Abstract
The structural adequacy challenges of railroad track structures have received considerable attention globally. Track defects and failures due to weak strength and buckling effect account for one-third of all railroad accidents. The current paper provides a comprehensive study of the recent work on the structural adequacy/bearing capacity of rail systems from mechanical engineering perspectives; existing techniques for track stiffness/modulus evaluations, including standstill and continuous methods. Further, this paper demonstrates the current techniques for track stiffness/modulus evaluation. Prevailing track modulus techniques, while accurate but time-taking, effortful, requires a track closure and provides only single-point information. Also, this review provides a suggestion on the non-destructive and non-invasive technologies for example Ground-penetrating radar (GPR) and evaluation of the substructures of tracks as they have great potential for image subsurface features.