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Record W4293764631 · doi:10.1061/9780784484371.003

Review of TCRP Rail Break Gap Formulas

2022· article· en· W4293764631 on OpenAlexaff
Nazmul Hasan

Bibliographic record

VenueInternational Conference on Transportation and Development 2022 · 2022
Typearticle
Languageen
FieldEngineering
TopicRailway Engineering and Dynamics
Canadian institutionsSNC-Lavalin (Canada)
Fundersnot available
KeywordsFastenerTrack (disk drive)Structural engineeringEngineeringMechanical engineering

Abstract

fetched live from OpenAlex

Assessment of a rail break gap is important to ensure safety of rail traffic. An axial rail model available in current textbook yields a single formula in terms of breathing length to compute a rail break gap in a continuously welded rail (CWR) track. Transit Co-operative Research Program (TCRP) suggests three formulas to compute a rail break gap in a CWR track. The longitudinal resistance of a track or rail is a significant input to compute a breathing length which in turn determines a rail break gap. TCRP does not recommend value of longitudinal resistance of a track or rail but implicitly suggests dividing fastener restraint force by fastener spacing to determine longitudinal resistance value in the derivation process of its first and third formula. The theoretical and practical deficiencies of first and third formula are discussed. TCRP second formula, simplified version of the first one, appears to be acceptable provided the longitudinal resistance of a track or rail is not computed by dividing fastener restraint force by fastener spacing. The value of longitudinal resistance obtained by dividing fastener restraint force by fastener spacing is underestimated for a direct fixation track leading to a large rail break gap and is not appropriate for a ballasted track as well; an explanation for underestimation and inappropriateness is given. The track professionals would be benefitted by the clarity given in the paper. A call is made for review of TCRP formulas.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.002
metaresearch head score (Gemma)0.011
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Not applicable · Consensus signal: none
GenreCandidate signal: Review · Consensus signal: Review
Teacher disagreement score0.015
Threshold uncertainty score0.050

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0020.011
Meta-epidemiology (narrow)0.0020.001
Meta-epidemiology (broad)0.0010.002
Bibliometrics0.0070.008
Science and technology studies0.0010.001
Scholarly communication0.0020.004
Open science0.0040.002
Research integrity0.0020.002
Insufficient payload (model declined to judge)0.0150.011

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.024
GPT teacher head0.244
Teacher spread0.220 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designNot applicable
Domainnot available
GenreReview

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations1
Published2022
Admission routes1
Has abstractyes

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