scholarly journals Experimental settlement and dynamic behavior of a portion of ballasted railway track under high speed trains

2008 ◽  
Vol 316 (1-5) ◽  
pp. 211-233 ◽  
Author(s):  
A. Al Shaer ◽  
D. Duhamel ◽  
K. Sab ◽  
G. Foret ◽  
L. Schmitt
Keyword(s):  
Dynamic Behavior ◽  
High Speed ◽  
Railway Track ◽  
High Speed Trains

A multi-sensor fusion framework for detecting small amplitude hunting of high-speed trains

2018 ◽  
Vol 24 (17) ◽  
pp. 3797-3808 ◽  
Author(s):  
Jing Ning ◽  
Qi Liu ◽  
Huajiang Ouyang ◽  
Chunjun Chen ◽  
Bing Zhang
Keyword(s):  
Monitoring System ◽  
Sensor Fusion ◽  
Small Amplitude ◽  
High Speed ◽  
Railway Track ◽  
Support Vector ◽  
Monitoring Systems ◽  
Operation Condition ◽  
High Speed Trains ◽  
Fusion Framework

Hunting monitoring is very important for high-speed trains to achieve safe operation. But all the monitoring systems are designed to detect hunting only after hunting has developed sufficiently. Under these circumstances, some damage may be caused to the railway track and train wheels. The work reported in this paper aims to solve the detection problem of small amplitude hunting before the lateral instability of high-speed trains occurs. But the information from a single sensor can only reflect the local operation state of a train. So, to improve the accuracy and robustness of the monitoring system, a multi-sensor fusion framework for detecting small amplitude hunting of high-speed trains based on an improved Dempster–Shafer (DS) theory is proposed. The framework consists of a series of steps. Firstly, the method of combining empirical mode decomposition and sample entropy is used to extract features of each operation condition. Secondly, the posterior probability support vector machine is used to get the basic probability assignment. Finally, the DS theory improved by the authors is proposed to get a more accurate detection result. This framework developed by the authors is used on high-speed trains with success and experimental findings are provided. This multi-sensor fusion framework can also be used in other condition monitoring systems on high-speed trains, such as the gearbox monitoring system, from which nonstationary signals are acquired too.

scholarly journals Ground-Based Radar Interferometry for Monitoring the Dynamic Performance of a Multitrack Steel Truss High-Speed Railway Bridge

2020 ◽  
Vol 12 (16) ◽  
pp. 2594
Author(s):  
Qihuan Huang ◽  
Yian Wang ◽  
Guido Luzi ◽  
Michele Crosetto ◽  
Oriol Monserrat ◽  
...  
Keyword(s):  
Dynamic Behavior ◽  
High Speed ◽  
Point Clouds ◽  
Vibration Monitoring ◽  
Dynamic Monitoring ◽  
Railway Bridge ◽  
High Speed Railway ◽  
Testing Procedures ◽  
Microwave Radar ◽  
High Speed Trains

With the continuous expansion of the high-speed railway network in China, long-span railway bridges carrying multiple tracks demand reliable and fast testing procedures and techniques. Bridge dynamic behavior analysis is a critical process in ensuring safe operation of structures. In this study, we present some experimental results of the vibration monitoring of a four-track high-speed railway bridge with a metro–track on each side: the Nanjing–Dashengguan high-speed railway bridge (NDHRB). The results were obtained using a terrestrial microwave radar interferometer named IBIS-S. The radar measurements were interpreted with the support of lidar point clouds. The results of the bridge dynamic response under different loading conditions, including high-speed trains, metro and wind were compared with the existing bridge structure health monitoring (SHM) system, underlining the high spatial (0.5 m) and temporal resolutions (50 Hz–200 Hz) of this technique for railway bridge dynamic monitoring. The detailed results can help engineers capturing the maximum train-induced bridge displacement. The bridge was also monitored by the radar from a lateral position with respect to the bridge longitudinal direction. This allowed us to have a more exhaustive description of the bridge dynamic behavior. The different effects induced by the passage of trains through different tracks and directions were distinguished. In addition, the space deformation map of the wide bridge deck under the eccentric load of trains, especially along the lateral direction (30 m), can help evaluating the running stability of high-speed trains.

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

2019 ◽  
Vol 19 (09) ◽  
pp. 1950111 ◽  
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.

scholarly journals Annoyance Based Vibro-Acoustic Comfort Evaluation of as Summation of Stimuli Annoyance in the Context of Human Exposure to Noise and Vibration in Buildings

2020 ◽  
Vol 12 (23) ◽  
pp. 9876
Author(s):  
Krzysztof Nering ◽  
Alicja Kowalska-Koczwara ◽  
Krzysztof Stypuła
Keyword(s):  
High Speed ◽  
Residential Building ◽  
Railway Track ◽  
Simultaneous Occurrence ◽  
Noise And Vibration ◽  
Noise Current ◽  
Railway Line ◽  
High Speed Trains ◽  
Acoustic Comfort ◽  
The City

This paper presents the issues of assessing the comfort of people staying indoors who are exposed to vibrations and material noise caused by vibrations of partitions like floors and walls (ground-borne noise). Current criteria in the evaluation of vibrational and acoustic comfort cannot be assessed in the context of the simultaneous occurrence of stimuli such as noise and vibration. Railway transport, including passenger and cargo transport, is becoming increasingly prevalent, and new railway lines are being planned for environmental reasons. Sometimes, there are changes in stimuli produced by existing railway lines. For example, high-speed trains appear on an old railway track. Such a situation appeared on the Central Railway Line in Poland, which is still used by old trains, yet its operator plans to raise their speed limits. The analysis of the problem of the simultaneous occurrence of stimuli presented in this paper was based on measurements performed in a residential building located near the Central Railway Main Line in the city Zawiercie. Noise and vibration as the analyzed stimuli in both cases meet comfort requirements, yet when exposure to two stimuli was considered, comfort may be at risk.

Rigid-Mass Vehicle Model for Identification of Bridge Frequencies Concerning Pitching Effect

2019 ◽  
Vol 19 (02) ◽  
pp. 1950008 ◽  
Author(s):  
Judy P. Yang ◽  
Bo-Lin Chen
Keyword(s):  
Dynamic Behavior ◽  
High Speed ◽  
Vehicle Body ◽  
Moving Loads ◽  
Vehicle Model ◽  
Test Vehicle ◽  
Single Degree Of Freedom ◽  
Proposed Model ◽  
High Speed Trains ◽  
Rigid Mass

The concept of vehicle-bridge interaction (VBI) was originally developed to investigate the dynamic behavior of bridges subjected to moving loads such as high-speed trains. In recent years, the VBI system was introduced to further explore the possibility of identifying bridge frequencies in order to monitor the health of bridges via the use of passing vehicles. Among the models of test vehicles, the sprung mass vehicle model with a single-degree-of-freedom vehicle body is the most common adopted one due to its simplicity. Nevertheless, for a test vehicle moving over the uneven pavement, the pitching effect arising from the vertical and rotational movements of the vehicle actually influences the identification of bridge frequencies. As such, a rigid-mass vehicle model is proposed in this work to improve the sprung mass vehicle model by including both vertical and rotational deflections. The analytical solutions to the rigid-mass VBI system are derived to verify the proposed model, and the numerical examples are provided to investigate the dynamic behavior of the VBI system subjected to road irregularity.

scholarly journals Vehicle-bridge interaction system

2018 ◽  
Vol 239 ◽  
pp. 05004
Author(s):  
Daria Provornaya ◽  
Sergey Glushkov
Keyword(s):  
High Speed ◽  
Resonance Condition ◽  
Resonance Effect ◽  
Excitation Frequency ◽  
Railway Track ◽  
The Road ◽  
Moving Vehicles ◽  
High Speed Trains ◽  
On The Road ◽  
Oscillation Frequencies

One of the problems in high-speed railways is the influence and vibrations of bridges caused by moving trains. This problem significantly differs from the problems of road bridges for the following reasons. Firstly, the loads caused by the moving train on the bridge are repeated in nature, as a consecutively rotating loads (wheel), implying that certain frequencies will be caused on the bridge during the passage of the train. In contrast, the loads implied on the road are random in nature, expressed through wheel loads and the distance between the wheels. Secondly, high-speed trains can move at a speed much higher than vehicles moving along the road, which makes it possible for the excitation frequency to coincide with the oscillation frequencies of the bridge, which leads to the so-called resonance effect. Whenever the resonance condition is reached, the reaction of the bridge will be constantly amplified, since there are heavy moving loads passing through the bridge. This effect could hardly be observed on road bridges. Thirdly, the mass ratio of vehicles on the bridge is usually larger due to the fact that the train consists of several coupled cars and the railway track is relatively narrow, it has no more than two tracks in most cases. In contrast, a road bridge may be so large that it can afford four or more lanes for vehicles moving in the opposite direction. For this reason, the interaction between moving vehicles causes a greater reaction for the road bridge than for the railways.

scholarly journals Application Study on Fiber Optic Monitoring and Identification of CRTS-II-Slab Ballastless Track Debonding on Viaduct

2021 ◽  
Vol 11 (13) ◽  
pp. 6239
Author(s):  
Gaoran Guo ◽  
Junfang Wang ◽  
Bowen Du ◽  
Yanliang Du
Keyword(s):  
High Speed ◽  
Ride Comfort ◽  
Railway Track ◽  
Monitoring Scheme ◽  
Ballastless Track ◽  
Site Monitoring ◽  
Track System ◽  
High Speed Trains ◽  
Debonding Detection ◽  
Initial Difference

China Railway Track System (CRTS)-II-slab ballastless track is a new type of track structure, and its interlayer connection state is considerably important for the operation safety and ride comfort of high-speed trains. However, the location and multiple influencing factors of interlayer debonding lead to difficulties in monitoring and identification. Here, the research on the design and application of a monitoring scheme that facilitates interlayer debonding detection of ballastless track and an effective indicator for debonding identification and assessment is proposed. The results show that on-site monitoring can effectively capture the vibration signals caused by train vibration and interlayer debonding. The features of the data acquired in the situations with and without interlayer debonding are compared after instantaneous baseline validation. Some significant features capable of obviously differentiating a debonding state from the normal state are identified. Furthermore, a new indicator, combining multiple debonding-sensitive features by similarity-based weights normalizing the initial difference between mutual instantaneous baselines, is developed to support rational and comprehensive assessment quantitatively. The contribution of this study includes the development and application of an interlay-debonding monitoring scheme, the establishment of an effective-feature pool, and the proposal of the similarity-based indicator, thereby laying a good foundation for debonding identification of ballastless track.

Effects of shear keys and track system on the behavior of simply-supported bridges for high-speed trains subjected to transverse earthquake excitations

2021 ◽  
pp. 136943322110073
Author(s):  
Dongliang Meng ◽  
Shizai Chen ◽  
Menggang Yang ◽  
Shangtao Hu
Keyword(s):  
Seismic Behavior ◽  
High Speed ◽  
Bridge Piers ◽  
Railway Track ◽  
Seismic Responses ◽  
Short Side ◽  
Simply Supported ◽  
Track System ◽  
Shear Keys ◽  
High Speed Trains

China railway track system II (CRTS-II) slab ballastless track is usually constructed on high-speed railway (HSR) bridges to ensure the rail smoothness and the running safety of high-speed trains, but the use of the longitudinal continuous track system would significantly alter the dynamic characteristics of the bridges and therefore influence the bridge seismic responses. The pounding at shear keys has also been identified as one of the critical factors affecting the seismic behavior of bridges. To investigate the effects of shear keys and CRTS-II track system on the seismic behavior of HSR simply-supported bridges subjected to transverse earthquake excitations, detailed 3D finite element models are developed by using ABAQUS. The seismic responses calculated from the bridges with and without considering shear keys are firstly compared. The result shows that the shear keys can effectively limit the development of pier-girder relative displacement and thus decrease the potential of girder dislocation. However, large pounding forces would be generated between the shear keys and bearing pads and transferred to bridge piers, which will amplify the seismic responses of the bridge piers. The result of seismic analyses of multiple-span simply-supported bridges with and without considering the track system shows that the track system will significantly influence the distribution of seismic forces among the bridge spans. For a bridge with equal pier heights, considering the track system will reduce the seismic responses of side spans (close to subgrade) but will increase those of the middle spans. Whereas an opposite trend is found for bridges with high middle piers and short side piers.

scholarly journals Dynamic Performance of High-Speed Rail Cable Stayed Bridge with Altered Track Assembly

2020 ◽  
Vol 8 (5) ◽  
pp. 1532-1539
Keyword(s):  
High Speed ◽  
Dynamic Performance ◽  
Element Model ◽  
Railway Track ◽  
Efficient Design ◽  
High Speed Rail ◽  
Cable Stayed Bridge ◽  
Ballasted Track ◽  
High Speed Trains ◽  
European Standards

On fast moving world, the interest is being increased for high-speed trains. It provides a sustainable and effective mode of travelling. Till date India was special among the developing nations for not having a high-speed rail corridor. However, by introducing Mumbai–Ahmedabad high-speed rail corridor, it opens up research directed towards efficient design of the supporting structures. In India, construction and upgradation of railways on its top which attracts the researchers for advance research in the same field. Here an attempt is made to understand the railway track formulation and bridging aspect for high speed rail model as per European standards to assess the influence or impact of rail axle load on bridge behavior. Under this scope, a hypothetical case study of “H-Shaped Cable Stayed Bridge” is taken with Rheda 2000 non-ballasted track, vibrating and non-vibrating ballasted track. The analysis is performed by two approaches; first is the track characterized by its finite element model and second is by introducing track through its equivalent weight. The ballast-less track is already a candid approach for rail lines, showing competitiveness against the conventional ballasted track. The reason for the adaptability of the Ballast-less track is its low maintenance and high accessibility of materials. However, on the basis of vibration analysis “Vibrating Ballasted Track” proved decent in terms of performance.

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