Attenuation of Dynamic Response of Special Track Work Foundations Subjected to Impact Loading

This report deals with damage to special track work due to high impact loads and the beneficial effect of increasing damping in these foundations. Additional damping attenuates the high magnitude and high frequency of impact generated transient vehicle-track vibrations. This report covers the first phase of means, manners, and options for analyzing and enhancing the damping at the special track work locations, especially the crossing diamond foundations. A conventional wood-tie ballasted track at the Transportation Technology Center's (TTC’s) Facility for Accelerated Service Testing had a damping value of about 56 lbs/in/sec/tie/rail. A conventional concrete-tie ballasted track on the Railroad Test Track (RTT), on the other hand, had a damping value of about 164 lbs/in/sec/tie/rail. The measured values were very low compared to the value of the optimal damping of about 300 lbs/in/sec/tie/rail determined in a previous study conducted by Transportation Technology Center, Inc. (TTCI). Since the traditional crossing diamond foundation is very similar to a conventional open track foundation, the damping in existing crossing diamond foundations cannot be expected to be more than the ballasted track on the RTT; i.e., 164 lbs/in/sec/tie/rail. The damping of crossing diamond foundations therefore needs to be increased. The measured damping values at other modified track beds on the RTT consisting of rolled ballast mat and under-tie pads were found to be respectively 319 and 237 lbs/in/sec/tie/rail, and appear to meet the optimal damping provision criterion. Similar modifications then could be used to increase damping in crossing diamond foundations. This work was conducted under Task Order 139 of the Federal Railroad Administration's (FRA’s) Research and Development Plan. During Phase 2, and in concert with a companion Association of American Railroads (AAR) program, results of laboratory tests on various damping pads will be analyzed to produce rank-attenuation relationships. Pads will be tested in heavy axle load environment to determine the deterioration of the dynamic performance and to gage their durability.

• Record URL:
  https://www.fra.dot.gov/eLib/details/L18223#p1_z50_gD_lRT_y2003
• 
• Corporate Authors:

  Transportation Technology Center, Incorporated

  55500 DOT Road, P.O. Box 11130
  Pueblo, CO  United States  81001

  Federal Railroad Administration

  Office of Research and Development, 1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Singh, Satya P
  • Davis, David D
  • Guillen, Don
  • Williams, David
• Publication Date: 2003-5

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Draft Report
• Features: Bibliography; Figures; Photos; References; Tables;
• Pagination: 79p

Subject/Index Terms

• TRT Terms: Concrete ties; Damping (Physics); Foundations; Impact loads; Railroad tracks; Wood ties
• Uncontrolled Terms: Ballasted track; Railroad crossing diamonds
• Subject Areas: Design; Railroads;

Filing Info

• Accession Number: 01682583
• Record Type: Publication
• Contract Numbers: DTFR53-93-C-00001, Task Order 139
• Files: TRIS, ATRI, USDOT
• Created Date: Oct 2 2018 4:56PM