A Laboratory Test Method for Measuring Realistic Trackbed Pressures at the Tie/Ballast Interface

This report documents the development of a practical and reliable laboratory method for calibrating pressure cells and quantifying typical railway trackbed pressures at the tie/ballast interface under simulated trackbed conditions. Vertical pressures were applied by a hydraulic compression test machine to prototype sections of the trackbed consisting of a section of rail placed on a tie plate and a section of a wood tie, supported by specially designed frames/boxes containing the ballast and subballast. The granular material pressure cells were recessed within the bottom of the ties, thus suitably positioned for subsequent in-track measurements. Loading magnitudes, applied by the testing machine, and resulting vertical interfacial pressures were similar to those exerted by locomotives and loaded freight cars traveling at typical freight train speeds. Particular attention was given to evaluating the effects of various procedures for positioning the cells within the interface and attaching the cells to the ties. Additional attention was given to optimizing the design of the ballast and subballast containment frames and testing procedures so that the stress dissipation would simulate in-track loadings typically produced by freight trains.

• Record URL:
  http://www.nurailcenter.org/research/final_reports/UIUC/NURail2016-UKY-R12%20Final%20Report-compressed.pdf
• 
• Supplemental Notes:
  • The final report for NURail project: NURail2016-UKY-R12 consists of six distinct documents related to the project titled: “Pressure distributions and magnitudes at the tie/ballast interface.” This document appears on pp 66-86 of the final report. This document was sponsored by the U.S. Department of Transportation, University Transportation Centers Program.
• Corporate Authors:

  University of Kentucky, Lexington

  Department of Civil Engineering
  176 Raymond Building
  Lexington, KY  United States  40506-0281

  National University Rail Center (NURail)

  University of Illinois at Urbana-Champaign
  Department of Civil and Environmental Engineering, 205 N. Mathews Avenue
  Urbana, IL  United States  61801

  Office of the Assistant Secretary for Research and Technology

  University Transportation Centers Program
  Department of Transportation
  Washington, DC  United States  20590
• Authors:
  • Rose, Jerry G
  • Clarke, David B
  • Liu, Qunglie
  • Watts, Travis J
• Publication Date: 2018-1-23

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Photos; References; Tables;
• Pagination: pp 66-86

Subject/Index Terms

• TRT Terms: Ballast (Railroads); Calibration; Compression tests; Freight trains; Laboratory tests; Load cells; Railroad ties; Simulation; Subballast; Test procedures
• Subject Areas: Maintenance and Preservation; Railroads; Vehicles and Equipment;

Filing Info

• Accession Number: 01745092
• Record Type: Publication
• Report/Paper Numbers: NURail 2016-UKY-R12c
• Contract Numbers: DTRT13-G-UTC52
• Files: UTC, TRIS, ATRI, USDOT
• Created Date: Jul 15 2020 9:08AM