A laboratory study on improvement of railway ballast and formation using geosynthetics
The classical railway track basically consists of a flat framework made up of rails and sleepers, which are supported on ballasted track formation. Ballast particles breakdown and deteriorate progressively under heavy cyclic rail loading. Moreover, excessive consolidation settlement and progressive shear failure may occur in soft track formation under repetitive stresses. In order to rectify these problems, frequent maintenance operations are generally required in ballasted track. In order to minimize the deterioration of track substructure and also to reduce maintenance cost, the use of various types of geosynthetics including recycling of waste ballast have been studied in the laboratory. The prospective use of three types of geosynthetics (i.e. geogrids, geotextiles and geocomposites) in enhancing the performance of fresh and recycled ballast has been examined. The aspects of deformation and degradation of ballast under cyclic loading have been studied using a large-scale prismoidal triaxial rig. The research findings reveal that recycled ballast stabilized with geosynthetic reinforcement has a good potential for resilient track construction and for reducing the cost of track maintenance. The experimental findings may be beneficial to the railway engineers and encourage them to upgrade current tracks based on these innovative techniques.