Railway Track Support
being defined as the foundation of the track that underlies the track
superstructure of ties, fasteners and rails.
Track Support components are generally taken to include the underlying layers
of ballast, subballast and subgrade (a.k.a., formation, roadbed), as well as
the track’s drainage condition. The
condition and performance of the Track Support profoundly affects the track
structure and the track’s operational reliability and ride quality. The quality of Track Support is defined by
the following attributes of the Track Support components:
layer thickness and configuration,
(material type) and moisture content, and
stiffness and deformability.
technologies have been employed to quantify these attributes, including ground
penetrating radar, track stiffness measurements, track geometry analysis, lidar
scanning, high-resolution imagery, and instrumentation (in-situ and wayside).
Understand the performance of track
support and stiffness under different environmental and operational conditions
(e.g., heavy axle load, high speed) in order to evaluate and minimize operational
risk, and to determine appropriate maintenance to provide optimum track
reliability and economy. Develop ways to
measure and monitor the condition and performance of Track Support in order to quantify
safety risk and to forecast future performance quality.
Better understanding and improved
monitoring of Track Support will lead to: overall smoother and more reliable track
for a given level-of-service, increased track reliability, reduced rate of
track deterioration, and reduced maintenance and capital costs.
TTCI and some railroad companies are performing large-scale laboratory and
revenue-service testing of Track Support components. Private companies, including railroads,
contractors and engineering firms, as well as universities are developing
methods to reliably and efficiently measure Track Support condition and
performance. There are also ongoing
research efforts utilizing computer modeling, including the use of artificial
computational analytics, laboratory testing, field testing and revenue-service
modeling, laboratory testing and field monitoring, primarily by universities
and private companies, with close partnership with railroad companies.
The effects of the condition and performance of Track Support effects on the overall track reliability and safety are the least understood aspects of railway track health.
|Sponsoring Committee:||AR050, Railroad Infrastructure Design and Maintenance
|Research Period:||24 - 36 months|
|RNS Developer:||James Hyslip, Loram Technologies, Inc|
|Index Terms:||Subgrade (Pavements), Subgrade materials, Ballast (Railroads), Railroad tracks, |