Canal Lining | Kolwezi, Democratic Republic of Congo (DRC)
CCX-M® chosen for fast, erosion control protection
Project Overview
In June 2022, CCX-MAT® (CCX-M®) was installed to canalise pumped water from settling ponds to a river outlet in Kolwezi, Democratic Republic of Congo. Mining operations the mine are mainly carried out underground.
Due to the high water table and prevalence of subsurface water, continuous pumping is required to ensure safe and favourable working conditions. This underground water is pumped into settling ponds which allow sediments to settle prior to canalising to the local river outlet – with the settling ponds to the river outlet being approximately 4km long.
Solution
To ensure that no water permeated back into the mine as well as protect the substrate from erosion, a lining solution was required. In addition to the pumped water, the canal needed to have the capacity to drain stormwater collected from the catchment above ground. As the subgrade running the length of the canal are lateritic the flow rates in which the canal would be operating under would have caused the soil to erode but also allow the water to permeate back into the mine.
A number of lining solutions were considered including a geomembrane underlay with poured concrete, shotcrete or riprap protection. However, due to the scale of the canal and proximity to the rainy season, a fast and effective solution was needed. Due to the canal being used to divert pumped water as well as storm water, the lining solution needed to withstand and sustain flow rates of up to 6m/s as well as abrasion caused by sediment accumulated by storm water runoff. CCX-M® was chosen as the prefered lining solution due to it being rapid to install – with very little need for a large workforce and plant.
CCX-M® was also chosen for the project due to the material being able to withstand significant flow rates, protect the canal from any erosion and mitigate any water from permeating the soil.
Design & Installation
- CCX-M® Bulk Rolls specified
- Canal excavated and graded into a uniform profile
- Transverse layup
- Perimeter edges secured within anchor trenches
- Round head pegs were installed through the underlap of each joint at transition from side slope to invert.
- Overlapped CCX-M® was thermallly bonded and screwed
- CCX-M® hydrated 3 times (at 30 minute intervals) to prevent premature curing during hot weather conditions
Summary
Due to the speed and ease of application, CCX-M® was installed at an average rate of 10 rolls (950m2) per day with a team of 10 installers. The installation team was spilt into teams each designated by task which involved laying, jointing, fixing and hydrating.
The project has been deemed a significant success by both the client and the EPCM contractor, DRA. This has resulted in the specification of CCX-M® for significant additional scope on the mine as well as consideration for other applications.