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 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.

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

Moving element analysis of discretely supported high-speed rail systems

2017 ◽  
Vol 232 (3) ◽  
pp. 783-797 ◽  
Author(s):  
Jian Dai ◽  
Kok Keng Ang ◽  
Minh Thi Tran ◽  
Van Hai Luong ◽  
Dongqi Jiang
Keyword(s):  
High Speed ◽  
Railway Track ◽  
High Speed Train ◽  
Element Analysis ◽  
High Speed Rail ◽  
Mass System ◽  
Rail System ◽  
Rail Systems ◽  
Track System ◽  
The Difference

In this paper, a computational scheme in conjunction with the moving element method has been proposed to investigate the dynamic response of a high-speed rail system in which the discrete sleepers on the subgrade support the railway track. The track foundation is modeled as a beam supported by uniformly spaced discrete spring-damper units. The high-speed train is modeled as a moving sprung-mass system that travels over the track. The effect of the stiffness of the discrete supports, train speed, and railhead roughness on the dynamic behavior of the train–track system has been investigated. As a comparison, the response of a continuously supported high-speed rail system that uses a foundation stiffness equivalent to that of a discretely supported track has been obtained. The difference in results between the “equivalent” continuously supported and the discretely supported high-speed rails has been compared and discussed. In general, the study found that a high-speed train that travels over a discretely supported track produces more severe vibrations than that travels over a continuously supported track of equivalent foundation stiffness.

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 Polygonisation of railway wheels: a critical review

2020 ◽  
Vol 28 (4) ◽  
pp. 317-345 ◽  
Author(s):  
Gongquan Tao ◽  
Zefeng Wen ◽  
Xuesong Jin ◽  
Xiaoxuan Yang
Keyword(s):  
Critical Review ◽  
High Speed ◽  
Natural Vibration ◽  
Ride Comfort ◽  
Railway Vehicle ◽  
Formation Mechanisms ◽  
Simulation Methods ◽  
Track System ◽  
High Speed Trains ◽  
Railway Wheels

AbstractPolygonisation is a common nonuniform wear phenomenon occurring in railway vehicle wheels and has a severe impact on the vehicle–track system, ride comfort, and lineside residents. This paper first summarizes periodic defects of the wheels, including wheel polygonisation and wheel corrugation, occurring in railways worldwide. Thereafter, the effects of wheel polygonisation on the wheel–rail interaction, noise and vibration, and fatigue failure of the vehicle and track components are reviewed. Based on the different causes, the formation mechanisms of periodic wheel defects are classified into three categories: (1) initial defects of wheels, (2) natural vibration of the vehicle–track system, and (3) thermoelastic instability. In addition, the simulation methods of wheel polygonisation evolution and countermeasures to mitigate wheel polygonisation are presented. Emphasis is given to the characteristics, effects, causes, and solutions of wheel polygonisation in metro vehicles, locomotives, and high-speed trains in China. Finally, the guidance is provided on further understanding the formation mechanisms, monitoring technology, and maintenance criterion of wheel polygonisation.

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.

scholarly journals Numerical analysis of beam rail bridges with random track irregularities

2018 ◽  
Vol 196 ◽  
pp. 01050
Author(s):  
Monika Podwórna
Keyword(s):  
Numerical Analysis ◽  
High Speed ◽  
Concrete Bridges ◽  
Track Structure ◽  
Simply Supported ◽  
Ballasted Track ◽  
High Speed Trains ◽  
Composite Bridge ◽  
Random Track Irregularities ◽  
Track Irregularities

The study focuses on dynamic analysis of composite bridge / track structure / train systems (BTT systems) with random vertical track irregularities taken into consideration. The paper presents the results of numerical analysis of advanced virtual models of series-of-types of single-span simply-supported railway steel-concrete bridges (SCB) with symmetric platforms, located on lines with the ballasted track structure adapted to traffic of high-speed trains.

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