Rangeview sanitary trunk project
Client: City of Calgary and Volker Stevin
Location: Calgary, AB
Execution: March 2019- March 2021
Total tunnelling distance: 2.584km
Total tunnelling hours: 1968hrs
Number of pipes installed: 636
OVERVIEW
Bothar was contracted to perform the installation of the 1800 ID – 2160 OD Concrete Jacking pipes for the Rangeview Sanitary Trunk project which will provide wastewater services for a new neighbourhood development in south Calgary. Construction of the new sanitary trunk entailed microtunnelling 2.584km and pipeline installation passing under a busy highway and near a full stormwater retention pond using trenchless method. The Bothar crew worked tirelessly during the COVID-19 pandemic through extreme weather conditions.
CHALLENGES
Construction of three 9.0m diameter segmental shafts to 18m depth in order to install product pipe via microtunnelling methodology. Aside from having to cross under a major throughfare, Deerfoot trail, and alongside a stormwater retention pond with challenging soil conditions varying from sand to a mix of silt to clay pockets, Bothar team microtunnelled in temperatures as low as -35OC.
ACTION
Geotechnical report provided by the client assisted in adapting and customizing the microtunnelling process/method as well as choice of TBM cutting head for the varied soil conditions. Passing under Deerfoot Trail required further pipe plan modification to minimize risk of work and traffic stoppages.
RESULTS
The Bothar team successfully completed the Rangeview Sanitary Tank Sewer project achieving a maximum rate of 56m in a 24-hour period with average tunnelling of 1.3m/hr.
