ABSTRACT
This chapter presents the influences of confining pressure and frequencies on the degradation of railway ballast. Railway tracks are mainly influenced by the degradation of ballast particles. The degradation of particle is the primary cause of contamination and accounts for up to 40% the fouled material. The main factors that affect ballast degradation can be grouped into three categories: properties related to the characteristics of the parent rock; physical properties related to individual particles; and factors associated with the assembly of particles and loading conditions. A large-scale process simulation testing apparatus (PSTA) was designed and built to study the response of ballast track components under realistic cyclic loading; it was the first of its kind in the world when used in the early 1990s. The influence of train speed on the permanent deformation and degradation of ballast during cyclic loading has been studied using the large-scale cylindrical triaxial apparatus.
