Implementation of spectral analysis of surface waves approach for characterization of railway track substructures

Monitoring and identifying the changes in mechanical properties of the railway track due to climatic fluctuation and operation are crucial. Few systematic methods exist for measuring the mechanical properties of the ballast and foundation layers of a railway track. The Spectral Analysis of Surface Wave (SASW) approach, a nondestructive seismic testing method to measure mechanical properties, has been implemented to evaluate the subsurface conditions of pavements. Due to its straightforward method of data analyses, the possibility of automation and the similarities in layering mechanism and stress distributions in the railway tracks and the pavements, the SASW approach can be employed for rapid assessment of the subsurface conditions of the railway tracks. However, the application of the SASW approach to railway tracks is challenging due to the presence of ties and rails over the tracks and the large variations in characteristics of the ballast and subgrade. This study paper presents the means of studying the complication related to the implementation of the SASW for railway tracks and a suggested alternative in implementing the approach in an optimal manner.