Estudo da distribuição dos reforços em muros portantes de solos reforçados com geossintéticos

Abstract

Geosynthetic-reinforced structures have been applied to compose bridge abutments carrying loads from bridge structures. In this application, reinforced soil structures have been constructed using reduced spacing between geosynthetic reinforcements in comparison to the conventional reinforced soil walls. Therefore, there are many issues when using this technique that must be assessed to provide cost saving and proper performances mainly regarding the reinforcement arrangements inside the reinforced soil mass. The present study evaluates the performance of a load-carrying geosynthetic reinforced soil structure using different arrangements of reinforcements. A numerical simulation using a finite element modeling was conducted with the computational program Plaxis 8.2. Different methods for the stiffening of the GRS structure were adopted including: (1) use of significantly rigid geosynthetics with relatively high vertical spacing between reinforcements; (2) use of reduced spacing between reinforcements but with less rigid reinforcements; (3) use of secondary reinforcements with reduced lengths. In addition, the use of non-uniform configuration of reinforcements were also assessed in the present study. Results show that using rigid geosynthetics with high vertical spacing led to an improvement on the structure performance but limited to a certain value of secant stiffness. Using a remarkably high stiffness geosynthetic not necessarily resulted in very low settlements and deformation. The use of reduced vertical spacing between relatively flexible reinforcements demonstrated a significant improvement in performance similar to that obtained with larger spacing but higher reinforcement stiffness. However, this approach led to lower levels of loads mobilized by reinforcements. Regarding the use non-uniform configurations of reinforcements, the use of high stiffness reinforcements at a third of the structure height (from the top) was sufficient to reduced settlements and lateral deformations to acceptable levels. On the other hand, the reduced vertical spacing must be applied to the half of the height. However, use significantly lower stiffness of geosynthetic reinforcement, leading to a considerable cost savings. The use of secondary reinforcements replacing the reduced vertical spacing technique (half of wall height) demonstrated to be similar efficient to improve the structure performance.