Coxwell Sanitary Bypass Tunnel

Delivered as part of the NTC Joint Venture, this major deep-tunnel project connects the
Ashbridges Bay Treatment Plant to Coxwell Ravine Park. The scope included TBM-driven
tunnel excavation with precast segmental concrete lining, multiple deep cast-in-place anddrop shafts, adit tunnels, and diversion /consolidation sewers, with connections to existing trunk sewers.

• EPB Tunnel Boring Machine (TBM) utilized
• Tunnel length exceeding 10 km
• Complex cast-in-place concrete structures up to 22 m in diameter
• Shaft depths reaching 60 m and shaft diameters exceeding 24 m
• Over 1 km of adit tunnels driven from within the main tunnel using roadheader equipment
• 8 m diameter segmental tunnel lining