Properties of fouled railroad ballast (phase 1).

Details

• Creators:
  Rahman, A.J. ; Parsons, Robert ; Han, Jie
• Corporate Creators:
  Mid-America Transportation Center
• Corporate Contributors:
  United States. Department of Transportation. Research and Innovative Technology Administration ; United States. Department of Transportation. University Transportation Centers (UTC) Program
• Subject/TRT Terms:
  • Ballast (Railroads)
  • Deterioration
  • Pore water pressures
  • Drainage
  • Resistivity method
  • Permeability
  • Ballast (Railroads)--Deterioration
  • Fouling
  • Railroad drainage
  • Permeability
• Publication/ Report Number:
  25-1121-0001-465
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Edition:
  Final report.
• Corporate Publisher:
  Mid-America Transportation Center
• Abstract:
  Ballasted tracks are the most common tracks used in the railroad industry and are designed to provide a stable, safe, and efficient rail ; foundation. A ballasted track consists of superstructure (ties, fasteners, and rails) and substructure (ballast, sub-ballast, and subgrade ; layers). The main functions of ballast are to support the superstructure by distributing the loads from the moving train, and to provide ; lateral resistance to tie movement and drainage. However, ballast deterioration and fouling are major issues in the railroad industry, and ; can be caused by repeated loadings, which lead to crushing ballast that is in contact with ties. Upward migration of subgrade particles ; into the ballast layer can increase fouling in the ballast and decrease drainage through the ballast layer. There is a need for methods to ; easily and inexpensively identify areas that have fouled ballast. The objective of this preliminary study was to evaluate the potential for ; estimating the level of fouling in a ballast layer by soil resistivity and permeability tests to be followed by a second study. A test box was ; designed and fabricated at the lab at the University of Kansas to perform the constant head permeability test and soil resistivity tests. ; Constant head tests were conducted to determine the coefficient of permeability of fouled ballast for different fouling percentages. Soil ; resistivity tests were also conducted using the Wenner method (4 point method) to determine the resistivity of ballast for different ; percentages of fouling. The tests showed a relationship between the percentage of fouling and ballast resistivity. The resistance of the ; ballast layer decreased as the percentage of fouling increased due to the presence of water. Fouled material retained water and filled the ; voids between the ballast particles, and therefore decreased resistivity in the ballast layer. The permeability (hydraulic conductivity) also ; decreased as the percentage of fouling increased due to the presence of fine particles between the ballast particles; therefore, ; permeability and resistivity were also correlated
  More +
• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/25427/dot_25427_DS1.pdf
• File Type:
  [PDF - 3.21 MB]
• Collection(s):
  University Transportation Centers ; US Transportation Collection
• Main Document Checksum:
  urn:sha-512:e4491b4d4c6ddf739162be55a0c78c923b2e256bfae3ba843cb68f3237945dd37e2faacda952d6082fe62777988cc63075db7b810b56bd91fa542450e009b2eb