Bridge Tests by Using the Track Loading Vehicle

The Track Loading Vehicle (TLV) was used to conduct a series of bridge tests. The Big Creek Through Truss Bridge on the Norfolk Southern Railroad in Tennessee was used for the tests. The theoretical and experimental axial forces in bridge members were compared. The TLV generated influence lines, impact percentages and resonance curves of member axial forces were determined. The damping ratios in bridge members were also evaluated. The results indicate that the TLV can be used in the study of stresses, impact percentages, mode shapes, natural frequencies and damping in the bridge and its members. An experimental TLV influence line for a selected bridge member can be obtained, leading to an assessment of the actual force distribution among various members. The test findings suggest that a significant difference can exist between the theoretically calculated stresses and those measured during the test - measured stresses are often lower. The TLV impact tests showed that least impact (increase in stress) occurred in end posts and most in the diagonals. The maximum impact percentages in the bridge members were found to be lower than 35 percent. The bridge natural frequencies were found to be 3, 7 and 13 Hertz in the first three modes. It was also found that member vibrations were not affected by the added mass of the TLV consist on the bridge, and thus provided a useful tool in ascertaining the vibrational characteristics of a truss bridge structure using the TLV.

• Record URL:
  https://www.fra.dot.gov/eLib/details/L16776#p1_z50_gD_lRT_y1993
• 
• Corporate Authors:

  Association of American Railroads Technical Center

  3140 South Federal Street
  Chicago, IL  United States  60616

  Federal Railroad Administration

  Office of Research and Development, 1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Singh, Satya P
• Publication Date: 1993-12

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Research Report
• Features: Appendices; Figures; Maps; Photos; References;
• Pagination: 144p

Subject/Index Terms

• TRT Terms: Damping (Physics); Dynamic tests; Natural frequency; Railroad bridges; Static tests; Stresses; Truss bridges; Vibration
• Identifier Terms: Norfolk Southern Railway Company
• Uncontrolled Terms: Track loading vehicles
• Geographic Terms: Tennessee
• Subject Areas: Bridges and other structures; Railroads;

Filing Info

• Accession Number: 01668915
• Record Type: Publication
• Report/Paper Numbers: R-837
• Contract Numbers: DTFR53-86-C-00011
• Files: TRIS, ATRI, USDOT
• Created Date: May 10 2018 5:45PM