Muro de contenção de bloco de concreto reforçado com geogrelhas: um estudo de caso nos sertões de Crateús

Abstract

The execution of Mechanically Stabilized Earth Walls is considered an innovative solution in geotechnical engineering. Recent studies highlight the significant benefits of using geosynthetics in retaining structures, including improved stress distribution and reduced environmental impact when compared to conventional systems. In this context, this study aimed to analyze the technical and economic feasibility of a retaining wall composed of structural concrete blocks reinforced with geogrids, designed for the semi-arid region of the Crateús hinterlands. Based on a literature review, wall and foundation soil parameters were defined, followed by wall design using the limit equilibrium method. The analysis addressed both external and internal stability, considering stress behavior in each reinforcement layer, safety factors for pullout and face-reinforcement connection, along with a comparative cost analysis involving a conventional solution commonly adopted in the region. Three scenarios were evaluated, with wall heights of 5, 10, and 15 meters, to assess constructive and design constraints. Results indicated that the backfill self-weight contributes to reinforcement confinement, as the maximum tensile forces in the geogrids increase with depth. This behavior supports the use of stronger geogrids at lower layers and weaker ones at the upper layers, optimizing overall design costs. Pullout stability also showed increasing safety factors with depth due to vertical stress increase. Conversely, face-reinforcement connection safety factors remained nearly constant, with critical values observed at the top and bottom layers—explained by the dependence of anchorage resistance on effective vertical stress and the influence of active horizontal thrust. Scenario analysis confirmed that the reinforcement length must be at least 50% of the wall height to ensure external stability. Finally, the cost comparison between the MSEW and the conventional system revealed an approximate 50% savings, reinforcing the technical-economic and environmental feasibility of the proposed solution, especially in regions where local soil reuse is possible and cement consumption can be reduced.