DYWIDAG Post-Tensioning Bars Stabilize Brazil’s largest Hydroelectric Power Project

Considered Brazil’s largest hydroelectric power project, the Estreito Dam is one of the most important components of the Brazilian government’s growth acceleration program. The dam is located on the Tocantins River in northern Brazil, bordering the federal states of Tocantíns and Maranhão.

The Estreito Power Plant is a public utility financed with private investments. When fully operational, the plant will generate 1,087MW of power, which is enough electricity to power a city with a population 5 million. For the reservoir, an area of 400 km² is flooded in two federal states, and the reservoir will have a capacity of 5.4 billion m³ and cover an area of 555 km².

The spillway of the dam has 14 20m long spans. For securing the floodgates, a construction method was chosen that allows the assembly of the gate components while water continues to pass through the spillway. In this method, 26 metallic consoles were used as temporary supports for each floodgate during assembly. The metallic consoles were connected to the pillars using 32mm Ø DYWIDAG THREADBAR ^® and prestressed.

Protendidos DYWIDAG supplied more than 3.8km of 32mm Ø St 85/105 DYWIDAG THREADBAR ^® and a total of 1,290 anchorages.They also rented the stressing equipment and provided a full time supervisor for the installation.

Filling of the reservoir started in May 2010, and the first of eight power generating turbines began operating in September 2010. The Estreito Hydroelectric Power Plant is expected to be fully operational by November 2011.