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
