Geosynthetic applications in high-speed railways: a case study

A high-speed railway project for trains with speeds of 160–180 km/h was recently completed in Malaysia. An array of geosynthetics such as biaxial geogrids, non-woven geotextiles and woven geotextiles were extensively used in the project primarily for separation, filtration and reinforcement purposes. The geosynthetics were particularly used at locations of high embankments underlain by soft clays and loose sands. Ground improvement using geosynthetics in the project primarily included geogrid-reinforced piled embankments with individual pile caps, geogrids at bridge approach transitions, geogrids for ground treatment beneath culverts, geogrids for culverts supported by stone columns, woven geotextiles for cement column works, non-woven geotextiles for excavation works, non-woven geotextiles at the top of the railway subgrade layer, non-woven geotextiles for temporary retaining walls and non-woven geotextiles for slope protection works. This paper provides a detailed insight into the design and implementation of ground improvement using geogrids and geotextiles in this case study project, with a focus on the geogrid reinforcement design of piled embankments with individual pile caps. The use of geosynthetics in the various railway applications in the project was found to provide safe and cost-effective solutions to the various geotechnical engineering challenges encountered.