There are at least 80 specific applications area for geotextiles that
have been developed.However, the fabric always performs at least one
of five discrete functions:
Separation
Geotextiles function to prevent mutual mixing between 2 layers of soil having different particle sizes or different properties.
Drainage
The
function of drainage is to gather water, which is not required
functionally by the structure, such as rainwater or surplus water in the
soil, and discharge it
Filtration
Filtration involves the establishment of a stable
interface between the drain and the surrounding soil. In all soils
water flow will induce the movement of fine particles. Initially a
portion of this fraction will be halted at the filter interface; some
will be halted within the filter itself while the rest will pass into
the drain. The geotextile provides an ideal interface for the creation
of a reverse filter in the soil adjacent to the geotextile. The complex
needle-punched structure of the geotextile provides for the retention
of fine particles without reducing the permeability requirement of the
drain.
Reinforcement
Due to their high soil fabric
friction coefficient and high tensile strength, heavy grades of
geotextiles are used to reinforce earth structures allowing the use of
local fill material.
Protection
Erosion
of earth embankments by wave action, currents and repeated drawdown is
a constant problem requiring the use of non-erodable protection in the
form of rock beaching or mattress structures. Beneath these is placed a
layer of geotextile to prevent leaching of fine material. The
geotextile is easily placed, even under water.