Development of a Test Facility for Emergency Spillway Protection

The improvement on actions to ensure the safety of dams is being intensely discussed nowadays. The number of small dams in the world is not accurately known, but it surely is significantly high. In many countries more than 90% of the dams are small, most of which built in earth material and used for irrigation. In 2016, the National Water Agency (ANA) in Brazil verified the existence of 22,920 dams, half of which operate irregularly. Thus, as part of the legalization process, owners call for quick, cost-effective, low-cost solutions to comply with the law. Moreover, hydrological changes have shown the need to update the operating conditions of the dams, such as the increase in the reserved volume and the increase in the discharge capacity of the spillway. ANA found that the problems are in the spillways, which presented erosion and/or deficiency in their operations. For example, a single spillway capable of discharging extreme floods may be economically not viable. Thus, an emergency spillway for the extreme events is an alternative to increase dams safety. The analysis of free surface flows, which occur in pouring structures, is performed through simulations in numerical models and in physical models. The proposal of this work is to adapt a didactic test bench of channel for the study in physical model of emergency spillways covered by special blocks for small dams of earth material. The efficiency of these precast concrete blocks, made with polymer aggregate, coming from the disposal of tires, which are easily found and are a big problem for the environment, will be evaluated experimentally. As part of the tests, the operating limits of this type of spillway will be characterized, aiming to reduce construction and maintenance costs.