1 MARCH 2000
a. Application under Track. Geotextiles are sometimes used under the track to provide for filtration
and/or separation of ballast and subgrade or ballast and sub-ballast, or drainage functions. Common
locations for the installation of a geotextile under track are:
(2) Locations with poor subgrade.
(3) When rebuilding track with a history of excessive loss of profile (surface) and frequent track
(4) Turnouts. (See figure 6-18).
(5) Bridge approaches. (See figure 6-19).
Recent industry studies have shown that geotextiles have not always been effective under track. Thus,
before deciding to install a geotextile, a thorough analysis of the site must be done to assure that a
geotextile will accomplish its intended purpose.
Figure 6-18. Geotextile Installation under a Turnout