An accurate method for fast assessment of under slab mats (USM) performance in ballastless track structures

Zbiciak, Artur; Kraśkiewicz, Cezary; Dudziak, Sławomir; Sabouni-Zawadzka, Anna Al; Pełczyński, Jan

doi:10.1016/j.conbuildmat.2021.123953

Cited by 15 publications

(4 citation statements)

References 24 publications

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“…To simulate the mechanical behavior of the geotextile between the SCC and the base plate, frictional contact was applied to simulate sliding and friction [32]. Considering the elastic buffering effect of the elastic rubber cushion on the convex platform, the contact between SCC and the convex platform was simulated by friction contact in the tangential direction and linear elastic contact in the normal direction [33,34]. Moreover, since this research focused on the interface damage between the track slab and SCC, the tie constraint was adopted to simplify the connection of the base plate and subgrade, which assumed that there was no debonding or slip between the concrete base and subgrade.…”

Section: Fem Of Crts III Slab Trackmentioning

confidence: 99%

Evolution Mechanism of Interlayer Properties of CRTS III Slab Track during Construction

Wang,

Gao,

Wang

et al. 2024

Applied Sciences

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The interlayer properties of the CRTS III slab track during construction directly affect its long-term service condition. This article introduces time-varying coefficients that characterize the early properties of the interface between track slab and SCC to improve the bilinear CZM. Based on this, an interlayer property evolution model of the CRTS III slab track during construction is established. The evolution mechanism of interlayer properties under complex loads and the influence mechanism of key parameters on them are revealed. The results show that after SCC pouring, the interlayer damage at the corner of the slab becomes a sensitive area due to the combined effects of SCC shrinkage and temperature gradients. Interlayer damage initially manifests at the corner of the slab before progressively spreading toward the center of the slab, influencing the composite performance and force transmission characteristics of the track structure. The interlayer bonding property, shrinkage performance of SCC, and construction temperature substantially affect interlayer damage evolution. To reduce the risk of damage, mineral admixtures and expansion agents can be added as additives to improve the bonding property and minimize shrinkage of SCC. Insulation measures should be taken for SCC during low-temperature construction, and SCC pouring construction below 0 °C and above 30 °C should be avoided.

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Section: Fem Of Crts III Slab Trackmentioning

confidence: 99%

Evolution Mechanism of Interlayer Properties of CRTS III Slab Track during Construction

Wang,

Gao,

Wang

et al. 2024

Applied Sciences

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“…In order to be close to the actual application scenario, we used the abnormal data in the early and late stages of the first track defect as the training set, and the corresponding data of the second track defect as the test set. Each measurement area used 60 sets of passing traffic signals to train the HMM; as the normal measurement area encompassed various types of track beds, including shock-absorbing track beds [25,26], vibration-absorbing fasteners, and overlapping optical cable lines, the signals in the abnormal measurement area exhibited similar behaviour. To cover all scenarios, a model had to be constructed for each measurement area.…”

Section: Experimental Data Description and Software Environmentmentioning

confidence: 99%

Detection of Track Bed Defects Based on Fibre Optic Sensor Signals and an Improved Hidden Markov Model

Li,

He,

et al. 2024

Electronics

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Railway track bed defects affect the normal operation of trains and pose great safety risks. In order to detect such issues early, we developed a railway track bed defect detection method which uses optical fibre sensors and an improved HMM (hidden Markov model) to detect the signals collected by a DAS (distributed acoustic sensing) system. First, by analysing the physical process of train operation and determining the number of hidden states, a waveform segmentation method based on average amplitude was used to solve the problem of unequal signal lengths. Second, an adaptive power spectrum energy ratio calculation method was employed to extract track fault features, a set of which was constructed by combining various quantity features. Then, normal and abnormal models were trained according to the sensor measurement area. Finally, the probability of detecting the signal with each model was compared to determine whether the signal was abnormal. Experiments were conducted to compare the applicability of the waveform segmentation method and the feature extraction method. The results show that the HMM based on both waveform segmentation and track bed defect feature sets had the highest recognition rate, the lowest number of false detection areas, and a greater impact on the signal in the early development stage of track bed defects. The proposed method, therefore, has strong recognition ability, which makes it suitable for track bed defect detection.

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“…Liu et al [14] conducted vibration and noise tests on a 30 m U-shaped girder bridge equipped with vibration-damping fasteners and found that the fasteners can effectively reduce the vibration but have little effect on acoustic control. Zbiciak et.al [15,16] carried out tests under slab mats to reduce under-rail vibrations; they found that slab mats can effectively reduce vibrations in the frequency range above 34 Hz, and the insertion loss for the 30 mm thickness of under slab mats is up to 75%. Wettschureck et al [17,18] conducted field tests on the railway line installed under ballast mats.…”

Section: Introductionmentioning

confidence: 99%

Bridge-Borne Noise Induced by High-Speed Freight Electric Multiple Units: Characteristics, Mechanisms and Control Measures

Du,

Wang,

et al. 2024

Applied Sciences

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The high-speed freight electric multiple unit (EMU) is one of the important development directions for railway freight transportation. To investigate the bridge radiation noise induced by the freight EMU, a noise prediction model consisting of the containers–vehicle–track–bridge dynamic model, finite element model, and boundary element model are established and validated. Through simulation, the bridge radiation noise under different train loading conditions is compared, and the noise radiation mechanism is revealed. Moreover, the noise reduction effect of the noise wall is studied, and the influences of noise wall heights and sound absorption materials are investigated. Results indicate that the bridge sound power and the sound pressure levels (SPLs) of near-field points increase slightly with train loads in the frequency range below 20 Hz and above 125 Hz, with a maximum increase of about 6.8 dB. The structure resonance, intense local vibration, and high acoustic radiation efficiency cause strong bridge radiation noise. The noise wall can realize a good overall noise reduction effect in the sound shadow zone; nevertheless, SPLs increased in areas between the bridge and the noise wall. The ground reflection affects the superposition of transmitted, reflected, and diffracted sound waves, which causes nonlinear relationships of noise reduction effects with the noise wall height. From the perspective of human hearing sensitivity, the loudness levels of typical field points increase with the frequency in the range of 20~80 Hz, and SPLs below 25 Hz are less than the threshold of hearing. Setting the noise wall can effectively reduce the loudness levels, and the reduction effect increases with the noise wall height.

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An accurate method for fast assessment of under slab mats (USM) performance in ballastless track structures

Cited by 15 publications

References 24 publications

Evolution Mechanism of Interlayer Properties of CRTS III Slab Track during Construction

Evolution Mechanism of Interlayer Properties of CRTS III Slab Track during Construction

Detection of Track Bed Defects Based on Fibre Optic Sensor Signals and an Improved Hidden Markov Model

Bridge-Borne Noise Induced by High-Speed Freight Electric Multiple Units: Characteristics, Mechanisms and Control Measures

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