SM-3 – Head Race Tunnel and Concreting

SM-3 Head Race Tunnel Work

For our client, Hydro-Quebec, we had the mandate to perform the following work:

• Designing and building a one-kilometre access road to the channel head and water intake canal
• Excavating and concreting the channel head, water intake and 1,000 m SM-3 head race tunnel (equipped with a 329-m surge chamber with an open-cut basin near the generating station)
• Designing, supplying, installing and commissioning weather protection, emergency lighting, water supply and drying systems.

We completed the project efficiently: we excavated 68,000 m³ of rock for the channel head and 190,000 m³ of underground rock for the head race tunnel. We also used 22,450 m² of anchored wire mesh with 9,295 m of bolts to prevent rock chipping and shore up the excavated rock walls.

For the channel head, we used sluice gate guides and debris grills. The project required 9,000 m³ of concrete and 375,000 kg of structural steel.