Analysis on dynamic performance of different track transition forms using the discrete element/finite difference hybrid method

Shi, Chen; Zhao, Chunfa; Xu, Zhang; Andersson, Andréas

doi:10.1016/j.compstruc.2019.106187

Cited by 21 publications

(4 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Research works on transition zone problems focused on the vehicle-track dynamics influenced by track geometry irregularity and track stiffness variations [66][67][68][69][70][71]. The distribution of differential settlement in transition zones was investigated using in situ measurements and laboratory model tests [72][73][74][75]. In soft soil area, the bored piles are generally employed for bridge supporting foundation.…”

Section: Differential Settlement Control Technologiesmentioning

confidence: 99%

Review of research on high-speed railway subgrade settlement in soft soil area

2020

View full text Add to dashboard Cite

Construction issues of high-speed rail infrastructures have been increasingly concerned worldwide, of which the subgrade settlement in soft soil area becomes a particularly critical problem. Due to the high compressibility and low permeability of soft soil, the post-construction settlement of the subgrade is extremely difficult to control in these regions, which seriously threatens the operation safety of high-speed trains. In this work, the significant issues of high-speed railway subgrades in soft soil regions are discussed. The theoretical and experimental studies on foundation treatment methods for ballasted and ballastless tracks are reviewed. The settlement evolution and the settlement control effect of different treatment methods are highlighted. Control technologies of subgrade differential settlement are subsequently briefly presented. Settlement calculation algorithms of foundations reinforced by different treatment methods are discussed in detail. The defects of existing prediction methods and the challenges faced in their practical applications are analyzed. Furthermore, the guidance on future improvement in control theories and technologies of subgrade settlement for high-speed railway lines and the corresponding challenges are provided.

show abstract

Section: Differential Settlement Control Technologiesmentioning

confidence: 99%

Review of research on high-speed railway subgrade settlement in soft soil area

2020

View full text Add to dashboard Cite

show abstract

“…Nevertheless, the operational phase often witnesses the emergence of substantial differential settlements between the road and the culvert, resulting in abrupt alterations in vehicle behavior at the junction. This phenomenon aligns with the mechanism underlying the "bridgehead bump" phenomenon, and it has been elucidated that the primary driver behind the observed differential settlement lies in the substantial disparity in stiffness between the subgrade structure and the culvert structure [1,2]. This sudden alteration in stiffness has the potential to induce rapid fluctuations in the dynamic response of traffic loads at the juncture, consequently giving rise to noteworthy differential deformation following prolonged interaction.…”

Section: Introductionmentioning

confidence: 56%

In Situ Investigation of the Dynamic Response and Settlement in the Expressway Culvert–Subgrade Transition Section Using a Vibration Exciter

Lu,

Xu,

Chen

et al. 2023

Applied Sciences

View full text Add to dashboard Cite

During the operational phase of the expressway, a significant challenge arises concerning substantial differential settlement in the transition zone connecting the culvert and the general subgrade, affecting its smoothness. In order to address the issue of abrupt stiffness variations within the transition section and to mitigate the occurrence of differential settlement, a gradient pile–reinforced-concrete slab composite foundation was implemented for the first time within an expressway culvert–subgrade transition section. At the same time, an in situ vibration test was conducted through the SBZ30 vibration exciter to comprehensively understand the vertical dynamic responses in the culvert–subgrade transition section under various axle loads and speed conditions. Furthermore, continuous monitoring was conducted to track the long-term settlement of the roadbed. The findings indicate that the utilization of gradient pile–reinforced-concrete slab composite foundations can significantly mitigate the amplitude of the dynamic response parameters. Moreover, dynamic parameters and attenuation coefficients exhibit a gradual reduction as the depth increases. Dynamic stresses, acceleration, and displacements on the roadbed surface exhibited positive correlations with both the axle weight and vehicle speed. However, at deeper depths, the load weight exerted a more pronounced influence. As the speed rose, acceleration decayed faster, affecting a shallower depth. Conversely, the increased load slowed the acceleration decay. The cumulative deformation of the roadbed and the number of excitations followed exponential function characteristics. Settlement values progressively increased while the settlement rate gradually diminished, eventually reaching a stable state, ultimately stabilizing within 4.7 mm. These research outcomes offer valuable guidance and serve as a reference for the implementation of gradient pile–reinforced-concrete slab composite foundations within the culvert–subgrade transition section.

show abstract

“…For the transition zones, the coupled DEM-FEM models are becoming popular [141]. However, the computation cost remains a big problem, even though in [142] the 2D clusters (Table 1; No. 6) are applied and the subgrade is built with the FEM.…”

Section: Ballast Bed Degradation Mechanismmentioning

confidence: 99%