scholarly journals A Numerical Study of the Screening Effectiveness of Open Trenches for High-Speed Train-Induced Vibration

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Chih-hung Chiang ◽  
Pei-hsun Tsai
Keyword(s):  
Poisson’S Ratio ◽  
High Speed ◽  
Numerical Study ◽  
Cutoff Frequency ◽  
Poisson's Ratio ◽  
High Speed Train ◽  
High Speed Rail ◽  
Train Speed ◽  
Open Trench ◽  
Screening Effectiveness

This study used the 2D boundary element method in time domain to examine the screening effectiveness of open trenches on reducing vibration generated by a high-speed train. The parameters included configurations of the trench, train speed, the distance between the source and the trench, and the Poisson’s ratio of the soil. A reducing displacement level (in dB scale) was defined and used to evaluate the screening effectiveness of a wave barrier. The maximal reducing displacement level reached 25 dB when an open trench was used as a wave barrier. The depth of an open trench is a main influential parameter of screening effectiveness. The cutoff frequency of the displacement spectrum increases with decreasing trench depth. The maximal screening effectiveness occurs when the depth is 0.3-0.4 Rayleigh wavelength. Using an open trench as a wave barrier can reduce 10–25 dB of vibration amplitude at frequencies between 30 and 70 Hz. A considerable increase in screening effectiveness of the open trench was observed from 30 to 70 Hz, which matches the main frequencies of vibration induced by Taiwan High Speed Rail. The influence of trench width on screening effectiveness is nonsignificant except for frequencies from 30 to 40 Hz. Poisson’s ratio has various effects on the reduction of vibration at frequencies higher than 30 Hz.

Out-of-Plane Responses of Overspeeding High-Speed Train on Curved Track

2018 ◽  
Vol 18 (11) ◽  
pp. 1850132 ◽  
Author(s):  
Jian Dai ◽  
Kok Keng Ang ◽  
Van Hai Luong ◽  
Minh Thi Tran ◽  
Dongqi Jiang
Keyword(s):  
High Speed ◽  
Numerical Study ◽  
Contact Forces ◽  
Railway Track ◽  
High Speed Train ◽  
Track Segment ◽  
Out Of Plane ◽  
Train Speed ◽  
Curved Track ◽  
Design Speed

This paper presents a numerical study on the out-of-plane responses of a high-speed train running on a curved railway track segment using the moving element method. The accuracy and efficiency of the proposed computation model presented herein are compared with available analytical results from the literature and a finite element solver based on a simplified moving load model. Thereafter, a half-railcar moving sprung-mass model and a double-rail track-foundation model are presented to investigate the behavior of a high-speed train traversing a curved track, particularly when the train speed is greater than the design speed of the curved track segment. The results show that the train speed and severity of track irregularity significantly affect the contact forces on the rails. This paper also presents a case of a railcar overturning when the train speed is greater than 2.5 times the design speed of a curved track segment.

Effects of Open Trench Dimension on Screening Effectiveness for High Speed Train Induced Vibration

2012 ◽  
Vol 256-259 ◽  
pp. 1187-1190 ◽  
Author(s):  
Pei Hsun Tsai
Keyword(s):  
Boundary Element Method ◽  
Time Domain ◽  
High Speed ◽  
Vibration Reduction ◽  
High Speed Train ◽  
Optimum Configuration ◽  
Maximum Reduction ◽  
Open Trench ◽  
Screening Effectiveness ◽  
Trench Width

2D boundary element method in time domain is used to investigate the screening effectiveness of open trenches on reducing vibration generated by a high speed train in this study. The parameter used in the study is the configurations of the trench. In order to evaluate the screening effectiveness of a wave barrier, a reduction of dB value is defined and used in this study. The maximum reduction of dB values is about 25 dB when an open trench is used as a wave barrier. The depth of open trench is a main influential parameter of screening effectiveness. The deeper the open trench, the better vibration reduction. The screening effectiveness increases slightly due to the increase of trench width. Current study facilitates the basics for the optimum configuration of the open trench as the wave barrier for reducing vibration.

Thermal comfort analysis of a high-speed train cabin considering the solar radiation effects

2019 ◽  
Vol 29 (8) ◽  
pp. 1101-1117
Author(s):  
Lin Yang ◽  
Xiangdong Li ◽  
Jiyuan Tu
Keyword(s):  
Solar Radiation ◽  
Thermal Comfort ◽  
High Speed ◽  
Radiation Effects ◽  
Numerical Study ◽  
Thermal Conditions ◽  
Long Distance ◽  
High Speed Rail ◽  
Hot Weather ◽  
Cabin Environment

Due to the fast development of high-speed rail (HSR) around the world, high-speed trains (HSTs) are becoming a strong competitor against airliners in terms of long-distance travel. Compared with airliner cabins, HST cabins have much larger window sizes. When the big windows provide better lighting and view of the scenery, they also have significant effects on the thermal conditions in the cabins due to the solar radiation through them. This study presents a numerical study on the solar radiation on the thermal comfort in a typical HST cabin. The effect of solar radiation was discussed in terms of airflow pattern, temperature distribution and thermal comfort indices. Parametric studies with seven different daytime hours were carried out. The effect of using the roller curtain was also studied. The overall cabin air temperature, especially near passengers, was found to have significantly increased by solar radiation. Passengers sitting next to windows were recorded to have an obvious thermal comfort variation at different hours of the day. To improve the passengers’ comfort and reduce energy consumption during hot weather, the use of a curtain could effectively reduce the solar radiation effect in the cabin environment.

scholarly journals Source Contribution Analysis for Exterior Noise of a High-Speed Train: Experiments and Simulations

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Jie Zhang ◽  
Xinbiao Xiao ◽  
Dewei Wang ◽  
Yan Yang ◽  
Jing Fan
Keyword(s):  
High Speed ◽  
Noise Source ◽  
High Speed Train ◽  
Noise Sources ◽  
Sound Sources ◽  
Lower Region ◽  
Source Contribution ◽  
Array Measurements ◽  
Noise Characteristics ◽  
Train Speed

This paper presents a detailed investigation into the contributions of different sound sources to the exterior noise of a high-speed train both experimentally and by simulations. The in situ exterior noise measurements of the high-speed train, including pass-by noise and noise source identification, are carried out on a viaduct. Pass-by noise characteristics, noise source localizations, noise source contributions of different regions, and noise source vertical distributions are considered in the data analysis, and it is shown how they are affected by the train speed. An exterior noise simulation model of the high-speed train is established based on the method of ray acoustics, and the inputs come from the array measurements. The predicted results are generally in good agreement with the measurements. The results show that for the high-speed train investigated in this paper, the sources with the highest levels are located at bogie and pantograph regions. The contributions of the noise sources in the carbody region on the pass-by noise increase with an increasing distance, while those in the bogie and train head decrease. The source contribution rates of the bogie and the lower region decrease with increasing train speed, while those of the coach centre increase. At a distance of 25 m, the effect of the different sound sources control on the pass-by noise is analysed, namely, the lower region, bogie, coach centre, roof region, and pantograph. This study can provide a basis for exterior noise control of high-speed trains.

Analysis on Dynamic Transfer Characteristics of Low Geosynthetic-Reinforced Embankments Supported by CFG Piles Subjected to High-Speed Railway

2011 ◽  
Vol 368-373 ◽  
pp. 2575-2580 ◽  
Author(s):  
Long Long Fu ◽  
Quan Mei Gong ◽  
Yang Wang
Keyword(s):  
Field Test ◽  
High Speed ◽  
Dynamic Stress ◽  
Numerical Study ◽  
High Stress ◽  
High Speed Train ◽  
High Speed Railway ◽  
Railway Line ◽  
Transfer Characteristics ◽  
Reinforced Embankments

To investigate the dynamic transfer characteristics of low geosynthetic-reinforced embankments supported by CFG piles under high-speed train load, a numerical study has been conducted through dynamic finite element method on basis of the dynamic field test on a cross-section of Beijing-Shanghai high-speed railway. The comparative analysis on results of numerical study and field test indicated the distribution characteristics of vertical dynamic stress induced by high-speed train load in subgrade soil under railway line. The numerical results also suggested a high stress area in subgrade where vertical dynamic stress is over 1kPa. Conclusions of this work can provide reference for both design and estimation of long-term settlement of low geosynthetic-reinforced embankments supported by CFG piles for high-speed railway.

scholarly journals The Effect of Pendolino high-speed rail on the structure of buildings located in the proximity of railway tracks

2016 ◽  
Vol 21 (1) ◽  
pp. 231-238
Author(s):  
K. Grębowski ◽  
Z. Ulman
Keyword(s):  
Dynamic Analysis ◽  
High Speed ◽  
Building Structure ◽  
High Speed Train ◽  
High Speed Rail ◽  
Railway Tracks ◽  
High Speed Trains ◽  
Railway System ◽  
The Subject ◽  
The Impact

Abstract The following research focuses on the dynamic analysis of impact of the high-speed train induced vibrations on the structures located near railway tracks. The office complex chosen as the subject of calculations is located in the northern part of Poland, in Gdańsk, in the proximity of Pendolino, the high speed train route. The high speed trains are the response for the growing needs for a more efficient railway system. However, with a higher speed of the train, the railway induced vibrations might cause more harmful resonance in the structures of the nearby buildings. The damage severity depends on many factors such as the duration of said resonance and the presence of additional loads. The studies and analyses helped to determinate the method of evaluating the impact of railway induced vibrations on any building structure. The dynamic analysis presented in the research is an example of a method which allows an effective calculation of the impact of vibrations via SOFISTIK program.

Probabilistic Analysis of Flying Ballast on High-Speed Rail Lines

2017 ◽  
Author(s):  
Jieyi Deng ◽  
Guoqing Jing ◽  
Xiang Liu
Keyword(s):  
Risk Factors ◽  
High Speed ◽  
Safety Concern ◽  
Rolling Stock ◽  
Probabilistic Assessment ◽  
High Speed Train ◽  
Modeling Framework ◽  
High Speed Rail ◽  
Rail Systems ◽  
Ballasted Track

Safety is a top priority for the development of worldwide high-speed rail systems. Ballast flying is a particular safety concern when a high-speed train is traveling above a certain speed on the ballasted track. Displaced ballast particles from the track may cause damages to rolling stock, as well as the track infrastructure and wayside structures close to the sides of way. The objective of this research is to develop a probabilistic modeling framework to estimate the probability of ballast flight on specific segments or routes, accounting for several principal risk factors. Based on the probabilistic assessment, we propose a methodology to quantify the probability of flying ballast under certain scenarios. The methodology can be further developed, ultimately enabling a normative risk assessment for flying ballast risk management.

A Study on Speed Elevation Possibility at the Connection between High Speed Lines and Conventional Lines with Korean High Speed Train

2006 ◽  
Vol 326-328 ◽  
pp. 635-638 ◽  
Author(s):  
Young Sam Ham ◽  
Jai Sung Hong
Keyword(s):  
Contact Force ◽  
High Speed ◽  
Integrated System ◽  
Communication Line ◽  
Mass Transportation ◽  
Test Results ◽  
High Speed Train ◽  
Safety Standards ◽  
Derailment Coefficient ◽  
Train Speed

Railways are a mass transportation system with high safety and punctuality. These strengths have been well proved by tests and evaluations. Railways are an integrated system with cars, power, signal, communication, line structures and operation. Among many safety standards of these systems, contact force between wheels and lines can be chosen since a derailment coefficient evaluated by contract force is the most important fact that decides the safety of railways. Especially regarding express trains, since they run twice faster than conventional ones, the evaluation of a derailment coefficient is more important than any other criteria. Currently, Korean express trains between Seoul and Pusan use the same stations as conventional trains in Daejeon and Dong-Daegu; therefore, express trains run on conventional lines from express lines. This paper describes test results acquired by increasing the train speed where express lines and conventional lines are connected. Test results tell that it is safe with under 0.8 derailment coefficient and running time is reduced by 10~30 seconds in each section.

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