - 2517970 - GREGORIO LUIS SILVA ARAUJO
Interno - 2161425 - JUAN FELIX RODRIGUEZ REBOLLEDO
Externo à Instituição - Paulo José Rocha de Albuquerque - UNICAMP
Presidente - 1122864 - RENATO PINTO DA CUNHA
Externo à Instituição - Renato Resende Angelim - UFG