Canal Lining | Central Vancouver Island, Canada
CC used to line a large
diversion channel
Project Overview
In August 2016, over 11,000m2 of Concrete Canvas® (CC) GCCM was installed as a protective liner for a large diversion channel at an underground zinc and copper mine on Central Vancouver Island, Canada. The diversion channel, which conveys clean water from the hillside above to a lower creek, was originally lined with shotcrete but the material had begun to degrade over time. It was recommended that the diversion channel should be enlarged and realigned to effectively handle the high-water volume and velocities.
Solution
Alternative options such as replacement shotcrete were considered, however Concrete Canvas® was specified due to its ability to cope with high water velocities, its ability to accommodate variance in profile and the ease of repair if future damage occurred due to falling trees or large boulders from the above hillside. Since the water was diverted away from the channel during installation, the speed of installation was key as the diversion pipes wouldn’t be able to handle the high-water volume expected to begin in early October. The use of CC meant measures could be in place much faster than using conventional concrete or shotcrete.
The channel was designed to handle water velocities of up to 20m/s with slopes as steep as 16% and 20% in some sections.
Design & Installation
- CC8® Bulk Rolls specified
- Trees and vegetation removed, channel profile excavated
- Gravel sub-drainage layer installed with discharge points into secondary channel
- Transverse layup
- Perimeter edges secured in anchor trenches
- Screwed overlap joints
- Intermediate anchors installed to resist hydraulic shear
- Hydrated using a water truck
Summary
The installation took 6 weeks to complete with an average crew size of 6 men and daily temperatures up to 34°C. The client was satisfied with the product and the minimal amount of specialist training or equipment required. In addition to this, the speed of installation meant the project was completed before the heavier precipitation arrived at the mine in early October which may have caused significant project delays.