Storm sewer line project
Crossing Length: 1,472 meters
Pipe Material: Reinforced concrete jacking pipe (RCJP)
Total Shafts: 10
Location: AB, Canada
This sewer improvement project was initiated due to the unusually heavy rains that caused flooding and sewer backup in hundreds of homes. The objective of the project was to reduce the risk of storm sewer overflow, as well as basement and surface flooding during high intensity, low frequency rainfalls.
Bothar, as the prime contractor on the project, is wrapping up the completion of a new residential storm water line, including 10 shafts, with tie ins to existing lines and open cuts to dry ponds. This project was executed in a densely populated urban area requiring extensive traffic control and instrumentation monitoring program. Aside from facing extreme Northern Alberta weather conditions, the crew encountered till, sandstone and bedrock during shaft sinking and construction.
Microtunnelling of 1,257m of ID3000mm RJCP in 3 drives & microtunnelling of 215m of ID800mm RCJP in 3 drives. 10 shafts (2 of which are ID11.4m). MTBM used: AVN2500 mixed cutting face.
- Operating in a densely populated urban area (LRT, traffic, shopping, school and residential homes).
- Sinking large diameter shafts into till and sandstone bedrock.
- Tunneling in varying soil conditions under groundwater table.
- High volume vehicle and pedestrian traffic around the site.
- Nearby infrastructure and residential buildings needed to be monitored for any effects from construction.
- Live sewer connections and full catch basins which required bypass pumping.
- Unidentified utilities and abandoned sewer lines.
Operating as the prime contractor, Bothar proposed design and construction of a permanent shaft manhole, using an innovative method, resulting in timely execution and cost savings.
To reduce the risk to any nearby structures and existing infrastructure, Bothar developed and implemented a monitoring program; providing baseline and continuous monitoring during construction.
Prime contractor duties included: Quality Health Safety and Environment management (QHSE), Construction Environmental Management Plans (CEMP), traffic and pedestrian control, utility relocation, civil works, open cut works to install catch basin and catch basin leads, site security, permits, insurance, bonding, muck disposal, tie-ins, bypass and diversions pumping, surface restoration and land reclamation, etc.
The upgrades included upsizing the storm sewers, and installing storage pipe for the storm system. With minimal disturbance to those living and visiting this neighborhood, the community and the client no longer need to worry about flooding and damages to property.