RAILROAD TRACK ANALYSES AND DETERMINATION OF PARAMETERS.

The standard analysis for crosstie tracks assumes that each rail responds like an elastic beam that is attached to a base of closely spaced linearly elastic springs. However, early field tests revealed that the relation between the vertical rail deflections and the wheel loads is nonlinear. This problem is analyzed by representing this nonlinearity with a bilinear response. This paper presents a systematic method of solution, establishes a method for determining the three rail-support parameters of the bilinear response, establishes the accuracy of the obtained solution by comparing it with the corresponding field test data, and determines under what conditions will the results predicted by the standard linear analysis be on the conservative side. It was found that for the problem under consideration the standard analysis grossly underestimates the maximum force that the rail exerts on the crossties.