Underground — South America — Brazil — Tunneling
The Caquende Hydroelectric Power Plant in Brazil : The AT – Pipe Umbrella System demonstrates its Efficiency and Safety
Near the town of Bonfim in the Federal State of Minas Gerais northwest of Rio de Janeiro , a new 4MW hydroelectric power plant is being built on the Macaúbas River : The PCH Caquende .
Once completed , the power plant will feed approx . 18,500MWh of electricity per year into the power supply system . The PCH Caquende consists of 3 horizontal Francis turbines that are operated at an influx rate of 7m ³/ s of water . The concrete dam that forms part of the power plant reaches a maximum height of 2.5m and is 60m long .
Within the scope of construction work , a 350m long single tube inlet tunnel is being excavated . Since the tunnel portal is located in an unstable zone , the Type AT – 76 Pipe Umbrella System was used for pre-support .
Due to the self-drilling installation process , the AT – Pipe Umbrella Support System decreases deformations and increases the stability and safety in the working area .
DSI Underground Brasil supplied the complete AT – 76 Pipe Umbrella System on short notice for the construction of the PCH Caquende . The required system components included the AT – Starter Unit with drill bit , AT – Extension Tubes , injection valves in the injection drillings , several AT – Drilling Adapters , the required drill rods and AT – Grouting Caps .
The pipe umbrella tubes were installed piece by piece and overlapped using conventional drill booms with rotary-percussive rock drills . The general contractor was very satisfied with the fast , self-drilling installation of the pipes and their high directional accuracy during installation . Furthermore , DSI Underground Brasil ’ s specialists supported the jobsite personnel during the professional installation .
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