Análise da zona de perturbação causada pela instalação de estacas helicoidais em solo arenoso

Abstract

The present article presents a study on the characteristics of the zone of disturbance caused by the installation of a helical pile in a sandy soil. The depth reached after installation varied between 2.37 and 2.77 m. In this study, penetration tests with the use of dynamic cone penetrometer (DCP) and radargram surveys using ground penetration radar (GPR) were performed. The DCP tests were performed before and after the installation of a helical pile in three different locations, aiming to evaluate the effects of the pile installation by measuring the soil resistance to penetration. With the penetrometer results it was possible to determine a zone of influence equivalent to approximately 3 times the diameter of the largest plate of the pile, within which it is possible to visualize a significant reduction of the resistance of the soil, caused by the installation of the pile. The GPR survey shows a region between the surface and the top helical plate, with a diameter similar to that of the largest plate, where the installation process promoted a clear change in the electrical conductivity of the soil. The results suggest that the passage of the plates during the installation process left the soil inside this region less dense than its surroundings.