Análise numérica da influência de armaduras complementares em blocos sobre duas estacas com cálice embutido e interfaces com chave de cisalhamento

Abstract

This research aimed to analyze the behavior of a reinforced concrete two pile caps with embedded socket and shear keys in the presence of additional reinforcement. A numerical model was developed in the ABAQUS software, based on the finite element method. The numerical models were calibrated and validated based on experimental tests by Barros (2013). A parametric analysis of the models was carried out in two stages, which also included the variation in the compressive strength of the concrete of the pile caps. The first step consisted of varying the steel area and arrangements of the additional reinforcement proposed by Barros (2013). The second stage included the variation in the angle and configuration of the additional reinforcement. It was observed throughout the parametric analyzes that the compressive strength of the pile caps was the parameter that most influenced the load capacity of the models by providing greater resistance to the compression stuts since the models' collapse occurred due to the crushing of the concrete in the struts in the connection region. The results of the first stage showed that the additional reinforcement, originally proposed by Barros (2013), does not influence the load capacity of the pile caps and crack control. The analyzes of the second stage showed that the new proposed configurations A1, A2 and A1+A2 enabled better control of the cracking of the pile caps. Reinforcement A1 acted to control diagonal cracking of the pile caps strut, increasing load capacity between 0.94% and 2.55%, varying according to the pile caps’ compressive strength. The A2 model was more efficient, controlling central cracking and diagonal cracking of the pile caps struts, resulting in an increase in load capacity between 5.31% and 10.19%. The A1+A2 model presented practically a superposition of effects, controlling both diagonal cracking and central cracking. It was the arrangement that provided the greatest increases in load capacity, which varied between 6.77% and 12.48%. Thus, the importance of reinforcement for controlling cracking in pile caps with embedded socket with shear keys is demonstrated., in addition to resulting in better behavior in service and greater durability of the structural element, they can also act by delaying the collapse mechanisms of the pile caps and, thus, increasing their load capacity, as was observed more significantly on models A2 and A1+A2.