Burnhamthorpe Water Project C1&C2

Project Highlights

Role: General Contractor

Project Delivery: Design-Bid-Build

Tunnel Equipment: 2ea 1.2m MTBMs, 3m & 2.7m TBMs (Shielded), 3m TBM (Main Beam), 800mm MTBM

Primary Support: Microtunnelling Pipe, Ribs & Lagging, CPP Carrier Pipe

Ground Conditions: Georgian Bay Shale Formation

Project Description

The project included approximately 2200 meters of 1200mm sanitary sewer and 210 meters of 600mm watermain installed my microtunneling. The 1200mm sanitary sewer was installed using a single passed method with RCJP directly installed. The 600mm watermain was installed inside a 1500mm diameter jacked microtunnel CPP with an inside steel liner. The sanitary sewer works required the construction of 6 shafts, each 7.14m diameter, varying in depth from 24m to 30m.

The project also consisted of 3.6km of 3m diameter Tunnel in shale (800m using rockbolts & mesh and 2,8km using ribs & lagging), with a 1500mm carrier CPP being installed within the excavation. The watermain works required the construction of 6 shafts with a diameter of 14.1m with varying depths ranging from 22m to 29m.

The sanitary sewer was excavated using a 1.5m diameter slurry MTBM and the watermain tunnel was excavated utilizing a 3m main beam TBM and a 3m diameter single shielded mixed faced TBM.

All shafts were constructed by ribs/wire mesh/shotcrete in the overburden and rockbolts and plywood in the shale, with the exception of 3 shafts constructed using secant piles for overburden support.

Drive Length: 3600m, 400m & 200m

Diameter: 3m, 1.5m & 1.5m

Contract Amount: $134,071,727

Ground Conditions

All tunnel drives were within the Georgian Bay formation shale with limestone layers reaching strengths up to 230 MPa.