Phase 2 (2019-2024)
OVERVIEW OF THE PROGRAM
Theme 1: Assessing and improving track performance and reliability
Phase I completed extensive trials (over 12,000 km of measurements) with a commercial vertical track displacement (VTD) measurement system, and developed a new methodology to remove the influence of track conditions so that the subgrade stiffness can be mapped. The results showed the underlying causes of track geometry issues, and where maintenance is incapable of keeping up with degradation, even if maintenance has been recently completed. Phase II expands upon this past work by completing the development of the analysis of VTD measurements.
THEME 2: Assessing ballast quality and degradation
During the testing of the VTD measurement system on CN track, the National Research Council of Canada (NRC) installed an instrumented wheelset (IWS) system on the same rail car. The dataset was collected concurrently with VTD measurements, providing a remarkable opportunity to evaluate the magnitude of dynamic service loads and the impact they have on the reliability of track structures. An analysis of the IWS datasets will determine the relationships between track conditions (roughness, joints, modulus, and change in modulus), train speed, and the loads applied to the infrastructure.
Theme 3: Establishing a quantitative risk management process
Phase I definitively demonstrated the relationship between poor ballast conditions and poor track performance with the use of ground penetrating radar (GPR). The results show that the renewal of ballast through undercutting has long-term improvements in track performance. CN will be implementing the use of GPR to assess ballast and guide undercutting over the next two years. CaRRL will work with CN to review previous findings with before-and-after GPR measurements of track that has undergone renewal. CaRRL will also work with industry partners to develop GPR datasets from the use of higher frequency (>1 GHz) antennas to evaluate the size of pore space within the granular material. The results will directly inform the use of GPR for analyzing the extent and degree of ballast fouling and the effectiveness of current maintenance practices.