Shear behavior and Permeability of rail track ballast fouled by the infiltration of finer particles

Abstract

Ballasted track is the traditional and widely used railway track system in many countries due to its numerous benefits. The ballast layer consists of uniformly distributed coarse granular material that acts as the main load-bearing component of the track while facilitating better drainage. The ballast fouling is one of the major issues in ballasted tracks where the voids of the ballast layer fill with fine particles generated from ballast degradation under repetitive train load and from various other sources. Ballast fouling affects the shear strength and drainage properties of the ballast layer which finally leads to track instability. A better understanding of the effect of fouling material on shear, degradation and permeability behaviour of railway ballast is imperative to maintain track performance. Also, the full scale simulation of large-size granular materials at the laboratory through large scale testing facilities is important to capture the real behaviour of railway ballast. Therefore, this paper explores the results of large-scale direct shear and permeability tests carried out at the laboratory to analyze the shear, degradation and permeability behavior of railway ballast fouled with finer particles.