Estudo sobre soluções de contenções para taludes instáveis

Abstract

In the Castelo Branco quarter, in João Pessoa, Paraíba, two slopes that are located on the margins of kilometer 19 of BR-230/PB suffer with the advance of erosive processes and recurring mass movements, due to an insufficient drainage system and the lack of engineering solutions that promote stabilization to the massif, which would prevent the occurrence of new landslides and mitigate the effects of mass movements in the region. In order to come up with a containment solution that could be adopted by de public administration to stop these slopes’ degradation process, in this study, were performed: a survey of available information about the mass movements historic and interventions in slopes; a topographic survey of the area assisted by drones and already existing projects; field and laboratory tests; and slope stability analysis. As a result of the research, it was possible to verify that, in the area, landslides occur mainly in April, May and June, which coincides with the period of greatest rainfall in the city. From the tests, it was found that the slope soil is mainly composed of sand, which makes it highly susceptible to the occurrence of erosive processes. The stability analysis, in turn, enabled the identification of critical sources along the analyzed section, in which the execution of processes must be a priority. It was found that there is a project to adapt the highway, being executed by the National Transport Infrastructure Department, in which solutions are presented for the slopes studied in this work, which contemplate the slope restoration of one of the slopes and which will lead to the removal of some residences in the nearby communities. In order to allow the permanence of these residences, in view of the direct and indirect costs associated with expropriation, and to reduce the volume of earthmoving, a proposal for an alternative solution was elaborated by a hybrid solution in anchored retaining walls and compacted landfill, complemented by removal of medium and large trees, planting of vetiver grass on the slopes’ face, execution of foot and top channels and use of barbicans.