Evaluation of railway trackbed moduli using the rail falling weight test method and its backcalculation model

Abstract

A new falling weight test method based on the direct impact on the rail was studied and a backcalculation model was developed to estimate the moduli of the railway substructure layers. The model is three-dimensional, dynamic, and considers the superstructures. After the preliminary studies on the impact system and measurement setup on a test track, a case study was performed on a railway station track. The data were recorded using a series of linear variable differential transformers, geophones, and accelerometers during the proposed falling weight test on the rail. To establish the soil profile and better understanding of the site, geotechnical and geophysical investigation of the soil was done using in situ and conventional laboratory tests. The studies show that the rail falling weight test is feasible and leads to reasonable results. Verification of the backcalculation model with the ABAQUS finite element simulation and comparison of the backcalculated moduli with the results of site investigations show that the function of the backcalculation model is satisfactory.