The Railway Track and Its Long Term Behaviour

Designers are increasingly involved in designing alternative futures for their cities, together with or self-organized by citizens. This article discusses the fact that (groups of) citizens often lack the support or negotiation power to engage in or sustain parts of these complex design processes. Therefore the “capabilities” of these citizens to collectively visualize, reflect, and act in these processes need to be strengthened. We discuss our design process of “democratic dialogues” in Traces of Coal—a project that researches and designs together with the citizens an alternative spatial future for a partially obsolete railway track in the Belgian city of Genk. This process is framed in a Participatory Design approach and, more specifically, in what is called “infrastructuring,” or the process of developing strategies for the long-term involvement of participants in the design of spaces, objects, or systems. Based on this process, we developed a typology of how the three clusters of capabilities (i.e., visualize, reflect, and act) are supported through democratic dialogues in PD processes, linking them to the roles of the designer, activities, and used tools.

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Railway Track Asset Management, from long-term vision to completion

IABSE Symposium, Guimarães 2019: Towards a Resilient Built Environment Risk and Asset Management ◽

10.2749/guimaraes.2019.1322 ◽

2019 ◽

Author(s):

Andreia Grossinho

Keyword(s):

Asset Management ◽

Railway Track

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Effect of Long-Term Bridge Deformations on Safe Operation of High-Speed Railway and Vibration of Vehicle–Bridge Coupled System

International Journal of Structural Stability and Dynamics ◽

10.1142/s0219455419501116 ◽

2019 ◽

Vol 19 (09) ◽

pp. 1950111 ◽

Cited By ~ 13

Author(s):

Hongye Gou ◽

Longcheng Yang ◽

Zhixiang Mo ◽

Wei Guo ◽

Xiaoyu Shi ◽

...

Keyword(s):

High Speed ◽

Measurement Data ◽

Coupled System ◽

Bridge Pier ◽

Railway Track ◽

Vertical Acceleration ◽

High Speed Train ◽

High Speed Trains ◽

Track Deformation

Operation safety of high-speed trains is dependent on their vibration characteristics, which vary with bridge deformation. This paper studies the influence of bridge pier settlement and girder creep camber, which are two typical types of long-term bridge deformation, on the vibration of high-speed trains. To this end, an analytical approach is presented to link the bridge deformation with railway track deformation; the track deformation is used to analyze the vibration of the CRH2 high-speed train in China. The vibration analysis results are validated using the in-situ measurement data. The present study shows that bridge pier settlement greatly affects the vertical acceleration, derailment coefficient and wheel unloading rate of the high-speed train; incorporating bridge girder camber aggravates the vibration of the train–bridge system. The threshold of bridge pier settlement is suggested to be 11.1[Formula: see text]mm for trains moving at 350[Formula: see text]km/h with regard to the code-specified vibration limit. This study has significant implications for the design and operation of high-speed railways.

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Full-scale multi-functional test platform for investigating mechanical performance of track–subgrade systems of high-speed railways

Railway Engineering Science ◽

10.1007/s40534-020-00221-y ◽

2020 ◽

Vol 28 (3) ◽

pp. 213-231

Author(s):

Wanming Zhai ◽

Kaiyun Wang ◽

Zhaowei Chen ◽

Shengyang Zhu ◽

Chengbiao Cai ◽

...

Keyword(s):

High Speed ◽

Mechanical Performance ◽

Full Scale ◽

Functional Test ◽

Railway Track ◽

High Speed Railway ◽

Ballastless Track ◽

Railway Infrastructure ◽

Test Platform

Abstract Motivated by the huge practical engineering demand for the fundamental understanding of mechanical characteristics of high-speed railway infrastructure, a full-scale multi-functional test platform for high-speed railway track–subgrade system is developed in this paper, and its main functions for investigating the mechanical performance of track–subgrade systems are elaborated with three typical experimental examples. Comprising the full-scale subgrade structure and all the five types of track structures adopted in Chinese high-speed railways, namely the CRTS I, the CRTS II and the CRTS III ballastless tracks, the double-block ballastless track and the ballasted track, the test platform is established strictly according to the construction standard of Chinese high-speed railways. Three kinds of effective loading methods are employed, including the real bogie loading, multi-point loading and the impact loading. Various types of sensors are adopted in different components of the five types of track–subgrade systems to measure the displacement, acceleration, pressure, structural strain and deformation, etc. Utilizing this test platform, both dynamic characteristics and long-term performance evolution of high-speed railway track–subgrade systems can be investigated, being able to satisfy the actual demand for large-scale operation of Chinese high-speed railways. As examples, three typical experimental studies are presented to elucidate the comprehensive functionalities of the full-scale multi-functional test platform for exploring the dynamic performance and its long-term evolution of ballastless track systems and for studying the long-term accumulative settlement of the ballasted track–subgrade system in high-speed railways. Some interesting phenomena and meaningful results are captured by the developed test platform, which provide a useful guidance for the scientific operation and maintenance of high-speed railway infrastructure.

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Numerical analysis of geogrid contribution to railway track reinforcement

MATEC Web of Conferences ◽

10.1051/matecconf/201821112006 ◽

2018 ◽

Vol 211 ◽

pp. 12006

Author(s):

António Lanca ◽

Zuzana Dimitrovová ◽

Madalena Barroso ◽

Simona Fontul

Keyword(s):

Added Value ◽

Railway Track ◽

Railway Network ◽

Vertical Displacements ◽

Downward Propagation ◽

Long Term Performance ◽

Term Performance ◽

Lateral Deformations

In this work, influence of geogrids on overall stabilization of railway tracks is studied numerically. It is expected that by geogrids implementation significant reduction in the downward propagation of stresses will be obtained, which consequently should assure more resilient long-term performance. In this first approach, however, only added value to the confinement level of the ballast layer is analysed, by evaluation of lateral deformations. A case study is related to a part of the Portuguese railway network. The track and the passing vehicle are modelled in commercial explicit dynamics software LS-DYNA. Firstly, the model is validated by comparison with experimental data. Then a fictitious scenario of the same track with a deteriorated region which is further rehabilitated by the geogrid placement is analysed. Different situations are compared in terms of lateral and vertical displacements at several levels, but for simplicity only rail deflections are shown here.

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Railway track design & degradation

MATEC Web of Conferences ◽

10.1051/matecconf/201821111006 ◽

2018 ◽

Vol 211 ◽

pp. 11006

Author(s):

Mehran Sadri ◽

Tao Lu ◽

Arjen Zoeteman ◽

Michaël Steenbergen

Keyword(s):

Degradation Rate ◽

Early Stage ◽

Mechanical Energy ◽

Measurement Data ◽

Empirical Models ◽

Railway Track ◽

Structural Performance ◽

Design Parameters ◽

Railway Tracks

The long-term behaviour of railway track has attracted increasing attention in recent years. Improvements in long-term structural performance reduce demands for maintenance and increase the continuous availability of railway lines. The focus of this paper is on the prediction of the sensitivity of a track design to long-term deterioration in terms of track geometry. According to the state of the art literature, degradation is often investigated using empirical models based on field measurement data. Although a rough maintenance forecast may be made employing empirical models, the predictions are not generic, and the physical processes which govern track degradation under train operation remain unclear. The first aim of this study is to present a mathematical model to elucidate the underlying physics of long-term degradation of railway tracks. The model consists of an infinitely long beam which is periodically supported by equidistantly discrete sleepers and a moving unsprung mass which represents a travelling train. The mechanical energy dissipated in the substructure is proposed to serve as a measure of the track degradation rate. Secondly, parametric studies on energy dissipation are conducted to identify effects of various track design parameters on the susceptibility of the track to degradation, as well as the effect of the train speed. It has been shown that the track/subgrade stiffness is the most influential parameter on degradation whereas other system parameters do influence the degradation rate but at lower magnitudes. The conclusions can be used to optimise the track design in the early stage for better long-term structural performance of railway tracks.

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Influence of Construction of Railway Superstructure on Railway Quality

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.617.54 ◽

2014 ◽

Vol 617 ◽

pp. 54-59

Author(s):

Libor Ižvolt ◽

Jana Ižvoltová ◽

Janka Šestáková

Keyword(s):

High Speed ◽

Railway Track ◽

Track Geometry ◽

Railway Tracks ◽

Rail Vehicles ◽

Operational Load ◽

Safety And Reliability ◽

Maintenance Work ◽

The Cost

The operation of railway tracks is historically confirmed that the classic structure of the railway superstructure is capable to ensure operational capability of standard railway tracks for a relatively long period of time (railways tracks to speed of 160 km.h-1). Such a railway track and its track is considered the railway track with a classic structure of the railway superstructure, where track removal is stored in the ballast. In the case of high operating and axle load, increasing track speed and requirements for safety of operation, which are associated with high requirements on the track geometry, it appears that such structure has its operational (in terms of guaranteeing the long-term safety and reliability of the railway track) and economic (in terms of the cost of maintenance of railway track) limits. "Floating" placement of the track removal during each passage of a rail vehicle, or train leads to the growth of dynamic horizontal and vertical forces that cause gradual degradation of track geometry, what subsequently leads to restless journey of moving rail vehicles. Elimination of imperfections in track geometry - the quality of the railway track - forces the operators to remove such imperfections of railway track in time and financially consuming maintenance work in certain periods. However, it is sufficient if only the weakest element of classic railway superstructure is replaced in the railway, and it is the track ballast using other more appropriate component representing no elastic and plastic behaviour. The structure is such replacement, in which the track removal is concreted (monolithic structure) or stored on a concrete or asphalt bearing layer (layered structure), namely structural design, which is referred to as unconventional railway superstructure. The structure of railway superstructure is characterized by cross sleepers used in a modified shape or they are not part of it at all. Currently, thus conceived railway track is referred to as a slab track (hereinafter referred to as the "ST"), which requires flexibility of the railway superstructure for the system of the wheel/rail secured using elastic elements disposed between the rail and the sleeper and/or under the sleeper. In general, the structure of ST has been currently applied mainly to high-speed track and the tracks that have high operational load, where the cost of maintaining the track with the classic structure of the railway superstructure strongly grows. At the same time, however, this structure also promotes in the upgraded sections of the standard tracks (track speed to 160 km.h-1), especially in track sections conducted in tunnels, as there are located the required properties of the ballast that do not demonstrate subsidence. The subgrade without a drop also offers for application of the ST structure bridges, and therefore, the application of this structure is also possible in these track sections.

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Quantification of the Mechanized Ballast Cleaning Process Efficiency Using GPR Technology

Remote Sensing ◽

10.3390/rs13081510 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1510

Author(s):

Anna Borkovcová ◽

Vladislav Borecký ◽

Salih Serkan Artagan ◽

Filip Ševčík

Keyword(s):

Time Domain Analysis ◽

Process Efficiency ◽

Railway Track ◽

Relative Dielectric Permittivity ◽

Cleaning Process ◽

Railway Ballast ◽

Railway Infrastructure ◽

Cleaning Intervention ◽

Ground Penetrating

Ground Penetrating Radar (GPR) has been used recently for diagnostics of the railway infrastructure, particularly the ballast layer. To overcome ballast fouling, mechanized ballast cleaning process, which increases track occupancy time and cost, is usually used. Hence it is of crucial significance to identify at which stage of track ballast life cycle, and level of fouling, ballast cleaning should be initiated. In the present study, a series of in situ GPR surveys on selected railway track sections in Czechia was performed to obtain railway granite ballast relative dielectric permittivity (RDP) values in several phases of railway track lifecycle. GPR data were collected in the form of B-scan, and time-domain analysis was used for post-processing. The results indicate (i) change of railway ballast RDP in time (long term); (ii) a dependency of ballast fouling level on RDP; and (iii) the RDP change during the ballast cleaning process, thus its efficiency. This research aimed to provide new perspectives into the decision-making process in initiating the mechanized ballast cleaning intervention based on the GPR-measured data.

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Dynamic Behavior in Transition Zones and Long-Term Railway Track Performance

Frontiers in Built Environment ◽

10.3389/fbuil.2021.658909 ◽

2021 ◽

Vol 7 ◽

Author(s):

André Paixão ◽

José Nuno Varandas ◽

Eduardo Fortunato

Keyword(s):

Three Dimensional ◽

Structural Response ◽

Railway Track ◽

Train Track ◽

3D Fem ◽

Transition Zones ◽

Complex Structural ◽

Three Dimensional Finite Element ◽

Long Term Behavior

Transition zones between embankments and bridges or tunnels are examples of critical assets of the railway infrastructure. These locations often exhibit higher degradations rates, mostly due to the development of differential settlements, which amplify the dynamic train-track interaction, thus further accelerating the development of settlements and deteriorating track components and vehicles. Despite the technical and scientific interest in predicting the long-term behavior of transition zones, few studies have been able to develop a robust approach that could accurately simulate this complex structural response. To address this topic, this work presents a three-dimensional finite element (3D FEM) approach to simulate the long-term behavior of railway tracks at transition zones. The approach considers both plastic deformation of the ballast layer using a high-cycle strain accumulation model and the non-linearity of the dynamic vehicle-track interaction that results from the evolution of the deformed states of the track itself. The results shed some light into the behavior of transition zones and evidence the complex long-term response of this structures and its interdependency with the transient response of the train-track interaction. Aspects that are critical when assessing the performance of these systems are analyzed in detail, which might be of relevance for researchers and practitioners in the design, construction, and maintenance processes.

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