Description

Underground drainage system design
How are Wick Drains Designed?
The rate of soil consolidation or settlement is controlled by how rapidly the pore water can escape from the soil. The controlling variables are the spacing between the wick drains and the permeability of the soil. The amount of consolidation is independent of whether wick drains are present and is determined by the soil compressibility and the weight of the fill above the wicks. By developing a set of design curves of drain spacing, fill height, and consolidation time, the most economical drain spacing and height of fill can be selected to achieve a given degree of consolidation in a specified time period.

Wick drains, also known as Prefabricated Vertical Drains (PVD), are installed to provide drainage paths for pore water in soft compressible soil. Sunzo is the leading wick drain installer in the China.

Common Uses
Accelerate drainage during surcharge programs
Consolidate tailing ponds and leach pads

Technical Details
The wick drain material is a prefabricated geotextile filter-wrapped plastic strips with molded channels. The drain is fed down through a hollow mandrel mounted on an excavator or crane mast. At the bottom of the mandrel, the wicks are connected to an expendable anchor plate. A vibratory hammer or static method is used to insert the mandrel to design depth. The mandrel is then removed, 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 is moved to the next location. A pattern of installed vertical wick drains provides short drainage paths for pore water, which accelerates the consolidation process and the construction schedule.


Underground drainage system design