Proposta de previsão da capacidade de carga à tração de estacas tipo hélice contínua em solos granulares

Abstract

Foundations projects must present security measures concerning the structural element and soil-structure system failure and acceptable displacements. In buildings it is very common to have foundations which are only subjected to compressive loads, however, in many of them, the foundations are submitted to uplifting forces, thus it is also necessary to verify the safety conditions regarding uplift capacity. In this context, this article evaluates the applicability of specific and non-specific methods for estimating the uplift bearing capacity of continuous flight auger piles in granular soils. In addition to that, a method was developed in order to estimate the ultimate uplift capacity of these pile types. In order to so, this research was based on 97 Standard Penetration Tests (SPT), and 12 continuous flight auger piles in granular soils subjected to the uplift forces. Among the evaluated literature methods, the specific method that presented the best agreement was Meyerhof and Adams (1968), and the non-specific one was Meyerhof (1953), both with approximately 65% higher values, in average, than the reference values and with great scatter. On the other hand, the developed method presented good agreement and lower scatter, establishing an alternative for the determination of uplift bearing capacity of continuous flight auger piles in granular soils.