Dynamic responses of Tsing Ma Bridge and running safety of trains subjected to Typhoon York

2013 ◽  
Vol 1 (3) ◽  
pp. 181-192 ◽  
Author(s):  
W.W. Guo ◽  
H. Xia ◽  
N. Zhang
Keyword(s):  
Dynamic Responses ◽  
Running Safety ◽  
Tsing Ma Bridge

Dynamic analysis of coupled train–track–bridge system subjected to debris flow impact

2018 ◽  
Vol 22 (4) ◽  
pp. 919-934 ◽  
Author(s):  
Xun Zhang ◽  
Zhipeng Wen ◽  
Wensu Chen ◽  
Xiyang Wang ◽  
Yan Zhu
Keyword(s):  
Debris Flow ◽  
Dynamic Analysis ◽  
High Speed ◽  
Impact Load ◽  
Dynamic Responses ◽  
Train Track ◽  
Running Safety ◽  
Track Bridge ◽  
Safety Indices ◽  
Bridge System

With the increasing popularity of high-speed railway, more and more bridges are being constructed in Western China where debris flows are very common. A debris flow with moderate intensity may endanger a high-speed train traveling on a bridge, since its direct impact leads to adverse dynamic responses of the bridge and the track structure. In order to address this issue, a dynamic analysis model is established for studying vibrations of coupled train–track–bridge system subjected to debris flow impact, in which a model of debris flow impact load in time domain is proposed and applied on bridge piers as external excitation. In addition, a six-span simply supported box girder bridge is considered as a case study. The dynamic responses of the bridge and the running safety indices such as derailment factor, offload factor, and lateral wheel–rail force of the train are investigated. Some influencing factors are then discussed based on parametric studies. The results show that both bridge responses and running safety indices are greatly amplified due to debris flow impact loads as compared with that without debris flow impact. With respect to the debris flow impact load, the boulder collision has a more negative impact on the dynamic responses of the bridge and train than the dynamic slurry pressure. Both the debris flow impact intensity and train speed determine the running safety indices, and the debris flow occurrence time should be also carefully considered to investigate the worst scenario.

scholarly journals Dynamic Responses of Vehicle-CRTS III Slab Track System and Vehicle Running Safety Subjected to Uniform Seismic Excitation

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Ping Lou ◽  
Kailun Gong ◽  
Chen Zhao ◽  
Qingyuan Xu ◽  
Robert K. Luo
Keyword(s):  
Reduction Rate ◽  
Seismic Intensity ◽  
Dynamic Responses ◽  
Seismic Excitation ◽  
Wheel Load ◽  
Running Speed ◽  
Running Safety ◽  
Slab Track ◽  
Track System ◽  
Highly Sensitive

The dynamic model for the vehicle-CRTS III slab track system is established subjected to uniform seismic excitation, and the calculation program with MATLAB is compiled and verified. The influences of track parameters, seismic intensity, and running speed of the vehicle on the dynamic responses of the system and the vehicle running safety are analyzed. The results show that (1) the track parameters have certain influence on the dynamic responses of the system, and the seismic intensity and the running speed of the vehicle have important influence on the vehicle running safety; (2) the derailment coefficient is highly sensitive to seismic intensity, and the wheel load reduction rate is also highly sensitive to the running speed of the vehicle.

Mapping relationship between dynamic responses of high-speed trains and additional bridge deformations

2020 ◽  
pp. 107754632093689
Author(s):  
Hongye Gou ◽  
Chang Liu ◽  
Hui Hua ◽  
Yi Bao ◽  
Qianhui Pu
Keyword(s):  
High Speed ◽  
Coupled Model ◽  
Dynamic Responses ◽  
High Speed Railway ◽  
Railway Bridges ◽  
Running Safety ◽  
High Speed Trains ◽  
Track Bridge ◽  
The Relationship ◽  
Track Deformation

Deformations of high-speed railways accumulate over time and affect the geometry of the track, thus affecting the running safety of trains. This article proposes a new method to map the relationship between dynamic responses of high-speed trains and additional bridge deformations. A train–track–bridge coupled model is established to determine relationship between the dynamic responses (e.g. accelerations and wheel–rail forces) of the high-speed trains and the track deformations caused by bridge pier settlement, girder end rotation, and girder camber. The dynamic responses are correlated with the track deformation. The mapping relationship between bridge deformations and running safety of trains is determined. To satisfy the requirements of safety and riding comfort, the suggested upper thresholds of pier settlement, girder end rotation, and girder camber are 22.6 mm, 0.92‰ rad, and 17.2 mm, respectively. This study provides a method that is convenient for engineers in evaluation and maintenance of high-speed railway bridges.

Stochastic Analysis of Vehicle-Bridge Coupled Interaction and Uncertainty Bounds of Random Responses in Heavy Haul Railways

2019 ◽  
Vol 19 (12) ◽  
pp. 1950144
Author(s):  
Jianfeng Mao ◽  
Zhiwu Yu ◽  
Lizhong Jiang
Keyword(s):  
Probability Distribution ◽  
Safety Assessment ◽  
Structural Parameters ◽  
Time History ◽  
Coupled System ◽  
Dynamic Responses ◽  
Running Safety ◽  
Heavy Haul ◽  
Vehicle Loads ◽  
Random Responses

The systematic running safety assessment of railway bridges presents lots of challenges, one of which is estimating the uncertainty bounds of the structural responses of bridges under vehicle loads with multisource randomness. In this study, a probability safety assessment method is proposed for evaluating the uncertainty bounds of random time-history responses for the stochastic train-bridge coupled system. First, a refined probabilistic model for the train-bridge coupled system (TBS) in heavy haul railway is established with the multi-excitations of random track irregularities, random vehicle loads and stochastic structural parameters. The probability density evolution method (PDEM) is employed to obtain the solution of the time-varying probability transferred between the stochastic excitations and the output of the dynamic responses. Then, to establish a rapid and straightforward approach for the systematic running safety assessment of the TBS, the quantiles of the probability distribution are used to estimate the time-history uncertainty bounds of random responses of interest distributed in real probability functions. Case studies by the field test and numerical simulation are presented to verify and investigate the accuracy and reliability of the proposed method. The results show that the quantiles of the probability distribution proposed are suitable for the systematic running safety assessment of the TBS.

scholarly journals Running Safety of Trains under Vessel-Bridge Collision

2015 ◽  
Vol 2015 ◽  
pp. 1-11
Author(s):  
Yongle Li ◽  
Jiangtao Deng ◽  
Bin Wang ◽  
Chuanjin Yu
Keyword(s):  
Element Model ◽  
Dynamic Responses ◽  
Lateral Acceleration ◽  
Vertical Acceleration ◽  
Running Safety ◽  
Derailment Coefficient ◽  
Parametric Studies ◽  
Train Speed ◽  
Unloading Rate ◽  
Bridge System

To optimize the sensor placement of the health monitoring system, the dynamic behavior of the train-bridge system subjected to vessel-collision should be studied in detail firstly. This study thus focuses on the characteristics of a train-bridge system under vessel-bridge collision. The process of the vessel-bridge collision is simulated numerically with a reliable finite element model (FEM). The dynamic responses of a single car and a train crossing a cable-stayed bridge are calculated. It is shown that the collision causes significant increase of the train’s lateral acceleration, lateral wheelset force, wheel unloading rate, and derailment coefficient. The effect of the collision on the train’s vertical acceleration is much smaller. In addition, parametric studies with various train’s positions, ship tonnage, and train speed are performed. If the train is closer to the vessel-bridge collision position or the ship tonnage is larger, the train will be more dangerous. There is a relatively high probability of running danger at a low speed, resulting from longer stay of the train on the bridge. The train’s position, the ship tonnage, and the train speed must be considered when determining the most adverse conditions for the trains running on bridges under vessel-bridge collision.

Seismic Design Research of Simply Supported Rail-Bridge Based on Running Safety

2014 ◽  
Vol 1065-1069 ◽  
pp. 962-968
Author(s):  
Yan Han ◽  
Xiao Dong Wang
Keyword(s):  
Seismic Design ◽  
Traffic Safety ◽  
Interpolation Method ◽  
Spectral Characteristics ◽  
Dynamic Responses ◽  
Response Analysis ◽  
Analysis Model ◽  
Running Safety ◽  
Simply Supported ◽  
Bridge System

To explore the practical rail-bridge seismic design methods, dynamic response analysis model of the train-rail-bridge system under seismic loads was established, and the widely used simply supported track-bridge in rail transport was taken for the study. By inputting different intensity and frequency artificial seismic waves to the train-rail-bridge system, the whole history of the vehicles running through the bridge is simulated and the dynamic responses of the bridge and the vehicles are calculated. The influence of train type, seismic intensity and spectral characteristics of the earthquake were analyzed. Taking Japanese traffic safety evaluation indexes including derailment coefficient, wheel offload rate and lateral wheel-rail force as evaluation criteria, the allowed lateral bridge displacement limits and acceleration limits that ensuring train running safety under earthquake were obtained, and the bridge vibration limit curve was drawn. Using Lagrange interpolation method, the mathematical expression of the curve was worked out, which can provide a reference to rail-bridge aseismic design.

Random Analysis of the Safety of a High-Speed Train through a Bridge under Earthquake

2019 ◽  
Author(s):  
Dong-Ho Choi ◽  
Di Mu ◽  
Chunyan Ma ◽  
Min-Wo Park ◽  
Ji-Hoon Lim
Keyword(s):  
High Speed ◽  
Damping Ratio ◽  
Time Lag ◽  
Dynamic Responses ◽  
Cost Calculation ◽  
Load Factor ◽  
High Speed Train ◽  
Three Dimensional Model ◽  
Research Attention ◽  
Running Safety

<p>The widely use of bridge structures in modern high-speed railway makes the possibility that a train face to an earthquake when it’s running on a bridge increased. The running safety of the train requires more research attention to be paid. This study investigated the effect of bridge properties on the running safety of a high- speed train under earthquakes using a fast calculation approach. The train-track-bridge (TTB) system is simplified as a three-dimensional model for the dynamic analysis. The rigid contact between rails and wheels is considered, while the direct coupling iteration approach is adopted to solve the dynamic responses of the TTB system. The track irregularities, wheel hunting motion, and multi-support earthquake, which considers the time lag between the seismic waves at different supports, are considered as the excitations to the TTB system. The randomness of the excitations is considered by the pseudo-excitation method (PEM) and the statistical results of the TTB system random responses are obtained. The derailment factor and the off-load factor are used to evaluate the running safety of the train. In the case study, the damping ratio, pier height, and track eccentricity are considered as the various parameters of the bridge properties. Through the PEM analysis, the mean value and standard deviation of the running safety factors were obtained used to evaluate the running safety of the train under an earthquake condition. The evaluation approach for the running safety used in this study can help the engineers to simply check the designs of the railway bridges without performing large time cost calculation work.</p>

Running Safety Assessment of Trains on Bridges under Earthquakes Based on Spectral Intensity Theory

2021 ◽  
Author(s):  
Wei Guo ◽  
Yang Wang ◽  
Hanyun Liu ◽  
Yan Long ◽  
Lizhong Jiang ◽  
...  
Keyword(s):  
High Speed ◽  
Safety Assessment ◽  
Low Frequency ◽  
Interaction Model ◽  
Spectral Intensity ◽  
Dynamic Responses ◽  
Running Safety ◽  
High Speed Trains ◽  
Track Bridge ◽  
Multi Body

The main goal of this paper is to perform the safety assessment of high-speed trains (HSTs) on the simply supported bridges (SSBs) under low-level earthquakes, which are frequently encountered by HSTs, utilizing spectral intensity (SI) index. First, the HST’s limit displacements, which are calculated by using the multi-body train model with detailed wheel–rail relationship, varying with train speed, frequency and amplitude of a sinusoidal base excitation are obtained. Then, based on the obtained HST’s limit displacements, the spectral intensity limits (SIL) graded by the train’s running speed are calculated, and the relationship between the bridge seismic dynamic responses and the train’s running safety was established. Next, the method that utilizes the SI and the SIL indexes to evaluate the HST’s running safety was proposed and verified by comparing with the evaluation result of the train–track–bridge interaction model. Based on the proposed SI index, the HST’s running safety on the SSBs was evaluated under earthquakes, considering different pier heights and site types. The results showed that the low-frequency components of the ground motions are unfavorable to the HST’s running safety, and the height of bridge piers has a significant impact on running safety.

EFFECT OF TRUCK COLLISION ON DYNAMIC RESPONSE OF TRAIN–BRIDGE SYSTEMS AND RUNNING SAFETY OF HIGH-SPEED TRAINS

2013 ◽  
Vol 13 (03) ◽  
pp. 1250064 ◽  
Author(s):  
CHAOYI XIA ◽  
HE XIA ◽  
NAN ZHANG ◽  
WEIWEI GUO
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
Dynamic Responses ◽  
Illustrative Case ◽  
Analysis Model ◽  
Box Girders ◽  
Running Safety ◽  
High Speed Trains ◽  
Safety Indices

A dynamic analysis model is established for a coupled high-speed train and bridge system subjected to collision loads. A 5 × 32 m continuous high-speed railway bridge with PC box girders is considered in the illustrative case study. Entire histories of a CRH2 high-speed EMU train running on the bridge are simulated when the truck collision load acts on the bridge pier, from which the dynamic responses such as displacements and accelerations of the bridge, and the running safety indices such as derailment factors, offload factors and lateral wheel/rail forces of the train are computed. For the case study, the running safety indices of the train at different speeds on the bridge when its pier is subjected to a truck collision with different intensities are compared with the corresponding allowances of the Chinese Codes. The results show that the dynamic response of the bridge subjected to truck collision loads is much greater than the one without collision, which can drastically influence the running safety of high-speed trains.

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