Análise experimental e numérica de radier estaqueado isolado com uma estaca em solo tropical na condição in situ

Abstract

In this research, an analysis of the behavior of foundations subjected to axial compression was conducted through static and slow load tests. The tests were performed on prototypes of single piles and single piled raft foundations (pile cap with pile) in the Uberlândia region, Minas Gerais, Brazil. The region predominantly features silty-clayey sand soil. For the study, two mechanically excavated bored piles were constructed, each with a length of 5 meters and a diameter of 0.25 meters. A pile cap with a diameter of 1 meter and a height of 0.20 meters was constructed on one of the piles. The piles were instrumented at various depths, allowing for an analysis of the load distribution mechanism between the pile and the pile cap, as well as a comparison of load transfer along the length of the piles. The results obtained from the instrumentation readings enabled the evaluation of the behavior of the prototypes. To achieve this, a finite element numerical model was employed using the RS2 software from Rocscience to validate the results and enable the extrapolation of the conducted numerical analyses. It was observed that the single piled raft foundation (pile cap with pile) exhibited a 10% increase in total bearing capacity compared to the single pile. It was also noted that the pile cap absorbed 58% of the total applied load on the foundation, while 42% was supported by the pile. The numerical results indicated that, in the single piled raft foundation, the pile did not prevent the formation of a stress bulb. However, this phenomenon resulted in minimal skin friction of the pile in the region. On the other hand, the part of the pile connected to the pile cap acted as a monolithic structure, increasing stiffness, and consequently, bearing capacity, while also reducing settlements