scholarly journals Train-Bridge Dynamic Behaviour of Long-Span Asymmetrical-Stiffness Cable-Stayed Bridge

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Yuexing Wu ◽  
Jianting Zhou ◽  
Jinquan Zhang ◽  
Qiang Wen ◽  
Xuan Li
Keyword(s):  
Dynamic Behaviour ◽  
Model Updating ◽  
Ride Comfort ◽  
Observation Point ◽  
Main Beam ◽  
Train Track ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Significant Difference ◽  
Track Bridge

Long-span cable-stayed bridge (LCB) with unequal-height towers is being designed and constructed in metro lines due to its better adaptability to environment and terrain conditions compared to traditional cable-stayed bridge with equal-height towers. However, the asymmetrical arrangement of towers leads to obvious nonuniformity of the structural stiffness along the longitudinal direction, which intensifies the wheel-rail coupled vibration behaviour, and affects the running safety of operating trains and ride comfort. Therefore, train-bridge dynamic behaviour of long-span asymmetrical-stiffness cable-stayed bridge is deeply investigated in this work. Primarily, considering the comprehensive index of frequency difference and modal assurance criterion (MAC), a nonlinear model updating technique (NMUT) based on penalty function theory is proposed, which can be used to optimize the bridge numerical model. Secondly, on the basis of the train-track-bridge dynamic interaction theory (TDIT), a train-track-bridge coupled dynamic model (TCDM) is established. Finally, a LCB with unequal-height towers is applied as a case to illustrate the influence of asymmetrical stiffness on the train-track-bridge dynamic characteristics. Results show that the proposed NMUT is efficacious and practical. For the LCB with unequal-height towers, a significant difference between the bridge vibration at low tower location and that at high tower location appears. The vertical displacement difference of the main beam on both sides of the bridge increases with the distance from the observation point to the bridge tower increasing. The variation of acceleration difference on both sides of the bridge is influenced by the speed of the train and the position of the observation point simultaneously. In general, vibrations of the main beam at low tower location are larger than those at high tower location.

scholarly journals Layout Optimization of Rail Expansion Joint on Long-Span Cable-Stayed Bridge for High-Speed Railway

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Xiaopei Cai ◽  
Wanli Liu ◽  
Kaize Xie ◽  
Wenjun Zhu ◽  
Xiyuan Tan ◽  
...  
Keyword(s):  
High Speed ◽  
Field Tests ◽  
Element Model ◽  
Longitudinal Force ◽  
Main Beam ◽  
Expansion Joint ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Small Resistance ◽  
Set Up

Continuous welded rail (CWR) has been widely applied to the Chinese high-speed railways. It is interesting to reduce the effect of rail longitudinal force on the long-span cable-stayed bridges. Taking the pile-soil interaction into account, the finite element model of CWR on the long-span cable-stayed bridge is established based on the bridge-track interaction theory. The rail longitudinal force can be reduced and the track stability can be improved significantly by installing Rail Expansion Joint (REJ). The layout scheme of REJ plays a controlling role on designing CWR on bridges. Results show that the unidirectional REJ should be laid on both ends of the long-span cable-stayed bridge. Switch rails of REJ are set up on the main beam, stock rails are laid on the simply supported beams and crossing over beam joints, and several-meter long small resistance fasteners need to be laid on the sides of stock rails to reduce the fixed pier longitudinal force near the main beam. The range of REJ laid on cable-stayed bridge is mainly determined by temperature, rail breaking, and seismic condition; the bending and braking loads have little influence on it. Multiple field tests are carried out to prove the validity of the numerical model and the design methodology.

scholarly journals High-Speed Train-Track-Bridge Dynamic Interaction considering Wheel-Rail Contact Nonlinearity due to Wheel Hollow Wear

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Chao Chang ◽  
Liang Ling ◽  
Zhaoling Han ◽  
Kaiyun Wang ◽  
Wanming Zhai
Keyword(s):  
High Speed ◽  
Synthesis Method ◽  
Dynamic Interaction ◽  
High Speed Train ◽  
Train Track ◽  
High Speed Railway ◽  
Long Span ◽  
Continuous Girder Bridge ◽  
Girder Bridge ◽  
Track Bridge

Wheel hollow wear is a common form of wheel-surface damage in high-speed trains, which is of great concern and a potential threat to the service performance and safety of the high-speed railway system. At the same time, rail corridors in high-speed railways are extensively straightened through the addition of bridges. However, only few studies paid attention to the influence of wheel-profile wear on the train-track-bridge dynamic interaction. This paper reports a study of the high-speed train-track-bridge dynamic interactions under new and hollow worn wheel profiles. A nonlinear rigid-flexible coupled model of a Chinese high-speed train travelling on nonballasted tracks supported by a long-span continuous girder bridge is formulated. This modelling is based on the train-track-bridge interaction theory, the wheel-rail nonelliptical multipoint contact theory, and the modified Craig–Bampton modal synthesis method. The effects of wheel-rail nonlinearity caused by the wheel hollow wear are fully considered. The proposed model is applied to predict the vertical and lateral dynamic responses of the high-speed train-track-bridge system under new and worn wheel profiles, in which a high-speed train passing through a long-span continuous girder bridge at a speed of 350 km/h is considered. The numerical results show that the wheel hollow wear changes the geometric parameters of the wheel-rail contact and then deteriorates the train-track-bridge interactions. The worn wheels can increase the vibration response of the high-speed railway bridges.

scholarly journals Seismic Response Mitigation of a Long-Span Tower Bridge with Two Types of Constraint System

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Li Xu ◽  
Qingfei Gao ◽  
Junhao Zheng ◽  
Chuanhui Ding ◽  
Kang Liu
Keyword(s):  
Element Model ◽  
Main Beam ◽  
Seismic Load ◽  
Viscous Damper ◽  
Viscous Dampers ◽  
Damping Effect ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Drift Frequency ◽  
Nonlinear Finite Element Model

The stress of the main tower of a cable-stayed bridge depends on the connection type between the tower and deck. In order to study the most suitable longitudinal damping mode for a long-span cable-stayed bridge. In this article, a nonlinear finite element model is established based on a large span concrete cable-stayed bridge with a main span of 680 m. Without considering the influence of the transverse constraint, the damping effect of the elastic connection device and the viscous damper is simulated when the longitudinal seismic load is input. The results show that the stiffness of the main beam is increased by installing the elastic connection device, so the longitudinal drift frequency of the main beam is increased, but the stiffness of the structure is not changed by installing the viscous damper. Both viscous dampers and elastic connection structures can reduce the longitudinal displacement of the beam end, but viscous dampers are more favorable for the stress of the main tower. In terms of damping effect, viscous dampers are more suitable for long-span cable-stayed bridges, but, in terms of economy and parameter control, elastic connection devices have more advantages.

Running safety evaluation of high-speed train subject to the impact of floating ice collision on bridge piers

2021 ◽  
pp. 095440972110100
Author(s):  
Penghao Li ◽  
Zhonglong Li ◽  
Zhaoling Han ◽  
Shengyang Zhu ◽  
Wanming Zhai ◽  
...  
Keyword(s):  
High Speed ◽  
Ride Comfort ◽  
Dynamic Responses ◽  
Impact Loads ◽  
High Speed Train ◽  
Train Track ◽  
Railway Bridges ◽  
Running Safety ◽  
Track Bridge ◽  
The Impact

In Northeast China and the areas along Sichuan-Tibet railway, collision between floating ice and piers of railway bridges seriously threatens the train operation safety. The safety of high-speed train running on the bridge subject to the impact of floating ice collision is rarely assessed considering the spatial interaction of the train-track-bridge-ice system. To evaluate the running safety and ride comfort of trains and the structural stability of railway bridges under the collision between floating ices and piers, a train-track-bridge (TTB) dynamic interaction model considering the impact of floating ice is established. Using the refined finite element model, the collision process of floating ice on bridge pier is simulated, and the impact loads are employed as the excitation input of the TTB dynamics model. Taking a 5 × 32 m simply-supported bridges as a case study, the influence of bridge structural parameters on the floating ice collision system is investigated, and then the dynamic responses of the TTB system induced by the floating ice impact loads are analyzed in detail. Finally, the effect of the ice impact loads on the running safety of the high-speed train is revealed. Results show that under the floating ice impact loads, the angle of the pier sharp-nose (APSN) and lateral stiffness of foundations are the key parameters that influence the dynamic responses of the bridge, and an improperly small lateral stiffness of foundation would lead to an instability of bridge structure. The influence of ice impact loads on the dynamic responses of the train is remarkable. The lateral vibration acceleration, derailment factor and lateral wheel rail force caused by the ice impact loads are all greater than those caused by the track irregularity, while the wheel unloading rate is slightly smaller. In addition, the running speed of train is also closely related to the running safety and ride comfort when the collision occurs. When the train speed exceeds 400 km/h, the train passing through the bridge would have the possibility of derailment.

Seismic Response Analysis of Long Span Cable-Stayed Bridge by Response Spectrum Method

2012 ◽  
Vol 204-208 ◽  
pp. 1992-1996 ◽  
Author(s):  
Min Chao Jin ◽  
Bao Fu Wang ◽  
Zhong Ren Feng ◽  
Xiong Jiang Wang
Keyword(s):  
Response Spectrum ◽  
Vertical Component ◽  
Vertical Direction ◽  
Longitudinal Direction ◽  
Response Analysis ◽  
Response Spectrum Method ◽  
Cable Stayed Bridge ◽  
Spectrum Method ◽  
Long Span ◽  
Significant Difference

Based on response spectrum method, the seismic behavior of a long span cable-stayed bridge is investigated through three dimensional finite element model established by ANSYS. By calculating the cumulative effective mass factors of the bridge, the minimum number of modes used for modal superposition analysis is obtained. Design acceleration response spectrums under two probabilities are used in the analysis. The response spectrums are input in the bridge longitudinal direction, vertical direction, transverse direction and combined horizontal and vertical directions. Displacements and internal forces results show that vertical component of the ground motion greatly influences the response of the bridge and there is significant difference between the results of the two probabilities.

Influences of Concrete Creep and Temperature Deformation on Vehilce Travelling across Bridge

2014 ◽  
Vol 556-562 ◽  
pp. 655-658 ◽  
Author(s):  
Xiao Ping Wang
Keyword(s):  
High Speed ◽  
Concrete Bridges ◽  
Temperature Deformation ◽  
Train Track ◽  
Concrete Creep ◽  
Coupling Vibration ◽  
Long Span ◽  
High Speed Trains ◽  
Track Irregularity ◽  
Track Bridge

When long-span pre-stressed concrete bridges are subjected to concrete creep and temperature load , bridge deck deformation will be aroused. Then the additional track irregularity will be generated. It brings about the result that the dynamic response of train-track-bridge system will be influenced. In this paper, with the train-track-bridge coupling vibration theory, a (90+180+90) m continuous beam-arch combination bridge located on a certain passenger line is analysised comparatively, by considering the effect of concrete creep and temperature deformation. The results show that, the track irregularity caused by the concrete creep and temperature deformation influence the wheel unloading rate and the vertical accelararion of the train so obviously with the speed increasing. It can be concluded that the track irregularity need to be considered, especially for high-speed trains.

A real-time co-simulation solution for train–track–bridge interaction

2020 ◽  
pp. 107754632094663
Author(s):  
Wei Gong ◽  
Zhihui Zhu ◽  
Kun Wang ◽  
Weichao Yang ◽  
Yu Bai ◽  
...  
Keyword(s):  
Real Time ◽  
Large Time ◽  
Measurement Data ◽  
Dynamic Responses ◽  
Strong Wind ◽  
Train Track ◽  
Time Step ◽  
Cable Stayed Bridge ◽  
Large Time Step ◽  
Track Bridge

This study develops a real-time co-simulation solution that combines ANSYS and MATLAB for investigating of the train–track–bridge dynamic interactions, with the aim of providing an effective and robust method for analyzing and assessing the dynamic responses of running train and bridge, considering their complex nonlinear behaviors under extreme excitations such as earthquake and strong wind. The train–track–bridge coupled system consists of the train subsystem, the track subsystem, and the bridge subsystem. With the adoption of a previously developed efficient multi-time-step method, the train subsystem and the track subsystem are analyzed in MATLAB with a small time-step, whereas the bridge subsystem is analyzed in ANSYS using a large time-step. At each large time-step, the train–track subsystem in MATLAB and the bridge subsystem in ANSYS are coupled by communication of the track reaction forces calculated in MATLAB and the dynamic responses at the track–bridge connecting points calculated in ANSYS. The co-simulation procedure is validated through a comparison of the numerical results from computer coding developed by the authors and the measurement data of a cable-stayed bridge. To demonstrate the effectiveness and robustness of the proposed solution, the responses of a train passing through a cable-stayed bridge under earthquake excitation are analyzed, with consideration of the geometrical nonlinearity of the bridge, using the co-simulation solution.

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