- Laying of the geotextile over the sand layer
without any folds or wrinkles (photo 6).
- Spreading of a thin layer of sand (approximately 50 mm thick)
over the geotextile (Photo 7).
- Installing the geogrid over the second layer of sand (photo
8).
- Placing and compacting cleaned ballast over the geogrid
(photo 9).
Performance
Approximately two years has passed since the completion at the
rehabilitation. As per the feed back from NF Railways, any significant ballast
sinking problem has not been observed in the location treated with geogrids and
geotextiles and there is an appreciable improvement in the track performance.
Taking note of the success of this trail, NF Railways rehabilitated another
stretch using the same materials and technique with satisfactory results. An
inspection of the site in the first week of June 2008 showed that the condition
of the treated portion of the track is quite satisfactory.
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