Impact Coefficient Analysis of Long-Span Railway Cable-Stayed Bridge Based on Coupled Vehicle-Bridge Vibration

Yongle Li,Yulong Bao,Shifu Dong,Shizhong Qiang,Kejian Chen

doi:10.1155/2015/641731

Yongle Li, Yulong Bao + Show 3 more

Open Access

https://doi.org/10.1155/2015/641731

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Abstract

Compared with medium and small span bridges, very limited attention has been paid on the research of the impact coefficient of long-span railway bridges. To estimate the impact effects of long-span railway bridges subjected to moving vehicles, a real long-span railway cable-stayed bridge is regarded as the research object in this study, and a coupled model of vehicle-bridge system is established. The track irregularities are taken as the system excitation and the dynamic responses of the vehicle-bridge system are calculated. The impact effects on main girder, stayed cable, bearings, and bridge tower are discussed at various vehicle speeds. The results show that different components of the long-span railway cable-stayed bridge have different impact coefficients. Even for each part, the impact coefficient is also different at different local positions. It reveals that the impact coefficients in the actual situation may have significant differences with the related code clauses in the present design codes.

Highlights

Along with the all-round development of the railways in China, higher train speed, heavier axle load, and greater traffic density have brought out the issue of the dynamic interaction between vehicles and old long-span railway bridges
Among the crucial parameters of the bridge, the impact coefficient is commonly utilized for the performance evaluation of the long-span railway bridges
In the bridge design codes, the impact coefficient is defined as an increase factor of the static loads, which reflects the dynamic effects of the moving vehicles on bridges

Summary

Introduction

Along with the all-round development of the railways in China, higher train speed, heavier axle load, and greater traffic density have brought out the issue of the dynamic interaction between vehicles and old long-span railway bridges. Long-span railway bridges are subjected to intensive environmental loadings due to the interaction with the environment conditions [1,2,3]. In the bridge design codes, the impact coefficient is defined as an increase factor of the static loads, which reflects the dynamic effects of the moving vehicles on bridges. Matsuura studied the dynamic characteristics of high-speed railway bridges subjected to moving vehicles and indicated that the bridge resonance induced by the regular arrangement of axle load was significant [10]. Chen et al studied the static, dynamic, and fatigue condition of long-span suspension bridges on the basis of structural health monitoring system (SHM) [13, 14]. A long-span railway cable-stayed bridge is investigated in order to evaluate the impact effects of each component. The coupled vehiclebridge vibration analysis could be regarded as a theoretical method to quantify the impact response of bridges in the vibration monitoring based on field testing

Modeling of Coupled Vehicle-Bridge System and Its Verification

Analysis of Impact Coefficient for Long-Span Cable-Stayed Bridge

Conclusions

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