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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Relationship of Inspection Methods to Ballast Degradation Models: Phase II

Document Series:
Technical Reports
Author:
  • Stephen Wilk, Dingqing Li, Dante DeVencenty
Report Number
DOT/FRA/ORD-24/26
Office
RDI-21
Subject:
ResearchTrack
Keywords:
Ballast, settlement, mud pumping, fouling index, forecasting, track inspection, track modulus, track, Railway Track Lifecycle Model, RTLM

This report is a follow on of the first phase of a Federal Railroad Administration (FRA)-sponsored project to evaluate lateral ballast behavior and how mechanics-based track geometry deterioration models forecast field behavior. In Phase II of the project, Transportation Technology Center, Inc. modified the Railway Track Lifecycle Model (RTLM) by adding tamp lift height and a site-specific factor and split the model between a logarithmic settlement and a linear surface profile model. The research team also compared forecasting model projections against multiple field measurement locations at the Transportation Technology Center (TTC). The ballast settlement mechanism at most locations was ballast re-compaction and the RTLM captured the settlement behavior if only the tamp lift height parameter was used. If the settlement mechanism was degraded ballast, the logarithmic settlement curve did not capture abrupt changes in settlement rate from wetting and drying so more linear models, such as the surface profile model, should be used.


Last updated: Monday, August 5, 2024