Railway Track Work in Section-IV (kms.216.00 to Kms.280.00)Pune-Miraj Doubling Project in Maharashtra – Case study

Ocean Geosynthetics supplied 24240 sq. m of PP geotextile and geogrid (3.0mm/30 kn) for railway track work in Section IV (km 216.00 to km 280.00) of the Pune-Miraj doubling project in Maharashtra. The geosynthetics were used to stabilise the track formation and embankments on the new line.

Product – PP geotextile/ geogrid (3.0mm/30 kn)
Quantity – 24240 sq. m
Location – Pune, Maharashtra (Pune-Miraj doubling, Section IV, km 216.00 to km 280.00)

The project

Railways carry a large share of India’s goods and passengers, and demand on single-line routes has grown with population and trade. Doubling a line lets trains run in both directions without waiting at crossing stations, which cuts journey times and adds capacity. The Pune-Miraj route was taken up for doubling for this reason, and Section IV covers the stretch from km 216.00 to km 280.00.

More trains mean more cyclic loading on the track and on the ballast and formation beneath it. The track bed needs stability, drainage and filtration, ballast and slope reinforcement, and stronger embankments. Railway builders increasingly use geotextiles and geogrids to provide these economically.

Problem

Ballast and sub-ballast do several jobs in a railway line: they drain water away from the track, stop subgrade soil from moving up into the ballast, and spread the stress from passing trains onto the soil underneath.

With continuous use, the ballast wears and deforms. Fine soil from the formation is pumped up into it under repeated loading, especially when the formation is wet, and fouled ballast drains poorly and cannot hold the track geometry. The result is track misalignment, high maintenance costs and speed restrictions.

These problems, seen on earlier railway projects, led to geogrids and geotextiles being specified for the new track.

Solution

On the Pune-Miraj doubling, the Ocean Geotextiles and Ocean Geogrids were used for:

• Separation and filtration: the PP geotextile sits between the formation soil and the blanket or ballast layer. Water drains through it, but fine soil cannot migrate up into the ballast.
• Drainage: the geotextile lets water leave the formation, so it does not soften under the track.
• Ballast and sub-ballast reinforcement: the geogrid interlocks with the granular layers and restrains them from spreading sideways under train loads.
• Embankment reinforcement: geogrid layers within the compacted fill help embankments and slopes resist sliding.

Geosynthetics used this way give the track more stability and reduce maintenance over the years, which is why they have become a durable, cost-effective answer to the problems of earlier railway projects. For Indian Railways, geosynthetics in track formation are specified through RDSO guidelines. See also the Talegaon and Khadki railway project near Pune.