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Importance of vertical rail track stiffness on dynamic overloading: Limitations of the Eisenmann
formulation

2.3 Stiffness and dynamic overload results

Due to the nonlinear behavior of the material, the loads need to be applied in several stages. In
the first stage, only the weight of the materials is considered until the equilibrium of the stres-
ses is achieved, whereas the load caused by the train is considered in subsequent stages. Becau-
se the displacements of interest correspond to the load from the train, they will be obtained by
the difference between the totals after applying the train load and the values that correspond
to the first stage. According to Committee D-71 of the International Union of Railways Office
for Research and Experiments (Office de Recherches et d’Essais de l’Union Internationale des
Chemins de fer, ORE, Report No. 28, 1983), the load is distributed on the four sleepers adjacent
to the sleeper that is loaded, two on each side. This distribution implies that the real value of
the settlement of the rail head caused at a certain point by the load of the wheel that acts on
it can only be determined by considering the previous loads that affect this point. The load of
at least three consecutive sleepers—the first two sleepers (T5 and T6) previous to the sleeper
that is being analyzed (T7), and the latter—must be considered.
Table 3.
Dynamic coefficient values C for different types of structure strengths of the rail track.
d

DYNAMIC STIFFNESS (tn/mm) DYNAMIC COEFFICIENT
TYPE OF
INFRASTRUCTURE
K (T5) K (T6) K (T7) K (T8) SLEEPER 5 SLEEPER 6 SLEEPER 7 SLEEPER 8
Embankment=QS2 Natural
Ground=QS1 1.019 0.770 0.674 0.622 1.36 1.33 1.32 1.31
Embankment=QS2 Natural 1.572 1.371 1.225 1.161 1.41 1.39 1.38 1.37
Ground=QS2
Embankment=QS2 Natural
Ground=QS3 3.323 3.181 3.128 3.061 1.56 1.55 1.54 1.54
Embankment=QS2 Natural
Ground=ROCA 3.843 3.781 3.758 3.677 1.59 1.59 1.59 1.58
Embankment=QS3 Natural 2.890 2.596 2.469 2.393 1.52 1.50 1.49 1.49
Ground=QS1
Embankment=QS3 Natural
Ground=QS2 5.093 4.931 4.905 4.867 1.67 1.66 1.66 1.65
Embankment=QS3 Natural 7.061 7.061 7.115 7.087 1.77 1.77 1.78 1.78
Ground=QS3
Embankment=QS3 Natural 7.403 7.432 7.471 7.468 1.79 1.79 1.80 1.80
Ground=ROCA
Embankment=MGT Natural
Ground=QS1 6.778 6.778 6.853 6.828 1.76 1.76 1.76 1.76
Embankment=MGT Natural 7.368 7.339 7.397 7.368 1.79 1.79 1.79 1.79
Ground=QS2
Embankment=MGT Natural
Ground=QS3 8.321 8.359 8.434 8.434 1.84 1.84 1.84 1.84
Embankment=MGT Natural
Ground=ROCA 8.780 8.776 8.817 8.830 1.86 1.86 1.86 1.86
Source: Prepared by the authors, 2017

International Congress on High-speed Rail: Technologies and Long Term Impacts - Ciudad Real (Spain) - 25th anniversary Madrid-Sevilla corridor 307