Temperature effect on service performance of high-speed railway concrete bridges

2016 ◽  
Vol 20 (6) ◽  
pp. 865-883 ◽  
Author(s):  
Y Tian ◽  
N Zhang ◽  
H Xia
Keyword(s):  
Temperature Effect ◽  
High Speed ◽  
Low Frequency ◽  
Numerical Approach ◽  
Service Performance ◽  
Dynamic Responses ◽  
Temperature Fields ◽  
Coupled Analysis ◽  
Element Analysis ◽  
High Speed Railway

Non-uniform temperature fields induced by time-varying solar position and heat exchange are of great significance for the bridge safety. The accurate identifications of these changes are necessary to avoid unexpected deformations and the loss of service performance. This article presents a numerical approach to determine temperature effects on train–bridge-coupled dynamics. Heat flux density of different components of a 32-m simply supported concrete bridge on high-speed railway is calculated, in which a section segmentation method is adopted for simplifications of boundary conditions. Based on heat–stress-coupled technology, temperature fields and deformation fields of the bridge are then computed via finite element analysis. Combining track irregularities and its thermal deformation as external excitations, the train–bridge-coupled analysis is solved by an inter-system iteration method. Dynamic responses of bridge and train are compared to those obtained neglecting the temperature effect. Comparative studies illustrate that temperature effect has major impacts on the bridge displacement due to the increase in low-frequency components of excitations. For the train, lateral responses are more obvious. Maximum derail factor and lateral wheel–rail force occur when the train leaves from the bridge.

Study on Influences of Thickness of Flange of U Rib on Mechanical Behaviors of Orthotropic Monolithic Steel Bridge Deck System

2010 ◽  
Vol 163-167 ◽  
pp. 122-126 ◽  
Author(s):  
Ru Deng Luo ◽  
Mei Xin Ye ◽  
Ye Zhi Zhang
Keyword(s):  
Finite Element Analysis ◽  
Yangtze River ◽  
High Speed ◽  
Bridge Deck ◽  
Steel Bridges ◽  
Engineering Practice ◽  
Steel Bridge ◽  
Mechanical Behaviors ◽  
Element Analysis ◽  
High Speed Railway

Orthotropic monolithic steel bridge deck system stiffened by U rib is very fit for high-speed railway steel bridges because of its excellent mechanical behaviors. Thickness of flange is a very important parameter of U rib and has influence on mechanical behaviors of orthotropic monolithic steel bridge deck system. Based on the engineering practice of Anqing Yangtze River Railway Grand Bridge, the kind and the extents of influences of thickness of flange of U rib on mechanical behaviors of orthotropic monolithic steel bridge deck system are studied with finite element analysis. The results show that thickness of flange of U rib has relative large positive influences on rigidity, strength and stability of orthotropic monolithic steel bridge deck system. 14~18mm is the appropriate range of thickness of flange of U rib for high-speed railway steel bridges.

Study on bearing structure and joint seismic resistance of large span non-landing arch on high-speed railway station

2019 ◽  
Author(s):  
Liu Chuanping ◽  
Tianluan Liu ◽  
Jian Jia
Keyword(s):  
High Speed ◽  
Low Frequency ◽  
Large Earthquake ◽  
Scale Model ◽  
Railway Station ◽  
High Speed Railway ◽  
Long Span ◽  
Weak Component ◽  
Double Beam ◽  
Cyclic Loading Tests

<p>The main entrance of Chongqing West Railway Station adopts the non-landing compound arch with a span of 108m. In this paper, the nonlinear finite element theory is applied to analyze the bearing capacity and seismic ductility of the compound arch joints. Low frequency cyclic loading tests are performed on the 1/5 scale model. Based on the calculation and test results, a double beam structure and a section of steel truss are placed in the arch joints to bear the force of the arch. Moreover, the buckling-restrained brace (BRB) is placed in the lower part of the arch that enables most force directly transmit to the foundation of the arch. Unlike BRB’s common use as an inter-column support, it now acts as a buckling constraint support in the large earthquake. For instance, it can be yielded before the frame column to improve earthquake resistance. The research results indicate that the compound arch joint structure successfully accomplishes the seismic design goals of strong joints with weak component. Moreover, the study provides the theoretical basis and design reference for the application of BRB and long-span arch structures in high-speed railway station.</p>

Dynamic Responses of Bridge–Tunnel Overlapping Structure for High-Speed Railway Under Different Seismic Excitations

2018 ◽  
Vol 37 (1) ◽  
pp. 43-60
Author(s):  
Guangchen Sun ◽  
Jiayou Xie ◽  
Shan He ◽  
Helin Fu ◽  
Xueliang Jiang ◽  
...  
Keyword(s):  
High Speed ◽  
Dynamic Responses ◽  
Seismic Excitations ◽  
High Speed Railway

An Efficient Non-Iterative Hybrid Method for Analyzing Train–Rail–Bridge Interaction Problems

2020 ◽  
pp. 2150029
Author(s):  
Kang Shi ◽  
Xuhui He ◽  
Yunfeng Zou ◽  
Zhi Zheng
Keyword(s):  
Hybrid Method ◽  
Computational Efficiency ◽  
High Speed ◽  
Low Frequency ◽  
Coupled Analysis ◽  
Time Step ◽  
Coupling Vibration ◽  
Current Time ◽  
Railway Bridges ◽  
Frequency Coupling

The dynamic interaction problem for the train–rail–bridge (TRB) systems presents a computational challenge, especially for the analysis of large-size TRB coupling systems. To address this issue, an efficient non-iterative hybrid method (NHM) is proposed. With this method, the integrated TRB system is divided into three subsystems, i.e. the train subsystem, the rail subsystem, and the bridge subsystem. Based on the individual subsystems, a multi-step[Formula: see text] technique is adopted in which a fine time step is used to analyze the high-frequency coupling vibration for the train and rail subsystems, and a coarse time step is adopted to calculate the low-frequency coupling vibration for the rail and bridge subsystem. Additionally, Zhais explicit integral method is used to predict the displacement of the wheelsets and the rail at the current time step before using the Newmark method. The proposed method incorporates the advantages of Zhai’s explicit method and the MS technique to avoid the iteration that may be required for the train–rail coupled analysis. The simulation fidelity and computational efficiency of the proposed method are demonstrated in the analysis of two examples of typical high-speed railway bridges. It was demonstrated that the proposed method can significantly enhance the computational efficiency, while maintaining a higher precision with a larger time step in comparison with other existing methods.

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.

Analysis of Dynamic Responses of Bridge-Subgrade Transition of High-Speed Railway

2011 ◽  
Vol 90-93 ◽  
pp. 189-196 ◽  
Author(s):  
Chang Wei Yang ◽  
Jian Jing Zhang ◽  
Chuan Bin Zhu
Keyword(s):  
High Speed ◽  
Deflection Angle ◽  
Coupled System ◽  
Dynamic Responses ◽  
Practical Situation ◽  
High Speed Railway ◽  
Ballastless Track ◽  
Track Dynamics ◽  
Coupling Dynamics ◽  
Analysis Models

Referred the vehicle-track coupling dynamics theory [1] and the vertical dynamic analysis models of Bridge-Subgrade transition developed by Zhai [2] ，Wang [3] and others [4]. This article takes account of the interaction between different structural layers in the subgrade system further by using the dynamic ballastless track model and finally establishes a space dynamic numerical model of the vehicle-track-subgrade coupled system. The dynamic response of the coupled system is analyzed when the speed of the train is 350km/h and the transition is filled with graded broken stones mixed with cement of 3%. Results show that the setting forms of Bridge-Subgrade transition have little effect on the dynamic responses, so designers can choose it on account of the practical situation. Due to the location away from abutment about 5m has greater deformation; the stiffness within 5m should be designed alone. Based on the study from vehicle-track dynamics, we suggest that the maximum allowable track deflection angle is 0.9‰ and K30190Mpa within 5m behind the abutment.

scholarly journals Three Extensions of Tong and Richardson’s Algorithm for Finding the Optimal Path in Schedule-Based Railway Networks

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
J. Xie ◽  
S. C. Wong ◽  
S. M. Lo
Keyword(s):  
High Speed ◽  
Optimal Path ◽  
Low Frequency ◽  
Proper Treatment ◽  
High Speed Railway ◽  
Transit Systems ◽  
Transit Network ◽  
Transit Networks ◽  
Optimal Paths ◽  
Railway Networks

High-speed railways have been developing quickly in recent years and have become a main travel mode between cities in many countries, especially China. Studying passengers’ travel choices on high-speed railway networks can aid the design of efficient operations and schedule plans. The Tong and Richardson algorithm that is used in this model offers a promising method for finding the optimal path in a schedule-based transit network. However, three aspects of this algorithm limit its application to high-speed railway networks. First, these networks have more complicated common line problems than other transit networks. Without a proper treatment, the optimal paths cannot be found. Second, nonadditive fares are important factors in considering travel choices. Incorporating these factors increases the searching time; improvement in this area is desirable. Third, as high-speed railways have low-frequency running patterns, their passengers may prefer to wait at home or at the office instead of at the station. Thus, consideration of a waiting penalty is needed. This paper suggests three extensions to improve the treatments of these three aspects, and three examples are presented to illustrate the applications of these extensions. The improved algorithm can also be used for other transit systems.

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