RAILWAY BRIDGE IMPACTS RESULTING FROM FLAT WHEELS AND TRACK IRREGULARITIES

The impact factors in bridge members due to flat wheels and track irregularities were investigated. The maximum wheel flat height was taken as 0.2 in., maximum pier settlement as plus or minus 0.25 in., and maximum camber error as plus or minus 0.5 in.. The track roughness spectra for Class 6 track was used in the analysis, and only selected members of the 175 ft. pinned connection truss bridge were studied. A train of three, 70-ton freight cars with spring constants of 11.2 kip/in. per wheel was used. The train was moving at various speeds and with initial car displacements of 0.25 in. and car rolls of 0.02 rad. Damping of the bridge and vehicles was neglected. The impact factors for the train moving at 50 mph agree fairly well with the current AREA Specification.

• Corporate Authors:

  Association of American Railroads Research Center

  3140 South Federal Street
  Chicago, IL  United States  60616
• Authors:
  • Wiriyachai, A
  • Chu, K H
  • Garg, V K
• Publication Date: 1981-3

Media Info

• Features: Figures; References; Tables;
• Pagination: 43 p.

Subject/Index Terms

• TRT Terms: Bridges; Defects; Impact loads; Operating speed; Railroad tracks; Railroad trains; Speed; Stresses; Structural analysis; Train operations; Train track dynamics; Truss bridges; Vibration; Wheels
• Old TRIS Terms: Bridge stresses; Flat wheels; Impact loading; Track irregularities
• Subject Areas: Bridges and other structures; Railroads; Vehicles and Equipment;

Filing Info

• Accession Number: 00334731
• Record Type: Publication
• Report/Paper Numbers: AAR R-475 Res Rpt.
• Files: TRIS
• Created Date: Jul 9 1981 12:00AM