Wick drains (also referred to as Prefabricated Vertical Drains or PVD), are used in soft, compressible soil to allow drainage tracks for pore water.
- Accelerate drainage during surcharge programs
- Consolidate tailing ponds and leach pads
Wick drains consist of a geotextile filter wrapped plastic strip with moulded channels that allow water to travel to the ground surface. Wick drains are typically installed prior to placement of a temporary fill load to accelerate the consolidation of compressible soils.
During installation, a hollow mandrel that is mounted on an excavator or crane mast has a drain fed down it. At the bottom, an expendable anchor plate is used to connect the wicks. Then the mandrel is inserted to the designed depth using a vibratory hammer. The wick drain is left in place when the mandrel is removed from the ground. At the ground surface, the wick drain is cut and connected to a new anchor plate. This process is repeated in many locations over the construction site.