Analysis of track modulus estimation models using ground penetrating radar (GPR) data

摘要

Railroad track modulus is an important parameter that provides a measure of the vertical stiffness of the rail foundation . It characterises the structural strength of the track, and includes the effects of the fasteners, the ties, and the substructure. Although track modulus is considered important for track performance, it is seldom measured, and its values are usually only roughly estimated over track sections based upon knowledge of the track geometry and aging. In general, higher track modulus represents better track performance. Track modulus values less than I3.7 MPa (2,000 lb/in/in) indicate poor performance, values between 13.7 MPa (2,000 lb/in/in) and 27.5 MPa (4,000 lb/in/in) indicate average performance, and values higher than 27.5 MPa (4,000 lb/in/in) indicate good performance. However, very high track modulus values, typically greater than 137 MPa (20,000 lb/in/in), can cause component failure including ballast degradation or tie cracking due to the severe dynamic loads encountered.