On an 8km section of the railway between Èortanovci and Petrovaradin, in Serbia, Tensar International’s geogrid technology enabled essential track reconstruction by Serbian Railways to be completed over low load bearing capacity ground. As well as saving 30% in fill-material costs compared to conventional techniques, the geogrid solution prolonged the service life of the track, speeded up the reconstruction and decreased the track’s long-term maintenance requirements.

The railway section in question was typified by a soil with a moisture content between 22% and 27%, with an adjacent river. This resulted in a low bearing capacity sub-grade unsuitable for rail construction.

The conventional solution recommended excavation of the sub-grade soil, which would have been down to 1m in the most difficult sections, and replacement with a high-quality imported aggregate. However, after consulting Tensar’s design department and following tests using Tensar bi-axial geogrid technology, the Serbian Railways Directorate issued a recommendation for the application of geogrids for railway line reconstruction.

These guidelines were the basis for reconstructing the whole 8km stretch, using more than 35,000m² of Tensar geogrids. As a result, the bearing capacity increased to a sufficient level to meet the load bearing specifications.

By using Tensar technology, the volume of excavation was reduced considerably, and the old ballast could be re-used thus saving 30% in material costs. In turn transport costs were reduced and more rapid work was possible as access was facilitated by using the local materials. This enabled the work to be completed within a very tight time frame, by September 2005, before winter.