Estudo comparativo em modelo reduzido do uso de enrocamento e geomembrana em proteção do talude de montante de barragens de terra

Abstract

In dams, ensuring safety is a key factor in construction and operation, seeking to avoid possible accidents that consequently generate environmental risks and other damages. One of the main factors that cause these accidents are poorly designed dams, such as the lack of protection on the slopes of these dams, which should withstand large volumes of precipitation and impacts caused by natural phenomena, such as wind, which generates waves, in the reservoir, thus causing pathologies on the upstream slope due to their impact. The present work aimed to address the use of geomembrane as protection of the upstream slope of an earth dam, in order to avoid erosion on the slope, caused by the impact of waves formed in the reservoir. For this, a reduced physical model of an earth dam was prepared, in which three simulations were performed, namely: reduced physical model of a dam without rip- rap protection, reduced physical model of a dam with rip-rap protection under the use of rockfill and reduced physical model of the dam with protection of the upstream slope using geomembrane. In the three simulations carried out in the reduced model, waves in the reservoir with a certain frequency and height were also simulated. With that, a manual device was elaborated to generate the waves inside the reservoir. Finally, with the results obtained in the three simulations in the reduced model, a comparative analysis was carried out, verifying that the reduced physical model of a dam without rip-rap protection, proved to be more susceptible to the erosion process due to the impact of waves. In contrast, the use of geomembrane as a slope protection material proved to be efficient, with no pathologies linked to erosion and removal of granular soils being registered.