Keywords: subgrade evaluation, railway track monitoring, track stiffness variation, singular value decomposition, instrumented wheelset, beam on elastic foundation.

This paper intends to propose a method for indirect evaluation of railway track substructure using the response measurements of the vehicle. Wheel/rail forces and accelerations are measured by instrumented wheelsets (IWS) and accelerometers, respectively. The IWS system is mounted on a freight railcar and collected data over a short line railroad over Canadian shield with large variation in track stiffness. The relative stiffness of the track could be calculated by the ratio of the magnitude of cyclic load and cyclic displacement. Cycle displacements can be interpreted through the integration of the accelerometer data at the most contributing frequency within both loads and accelerations. An algorithm is proposed to detect the most relevant frequency between load and acceleration and calculate the load/displacement ratio accordingly. To verify the proposed method a numerical simulation is developed in a finite element (FEM) software. Using the validated proposed method, the stiffness variation is estimated on a section consisting of an embankment with lateral supports and the grade crossing. The results confirmed the developed methodology could estimate the stiffness variations and detect track features such as the lateral support of the embankment and the grade crossing as well as soft section that may attribute to some poor subgrade conditions.

download the full-text of this paper (PDF, 889 Kb)

go to the previous paper
go to the next paper
return to the table of contents
return to the volume description