Estimating Deterioration in the Concrete Tie-Ballast Interface Based on Vertical Tie Deflection Profile: A Numerical Study

Details

• Creators:
  Yu, Hailing
• Corporate Creators:
  John A. Volpe National Transportation Systems Center (U.S.)
• Subject/TRT Terms:
  Ballast Crib Concrete Ties Deflection Tests Failure Finite Element Method Inspection Equipment Prestressed Concrete Ties Railroad Ties Wire
• Publication/ Report Number:
  JRC2016-5783
• Resource Type:
  Research Paper
• Geographical Coverage:
  United States
• Corporate Publisher:
  American Society of Mechanical Engineers
• Abstract:
  In ballasted concrete tie track, the tie-ballast interface can
  
  deteriorate resulting in concrete tie bottom abrasion, ballast
  
  pulverization and/or voids in tie-ballast interfaces. Tie-ballast
  
  voids toward tie ends can lead to unfavorable center binding
  
  support conditions that can result in premature concrete tie
  
  failure and possible train derailment. Direct detection of these
  
  conditions is difficult. There is a strong interest in assessing the
  
  concrete tie-ballast interface conditions indirectly using
  
  measured vertical deflections.
  
  This paper seeks to establish a link between the vertical
  
  deflection profile of a concrete tie top surface and the tie-ballast
  
  interface condition using the finite element analysis (FEA)
  
  method. The concrete tie is modeled as a concrete matrix
  
  embedded with prestressing steel strands or wires. The
  
  configurations of two commonly used concrete ties, one with 8
  
  prestressing strands and the other with 20 prestressing wires, are
  
  employed in this study. All models are three-dimensional and
  
  symmetric about the tie center. A damaged plasticity model that
  
  can predict onset and propagation of tensile cracks is applied to
  
  the concrete material. The steel-concrete interface is
  
  homogenized and represented with a thin layer of cohesive
  
  elements sandwiched between steel and concrete elements.
  
  Strand- or wire-specific elasto-plastic bond models developed at
  
  the Volpe Center are applied to the cohesive elements to account
  
  for the interface bonding mechanisms. FE models are developed
  
  for both original and worn concrete ties, with the latter assuming
  
  hypothetical patterns of reduced cross sections resulting from
  
  abrasive interactions with the ballast. Static analyses of
  
  pretension release in these concrete ties are conducted, and
  
  vertical deflection gradients along tie lengths are calculated and
  
  shown to correspond well with the worn cross sectional patterns
  
  for a given reinforcement type.
  
  
• Format:
  PDF
• Collection(s):
  Volpe Center
• Main Document Checksum:
  urn:sha-512:9646653e6b19bb769dd26fc6972293f20aa35e6b1baca8d49c0cc711fafc73a8259232bc4e2411e1f1da0356fecc1917814e4ba7de6b8a66414f06515f3dc90c
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/12286/dot_12286_DS1.pdf
• File Type:
  [PDF - 2.05 MB ]