scholarly journals Vibration response of railway cable-stayed bridges under high-speed train braking loads

2020 ◽  
Vol 165 ◽  
pp. 04053
Author(s):  
Long Lu

With the increase of the running speed of high-speed trains, the longitudinal vibration of the long span railway cable-stayed bridge under train loads has increased significantly. And the probability of high-speed train braking is greater than earthquake. The excessive vibration response will affect the serviceable of the cable-stayed bridge. Fluid viscous dampers (FVDs) and elastic cables (ECs) which are widely used in seismic design of the bridge are adopted to control the longitudinal vibration response of the cable-stayed bridge induced by train braking loads. The influence of the design parameters of FVDs and ECs on the response of the bridge is studied. And the effectiveness of FVDs and ECs on mitigating the longitudinal response of the bridge is also discussed. It is found that installing FVDs and ECs between the deck and the tower is very efficient in reducing the longitudinal vibration of the railway cable-stayed bridge subjected to train braking loads, especially the longitudinal displacement of the deck and the bending moment of the tower.

2011 ◽  
Vol 255-260 ◽  
pp. 1795-1799
Author(s):  
De Shan Shan ◽  
Yuan He ◽  
Li Qiao

As the floating type cable-stayed bridge has no longitudinal constraint between the main girder and the pylon, it may cause the main girder a large longitudinal displacement and the root of tower a large longitudinal bending moment, and affect the normal use and safety of the bridge under the earthquake or the train braking. It is an important part of the design to select an appropriate vibration control scheme. Taking a long-span railway bridge for example, this paper build the finite element model and analyses the damping effect in the view of train braking, moreover, the present study also examines the dynamic behavior with focus on two parameters of damping coefficient C and damping exponent αof the viscous dampers through dynamic time-history analysis. The results show that setting viscous dampers with the reasonable parameters can reduce the vibration and the response of the bridge by train braking and have a good energy dissipation effect.


2018 ◽  
Vol 18 (04) ◽  
pp. 1850052 ◽  
Author(s):  
Long Lu ◽  
Jianzhong Li

The paper is aimed at investigating the longitudinal vibration and vibration reduction of a cable-stayed bridge under vehicular loads with emphasis on the longitudinal resonance. To investigate the phenomenon of longitudinal resonant vibration, the equivalent longitudinal excitation for the bridge deck due to moving vertical loads is approximately expressed as longitudinal loads with a sine-wave form. A formula for estimating the longitudinal resonant speed of the cable-stayed bridge is developed. A long-span cable-stayed railway bridge is considered in the case study to calculate the longitudinal response of the bridge under moving loads at different speeds. The numerical results indicate that the longitudinal resonance for the cable-stayed bridge occurs when the speeds of the moving loads approach the resonant speed predicted by the analytical formula. A fluid viscous damper (FVD) is employed to reduce the longitudinal vibration of the bridge under moving loads. The results show that the longitudinal resonant responses of the cable-stayed bridge can be effectively mitigated by the FVD adopted.


Author(s):  
Meera Patel ◽  
Bhanu Pratap

An adaptive observer-based controller design for the nonlinear model of a high-speed train is demonstrated in this paper. A high-speed train belongs to the class of multivariable and coupled dynamic system with a higher degree of nonlinearities and uncertainties. The radial basis function neural network is used for the approximation of these nonlinearities and uncertainties. Using this approximation, an adaptive neuro-observer is designed for the estimation of the unavailable states of the high-speed train for measurement. Using one-to-one nonlinear mapping, the high-speed train plant and the adaptive neuro-observer are remodelled in a pure feedback form without any constraints on states. On the basis of the adaptive neuro-observer, an adaptive dynamic surface controller is designed for the high-speed train system. The upper bounds of the actual controller gains of the high-speed train need not be known whereas the lower and upper bounds of the virtual controller gain require prior knowledge. The tuning of the design parameters has been done online in the proposed observer/controller. The closed-loop stability and convergence have been analysed through a formal proof based on the Lyapunov approach. The enhanced performance of the high-speed train with the proposed controller is compared with the backstepping control approach and demonstrated using simulation studies.


2014 ◽  
Vol 73 (1-4) ◽  
pp. 251-265 ◽  
Author(s):  
J. Zhang ◽  
G. F. Ding ◽  
Y. S. Zhou ◽  
J. Jiang ◽  
X. Ying ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Xiaopei Cai ◽  
Wanli Liu ◽  
Kaize Xie ◽  
Wenjun Zhu ◽  
Xiyuan Tan ◽  
...  

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.


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