CARGA DE RUPTURA DE ESTACAS ESCAVADAS A SECO COM ANEIS POR MÉTODOS DE EXTRAPOLAÇÃO DA CURVA CARGA X RECALQUE / LOAD BEARING CAPACITY OF BORED PILES WITH RINGS OBTAINED BY THE METHODS OF EXTRAPOLATION OF THE LOAD-MOVEMENT CURVE

The demand of large buildings in the uptown area of Maceió-AL, in Brazil, made the development of new techniques to perform deep foundations in its particular type of soil, composed of sediments from Brazilian Journal of Development Braz. J. of Develop., Curitiba, v. 6, n. 11, p. 84384-84390, nov. 2020. ISSN 2525-8761 84385 Barreiras Formation. Dry bored piles, commonly used in other regions of Brazil, such as the southeast and midwest, generally have relatively high productivity, they do not produce vibrations and use few workforce, but they also have low resistance due to enforcement proceedings. Dry bored piles with rings were developed in order to increase the capacity of this type of foundation, reduce settlements and generate savings. The rings are executed with a part called "pointer" coupled to the auger, which enlarges the shaft diameter along the perforation in determined depths. The capacity values presented in this paper were obtained from methods based on the extrapolation of the curve "stress vs. settlements "for two piles: one dry bored with rings and one without them Based on the results measured, we could conclude that, in this particular situation, the rings increased the total shaft resistance in around 55% when compared to traditional dry bored piles without rings.