Análise Numérica da Estabilidade de Taludes Empregando Estacas como Elemento de Reforço

Abstract

In this master's thesis, the stability of slopes reinforced with piles is analyzed considering the statistical variability of the geomechanical parameters of the soil and geometric parameters and position of the piles. Situations were modeled with variation of the reinforcement characteristics (position of the pile on the slope, length, diameter and spacing between pile’s axes). The stability analysis of the pile-reinforced slopes is evaluated from the results of the safety factors in deterministic and probabilistic terms and from the probability of failure. The behavior and variation of the safety factor with the implementation of reinforcement in different situations and soil conditions was analyzed. The behavior of the pile as a reinforcement element and the massif’s answer is evaluated from a 2D finite element model, in order to obtain the mechanical behavior of the rigid element in the face of the stresses due to the mass movement of the slip surface. For that, theoretical methods and computational tools were used in the analyzes, using the Slide and RSPile softwares, which use the limit equilibrium method to verify the slope stability and the p-y curves to analyze the piles, respectively. Complementary analyzes under the stress-strain aspect were carried out using the RS2 software, which allows to obtain the behavior of the massif and the action of the stresses on the reinforcement element. The displacements and efforts at the pile were also analyzed. It was concluded that the increase of the pile’s diameter and the decrease of the pile’s spacing contributes to a better slope stability; that the best position for the pile is near the top of the slope and that the factor of safety increases as the pile’s length increases but it exists a minimum length for witch the pile mobilizes the stresses in the slope and a maximum length for witch increasing even more the pile’s length doesn’t result in a better stability. The displacements that resulted from the analysis with FEM and from de p-y curves were both admissible according to the literature.