Evaluation of Countermeasures against Differential Settlement at Track Transitions

Namura, Akira; Suzuki, Tsuyoshi

doi:10.2219/rtriqr.48.176

Cited by 39 publications

(23 citation statements)

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“…Auersch (2006) reported that vibrations due to wheel passage were not observed at frequencies over 50 Hz; any vibrations observed at frequencies between 50 Hz and 125 Hz could be related to wheel and rail anomalies. After optical measurement of railway track displacements under a train moving at 220 km/h, Namura and Suzuki (2007) stated that unsupported sleeper information could be discovered using train axle acceleration and that they corresponded to frequencies between 10 Hz to 20 Hz. Priest et al (2010) observed that dominant ground velocities obtained from geophone measurements under the passage of a coal train moving at 50 km/h corresponded to frequencies around 1, 2, and 6 Hz, and concluded that the frequencies correspond to axle spacings and distance between consecutive bogies.…”

Section: Figure 1: Example Representation Of Ballast Transient Deformmentioning

confidence: 99%

Understanding track substructure behavior: Field instrumentation data analysis and development of numerical models

Boler

Mishra

Hou

et al. 2018

Transportation Geotechnics

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Numerous studies have targeted using numerical modeling, field instrumentation, or combinations of both to gain insight into track substructure behavior under loading. In-depth understanding of track substructure behavior serving both passenger and freight trains is critical to developing suitable design and maintenance/rehabilitation methods to ensure adequate performance under loading. This manuscript presents findings from a recently completed study involving advanced instrumentation and numerical modeling to investigate track substructure-related issues at several problematic railroad bridge approaches in the United States. Multi-Depth Deflectometers (MDDs) were installed to measure transient as well as plastic deformations experienced by track substructure layers under loading. Strain gauges were installed on the rail web to measure the vertical wheel loads applied during train passage. Data from the field instrumentation was used to make inferences regarding the relative contributions of different substructure layers towards the differential movement problem. A 3-D Finite Element (FE) model was developed to further understand the behavior of the instrumented locations, and was calibrated using the field instrumentation data. An elastic layered track analysis program, GEOTRACK, was first used to iteratively backcalculate individual track substructure layer moduli from the field measurements; these backcalculated modulus values were subsequently used in the FE model to predict track response under transient loading conditions. Modulus values estimated for the ballast layer were found to be significantly affected by the presence of gaps at the tie-ballast interface at track transitions. Once validated, the model was further modified to match transient displacement results acquired in the field using a quasi-static moving load approach. Good agreement was found between the model predictions and field instrumentation results. Development of advanced numerical models augmented by field instrumentation data can facilitate the design and maintenance of well-performing track structures.

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Section: Figure 1: Example Representation Of Ballast Transient Deformmentioning

confidence: 99%

Understanding track substructure behavior: Field instrumentation data analysis and development of numerical models

Boler

Mishra

Hou

et al. 2018

Transportation Geotechnics

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“…5,[21][22][23] This philosophy attempts to minimize the differential transient displacements between the transition zone and bridge. These fixes can be successful but are difficult to implement as the bridge stiffness often remains significantly greater than the approach even after implementation 4,23 and once the approach substructure begins to permanently displace, the differential transient and permanent displacements between the approach and bridge will restart the deterioration process.…”

Section: Potential Designs and Remedial Actionmentioning

confidence: 99%

“…This likely involves using multiple design features some of which are described in the literature. [4][5][6][20][21][22][23] For remediation of track geometry, tamping is a commonly used technique that involves raising the ballast; this loosens the ballast underlying the tie. The first train pass after tamping compacts the loosened ballast and creates a tie-ballast gap.…”

Section: Potential Designs and Remedial Actionmentioning

confidence: 99%

Root cause of differential movement at bridge transition zones

Stark

Wilk

2015

Proceedings of the Institution of Mechanical Engineers, Part F:

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The results of a Federal Railroad Administration research project into the factors that contribute to differential displacements at railroad track transitions are presented in this paper. Data from instrumented high-speed passenger (Amtrak) sites suggest that poorly supported ties increase the loads applied on the underlying ballast and can accelerate differential displacements. Poorly supported ties amplify the tie-ballast interaction, which eventually results in large permanent vertical displacements at those locations. This paper presents the location and depth at which permanent vertical displacements are occurring, the ''root cause'' of these permanent differential vertical displacements, and design and remedial measures that focus on reducing poorly supported ties in transition zones.

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“…As a result, the wheel-rail interaction forces in transition zones are significantly amplified [ 6 , 8 , 40 , 41 , 42 , 43 , 44 ]. The analytical results in [ 40 ] showed that the wheel-rail interaction forces in the transition zone between the ballast track and slab track were increased up to 54% due to the differential settlement. Similarly, the increase of the wheel-rail interaction forces in the transition between the embankment and the bridge was up to 85% by the differential settlement [ 41 ].…”

Section: Settlement Mechanism In Transition Zonesmentioning

confidence: 99%

Structural Health Monitoring of Railway Transition Zones Using Satellite Radar Data

Wang

Chang

Markine

2018

Sensors

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Transition zones in railway tracks are locations with considerable changes in the rail-supporting structure. Typically, they are located near engineering structures, such as bridges, culverts and tunnels. In such locations, severe differential settlements often occur due to the different material properties and structure behavior. Without timely maintenance, the differential settlement may lead to the damage of track components and loss of passenger’s comfort. To ensure the safety of railway operations and reduce the maintenance costs, it is necessary to consecutively monitor the structural health condition of the transition zones in an economical manner and detect the changes at an early stage. However, using the current in situ monitoring of transition zones is hard to achieve this goal, because most in situ techniques (e.g., track-measuring coaches) are labor-consuming and usually not frequently performed (approximately twice a year in the Netherlands). To tackle the limitations of the in situ techniques, a Satellite Synthetic Aperture Radar (InSAR) system is presented in this paper, which provides a potential solution for a consecutive structural health monitoring of transition zones with bi-/tri-weekly data update and mm-level precision. To demonstrate the feasibility of the InSAR system for monitoring transition zones, a transition zone is tested. The results show that the differential settlement in the transition zone and the settlement rate can be observed and detected by the InSAR measurements. Moreover, the InSAR results are cross-validated against measurements obtained using a measuring coach and a Digital Image Correlation (DIC) device. The results of the three measuring techniques show a good correlation, which proves the applicability of InSAR for the structural health monitoring of transition zones in railway track.

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Evaluation of Countermeasures against Differential Settlement at Track Transitions

Cited by 39 publications

References 0 publications

Understanding track substructure behavior: Field instrumentation data analysis and development of numerical models

Understanding track substructure behavior: Field instrumentation data analysis and development of numerical models

Root cause of differential movement at bridge transition zones

Structural Health Monitoring of Railway Transition Zones Using Satellite Radar Data

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