The Characteristics of Long-Wave Irregularities in High-Speed Railway Vertical Curves and Method for Mitigation
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View abstract on PubMed
Summary
This summary is machine-generated.S-shaped long-wave irregularities (SLIs) in high-speed rail are caused by design imperfections, not track deformation. Adding parabolic or sinusoidal transition curves effectively mitigates these irregularities and improves ride comfort.
Area Of Science
- Railway Engineering
- Geotechnical Engineering
- Transportation Science
Background
- Track geometry measurements (TGMs) are vital for high-speed railway (HSR) safety and maintenance.
- S-shaped long-wave irregularities (SLIs) are observed at vertical curve transitions.
- Existing methods do not fully address the root cause of SLIs.
Purpose Of The Study
- Analyze the characteristics of SLIs.
- Identify the cause of SLIs in vertical curves.
- Propose a method to mitigate SLIs and improve track quality.
Main Methods
- Analysis of track geometry data from track geometry cars (TGCs).
- Design and simulation of a long-wave filter for inertial measurement systems (IMSs).
- Investigation of the quantitative relationship between SLIs and longitudinal profiles.
- Proposal and simulation of transition curves (TDPTC, FSTC).
Main Results
- SLIs originate from imperfections in the longitudinal profile design, not track deformation.
- Abrupt changes in vehicle acceleration are identified as the cause of measured SLIs.
- Third-degree parabolic transition curves (TDPTCs) and full-wave sinusoidal transition curves (FSTCs) effectively smooth vertical acceleration.
- The proposed transition curves significantly mitigate SLIs.
Conclusions
- SLIs are a result of longitudinal profile design flaws, leading to abrupt acceleration changes.
- Implementing TDPTCs or FSTCs provides a viable solution for eliminating abrupt acceleration changes.
- The proposed transition curves effectively reduce SLIs, enhancing HSR safety and ride quality.
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