Laboratory Tests and Analyses of the Level of Vibration Suppression of Prototype under Ballast Mats (UBM) in the Ballasted Track Systems

Abstract

The present paper is aimed at the analysis of under ballast mats (UBM) which are used in ballasted track structures as vibration isolators and to protect the ballast layer against fast degradation. The mats were tested in the laboratory and afterwards a novel 4-DoF mechanical model of the track structure with UBM was developed. The novelty of this study consists in the comparison of two testing procedures: a procedure based on the popular German standard DIN 45673-5 and a new European standard EN 17282, released in October 2020. Major discrepancies were demonstrated in the determined values of the static and dynamic characteristics using both approaches—especially in reference to the mats with higher stiffness.

Under ballast mat – A review of recent developments, limitations, and future prospects

“…3,70 Similar results were shown in Kraśkiewicz, Zbiciak. 71 Significant differences in the values of static and dynamic characteristics were seen (from over 30% up to ∼75%) in medium, stiff, and very stiff types of mats among SBR and mineral wool UBMs; however, these discrepancies were ∼10% up to ∼30% for soft mats and 0%–∼20% for very soft mats. 71 In addition, it is clear that the stiffness of rubber UBM changes noticeably with the change of loading level.…”

“…71 Significant differences in the values of static and dynamic characteristics were seen (from over 30% up to ∼75%) in medium, stiff, and very stiff types of mats among SBR and mineral wool UBMs; however, these discrepancies were ∼10% up to ∼30% for soft mats and 0%–∼20% for very soft mats. 71 In addition, it is clear that the stiffness of rubber UBM changes noticeably with the change of loading level. 26 By comparing two kinds of soft and stiff UBMs made of recycled tires, it was proved that generally, they reduce the bearing capacity of the system, which is highlighted in a softer mat.…”

Analysis of the Influence of Fatigue Strength of Prototype Under Ballast Mats (UBMs) on the Effectiveness of Protection against Vibration Caused by Railway Traffic

“…Parameters of the FZ model that were obtained in this analysis were used in the 4DoF model, which describes the behavior of the ballasted track structure. The original 4DoF model was presented in the previously published works of the authors [ 19 ]. Using this model, diagrams of transmissibility and insertion loss (IL) function were prepared.…”

Vibration mitigation design and effect prediction of ballast turnout in metro depot

“…In view of the shortcomings of existing vibration mitigation methods, most metro depots use ballast bed. The under ballast mats (UBM) is commonly used in ballast bed vibration damping [3,4] . But large number of engineering practices have proved that single vibration mitigation method is difficult to meet the vibration mitigation need of 10 dB in metro depot.…”