Figure 6-18. Geotextile Installation under a Turnout

CEMP-E

TI 850-02

AFMAN 32-1125(I)

1 MARCH 2000

11. GEOTEXTILES.

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:

(1) Highway-railroad grade crossings.

(2) Locations with poor subgrade.

(3) When rebuilding track with a history of excessive loss of profile (surface) and frequent track

maintenance requirements.

(4) Turnouts. (See figure 6-18).

(5) Bridge approaches. (See figure 6-19).

(6) Rail crossings.

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

6-26