Análise experimental e numérica do comportamento de estacas curtas instrumentadas em solo de Uberlândia (MG)

Abstract

In this research, the behavior of bored pile foundations when placed in tropical soils of Brazil, particularly in soils with collapsible behavior in the region of Uberlândia - MG, was investigated. For this purpose, two instrumented and identical bored piles were installed, with a useful length of 6 meters and a diameter of 25 centimeters, in order to evaluate their performance. The piles were subjected to static and slow load tests (SML) in compression and tension, with the soil under in situ and flooded conditions. Subsequently, two- dimensional and three-dimensional numerical analyses were performed to validate a finite element numerical model that will allow for more detailed analyses of soil-structure interaction. Additionally, these results were compared with those of other authors’ bored piles in the same experimental field, in order to establish consolidated average parameters and to evaluate the performance of semi-empirical methods for estimating load capacity and settlement consolidated in the technical environment. Based on the results of this research, it was found that the unit lateral friction in tension exceeded more than twice the same parameter obtained in compression. The load transfer demonstrated an increasing participation of the pile tip in the load capacity as the loading stages advanced, explained by the presence of heterogeneous material in the region. Furthermore, it was observed that the soil flooding process led to approximately 50% decreases in the pile’s load capacity in compression compared to the in situ condition. Regarding load capacity estimation methods, Philipponnat’s method (1976) showed the best performance in compression, Meyerhoff’s method (1973) showed the best performance in tension, and Poulos & Davis’ method (1980) was the most effective in estimating settlements.