ABSTRACT
Regular inspection and maintenance of railway track is always a major task for the rail industry. Ballast fouling is one of the main reasons for track deterioration. Fouling materials come from various sources including ballast breakdown, external materials including coal falling off freight trains, and clay slurry pumped up from subgrade. Ballast fouling will lead to poor drainage in the track and then increase the moisture content of the subgrade posing undrained failure risks. Fouling also reduces the strength and stiffness of the ballast and leads to excess deformation of the track. Highly fouled ballast loses its functions related to drainage, absorbing shocks (impact) and noise levels. Therefore, ballast conditions should be regularly inspected and maintenance should be timely conducted to ensure safe track operations.
