Wick Drains (Prefabricated Vertical Drains, Vertical Strip Drains)
Wick drains, also known as Prefabricated Vertical Drains (PVD) and Vertical Strip Drains (VSD), are a ground improvement technique that provides drainage paths for pore water in soft compressible soil, using prefabricated geotextile filter-wrapped plastic strips with molded channels. A hollow mandrel is mounted on an excavator or crane mast. The wick drain material, contained on a spool, is fed down through the mandrel and connected to an expendable anchor plate at the bottom of the mandrel. A vibratory hammer or static method is used to insert the mandrel to design depth. The mandrel is then extracted leaving the wick drain in place. The wick drain is then cut at the ground surface, a new anchor plate is connected to it and the mandrel moved to the next location. A pattern of installed vertical wick drains provides short drainage paths for pore water, thereby accelerating the consolidation process and the construction schedule.
Wick drains are available from our subsidiary, HB Wick Drains. Contact your local Hayward Baker office for more information.