Análise experimental e numérica sobre a influência de chapas de ligação bloco-estaca no comportamento mecânico de blocos sobre duas estacas metálicas

Abstract

The pile cap is designed as a transition element that transfers loads from the superstructure to the piles. Although widely used, there is no unified calculation method or consensus on the parameters to be used in its design. Typically, the strut-and-tie method is employed for rigid pile caps, while the sections method is used for flexible pile cap. In addition, the limitations of scientific knowledge on the behavior of pile caps on steel piles, together with the scarcity of available technical literature, result in divergence between analytical methods and the absence of standardization. This can lead to incorrect verifications, resulting in oversizing or undersizing of these elements, which can cause material waste or compromise the structural safety of buildings. Considering these issues, this study proposed to investigate the mechanical behavior of pile caps by adding a welded plate on top of the steel piles, referred to as a connection plate. This plate increases the area of the lower nodal zone, reducing stresses in this region. For this investigation, 6 models of pile caps on two I-beam steel piles were fabricated, with variations in reinforcement and connection plate thicknesses. The experimental tests allowed for the analysis of the models' overall behavior, stiffness, and ultimate strength, the deformation of the ties, piles, column longitudinal reinforcements and the concrete in the strut region. The results showed that adding a connection plate to pile caps on steel piles can significantly increase their load-bearing capacity. To further the study, numerical simulations were conducted using ABAQUS/CAE® software, utilizing the experimentally tested models to validate the numerical models and understand the stress flows and mechanical behavior. Through these analyses, the study aims to advance knowledge on the mechanical behavior of pile caps on steel piles and explore ways to optimize them.