A laboratory investigation on the advancement of railway ballast behavior using artificial inclusions

Abstract

Ballasted rail tracks are the most popular and conventional rail track foun- dation system primarily consists of ballast as a major portion by weight and volume. Ballast is a highly angular, coarser material with high bearing capacity, shear strength, and non-water absorbent, which is obtained by crushing rocks. The ballast layer absorbs and widely distributes the moving train loads from sleepers to the ground. With time, the ballast is deteriorated because of frequent cyclic and impact loads from train movements, which ended up with high-cost maintenance. Artificial inclusions are renowned remedial action to the above-mentioned issue. In this laboratory-based study, the effect of rubber pads and geogrids on the shear and deterioration behavior of ballast was evaluated by conducting large-scale direct shear tests under 30, 60, and 90 kPa normal loads with a shearing rate of 4 mm/min. Based on the experimental results, a combination of shock mats and geogrid is suggested which enhanced the stress, dilation, and deterioration behavior of railway ballast.