Dynamic performance of existing high-speed railway bridges under resonant conditions retrofitted with fluid viscous dampers

The results of experimental and theoritical investigations of railway bridges have shown the significant dynamic responses exceeding that anticipated on certain railway bridges, such as a resonance phenomenon who have a great effect in the bridge. Alternatively , the use of structural control systems devices might be a very promising solution to attenuate undesirable vibration. The aim of this study, first, is to investigate the posibility of reducing the acceleration in an acceptable level by using fluid viscous dampers. The bridge-damper system is described by a single-degree-of-freedom model. The ,dampers are connected between the bottom surface of the bridge deck and the abutment, Finallay a linearisation model and a comparative study in order to investigate the effect of the nonlinearite of the device in the dynamic response of the system.

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Probability-based evaluation of the effect of fluid viscous dampers on a high-speed railway bridge

Structure and Infrastructure Engineering ◽

10.1080/15732479.2020.1832537 ◽

2020 ◽

pp. 1-13

Author(s):

Sarah Tell ◽

John Leander ◽

Andreas Andersson ◽

Mahir Ülker-Kaustell

Keyword(s):

High Speed ◽

Railway Bridge ◽

Viscous Dampers ◽

High Speed Railway ◽

Fluid Viscous Dampers

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Application of viscoelastic dampers for reducing dynamic response of high-speed railway bridges

International Review of Applied Sciences and Engineering ◽

10.1556/1848.2020.20004 ◽

2020 ◽

Vol 11 (2) ◽

pp. 95-106

Author(s):

Mohamed Tahiri ◽

Abdellatif Khamlichi ◽

Mohammed Bezzazi

Keyword(s):

High Speed ◽

Contact Point ◽

Dynamic Performance ◽

Orientation Angle ◽

Concrete Bridges ◽

Bottom Surface ◽

Vertical Acceleration ◽

High Speed Railway ◽

Railway Bridges ◽

Viscoelastic Dampers

AbstractDue to the extensive development of high-speed railway lines which are operating at increasing velocities, the dynamic performance of railway bridges has become an important issue of scientific research. The aim of this study is to investigate the possibility of reducing the vertical acceleration and displacement of pre-stressed reinforced concrete bridges beams by using passive nonlinear viscoelastic dampers to retrofit them. The proposed solution is based on connecting the dampers directly to the abutments and the bottom surface of the bridge deck with an eccentricity between the neutral axis of the bridge and the contact point of the viscoelastic dampers. First, the dampers are modeled through the concept of linearized fractional derivatives to obtain energetic equivalent linear viscoelastic dampers. Optimization of the configuration of these dampers was performed then as function of the orientation angle and the eccentricity. Considering two bridges having different length that were studied in the literature with other systems of damping, it was found that the best orientation angle of dampers is close to 60°. It was found also that, in order to satisfy Eurocode 1 requirements, the total equivalent damping coefficient for the actual damping system is less than half of that required for systems using auxiliary beam to fix dampers, which indicates higher efficiency of the proposed solution.

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Dynamic Performance Analysis of a High-Speed Railway Bridge Under Train Actions Using Operational Modal Parameters

International Journal of Structural Stability and Dynamics ◽

10.1142/s0219455421400071 ◽

2021 ◽

pp. 2140007

Author(s):

Xiao-Mei Yang ◽

Chun-Xu Qu ◽

Ting-Hua Yi ◽

Hong-Nan Li ◽

Hua Liu

Keyword(s):

Modal Analysis ◽

High Speed ◽

Dynamic Performance ◽

Modal Parameters ◽

Variational Mode Decomposition ◽

Railway Bridge ◽

High Speed Railway ◽

Railway Bridges ◽

Mode Decomposition ◽

Coupling Dynamic

For high-speed railway bridges in operation, it is necessary to reveal the coupling dynamic performance of train–bridge systems in order to avoid extreme vibrations, which are not conducive to bridge safety. With the opening of long-span heavy-haul and complex-type bridges to traffic, the train–bridge interaction can hardly be explained by a mature and unified theory. Notably, field testing and monitoring analysis have become popular in tracking the dynamic performance of train–bridge systems. The vibration of railway bridges depends on the train-track configuration and the inherent characteristics of bridges. The inherent characteristics of bridges, which are reflected by the modal parameters, are extracted via operational modal analysis in this paper. In addition, the modal characteristics of bridges while the train is passing through are also investigated to explain the coupling dynamic effect with the help of the train configuration. Considering that the measured vibration responses are seriously polluted by non-white noise or excitation, the variational mode decomposition (VMD) technique is developed to extract the state-driven vibrations for modal analysis. Since VMD is a univariate technique that hardly ensures that the weak component can be obtained from each measuring channel, the multi-channel variational mode decomposition (MVDM) technique is extended in this paper. The field monitoring data of a high-speed railway bridge are taken for modal identification and vibration analysis. The results show that the weak structural modes can be tracked, even though the forced vibrations due to the passage of regularly spaced axles are dominant. In addition, the dynamic effects in train-induced vertical vibrations of bridges are closely related to the train speed, heavy axle loads and the span length.

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