GRP Shafts for Deep Tunnels in Minneapolis
On two recent large diameter tunnels in the Minneapolis-St. Paul area, Wood- bury L73 and Victoria Intercept Sewer Tunnel, HOBAS GRP was the material of choice for both the tunnel and the manhole risers, says Vince Paparozzi, area sales manager for HOBAS Pipe USA. “They were about 23 m deep for Woodbury and 30.5 m on the Victoria project. Since the two-pass-tunnel used fiberglass pipes as the liner, it only made sense to continue the corrosion resistance in the shafts to the surface.”