Statistical analysis of stability of continuous welded rail with track irregularity

In order to make up the defect that the existing stability design method did not distinguish the level of track regularities, a probabilistic statistical analysis method for the stability of continuous welded rail (CWR) was proposed based on numerical simulation of track irregularities and the finite element method. The proposed analysis method could take into account the randomness of track irregularities and the lateral resistance of ballast bed (LRBB). For railway with different radii, the influences of the randomness of track irregularities and LRBB on the statistical distribution of allowable temperature rise range of rail (ATRR) for CWR were studied. And the results contrast between the proposed method and the existing method was carried out. The results are drawn as follows. When the LRBB is normal, the ATRR considering the randomness of the value of LRBB alone approximately follows the Gumbel distribution. When the randomness of track irregularities is considered solitary, or when the randomness of the value and distribution of LRBB are considered together, or when all of the three factors are considered together, the ATRR follows the normal distribution. The standard value of ATRR defined by a guarantee rate of not less than 95%, and the mean value of ATRR increase as the track regularity is improved. For railway with different radii, the ATRR determined by the existing method of “equal wavelength finite element” is approximately equal to the standard value of ATRR corresponding to the 5th track spectrum for American railway lines, but there are great differences in the corresponding results of alternative track spectrums. Considering the factors of track irregularities and LRBB, the display mapping relationships between the mean value, standard deviation and standard value of ATRR and the curve radius are established. The relations make it possible to distinguish the level of track regularity in the stability analysis of CWR. The research results can provide reference for further optimizing the limit state design method of CWR. © 2024, Central South University Press. All rights reserved.