Technical Reports

Evaluation of Improved Track Structural Components Under Sub-Arctic Conditions

  • 01
  • Jan
  • 1979
AUTHOR: John W. Weber
SUBJECT: Evaluation, Technology Transfer
KEYWORDS: Adjustable Rail Fasteners, Concrete Ties, Stabilized Ballast, Sub-arctic Conditions
ABSTRACT: One area of concern to railroads in the northern third of the United States is the effect of frost heave and subsidence on track geometry. The purpose of this study was to evaluate two methods of improving track geometry and reducing maintenance in sub-arctic environments. Test track sections were installed in frost heave areas of the Alaska Railroad. One installation was designed to evaluate concrete ties with adjustable fasteners. The other installation was designed to evaluate the effect of including an elastic polymer stabilizer in the ballast. The concrete tie adjustable fastener section performed satisfactorily. Ties withstood bending stresses induced by the unfavorable frost heaving support conditions. The fasteners provided an acceptable means of adjusting track during frost heave. Stabilized ballast effectively reduced track subsidence due to weak foundation support. However, other problems such as hardening of the binding material and migration of the un-stabilized ballast layer, made the particular system used unacceptable at this time.