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Influence of Inhomogeneous Wind Fields on the Aerostatic Stability of a Cable-Stayed Pedestrian Bridge without Backstays: Experiments and Numerical Simulations

Authors: Yanru Wu, Qing Sun

Abstract:

Sightseeing glass bridges located in steep valley area are being built on a large scale owing to the development of tourism. Consequently, their aerostatic stability is seriously affected by the wind field characteristics created by strong wind and special terrain, such as wind speed and wind attack angle. For instance, a cable-stayed pedestrian bridge without backstays comprised of a 60-m cantilever girder and the glass bridge deck is located in an abrupt valley, acting as a viewing platform. The bridge’s nonlinear aerostatic stability was analyzed by the segmental model test and numerical simulation in this paper. Based on aerostatic coefficients of the main girder measured in wind tunnel tests, nonlinear influences caused by the structure and aerostatic load, inhomogeneous distribution of torsion angle along the bridge axis, and the influence of initial attack angle were analyzed by using the incremental double iteration method. The results show that the aerostatic response varying with speed shows an obvious nonlinearity, and the aerostatic instability mode is of the characteristic of space deformation of bending-twisting coupling mode. The vertical and torsional deformation of the main girder is larger than its lateral deformation, with the wind speed approaching the critical wind speed. The flow of negative attack angle will reduce the bridges’ critical stability wind speed, but the influence of the negative attack angle on the aerostatic stability is more significant than that of the positive attack angle. The critical wind speeds of torsional divergence and lateral buckling are both larger than 200 m/s; namely, the bridge will not occur aerostatic instability under the action of various wind attack angles.

Keywords: Aerostatic nonlinearity, cable-stayed pedestrian bridge, numerical simulation, nonlinear aerostatic stability.

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References:


[1] M. Xu, W. W. Guo, H. Xia, et al. Nonlinear aerostatic stability analysis of Hutong cable-stayed rail-cum-road bridge. J. Wind and Structures, 2016, 23(6): 485-503.
[2] W. M. Zhang, K. R. Qian, L. Wang, et al. Aerostatic instability mode analysis of three-tower suspension bridges via strain energy and dynamic characteristics. J. Wind and Structures, 2019, 3(29):163-175.
[3] Q. Zhou, H. L. Liao, T. Wang. Numerical study on aerostatic instability modes of the double-main-span suspensions bridges. J. Shock and Vibration, 2018(PT.1): 7458521-7458529.
[4] F. H. Dong, J. Cheng. A new method for estimation of aerostatic stability safety factors of cable-stayed bridges. J. Proceedings of the Institution of Civil Engineers-Structures and Buildings, 2019, 172(1): 17-29.
[5] American society of civil engineers. ASCE/SEI 7-10, New York, 2010.
[6] Wind-resistent Design Specification for Highway Bridges. JTG/T 3360-01-2018, China. (In Chinese)
[7] P. Hu, Y. Han, G. Xu, et al. “Numerical simulation of wind fields at the bridge site in mountain-gorge terrain considering an updated curved boundary transition section.” J. Aerosp. Eng. 2018, 31 (3): 04018008.
[8] Z. T. Zhang, Y. J. Ge, and Z. Q. Chen. “On the aerostatic divergence of suspension bridges: A cable-length-based criterion for the stiffness degradation.” J. Fluids Struct. 2015, 52 (Jan): 118–129.
[9] P. Hu, Y. Han, G. J. Xu, et al. Effects of inhomogeneous wind fields on the aerostatic stability of a long-span cable-stayed bridge located in a mountain-gorge terrain. J. Journal of Aerospace Engineering, 2020, 33(3):04020006.
[10] J. Y. Zhang, M. J. Zhang, Y. L. Li, et al. Comparison of wind characteristics at different heights of deep-cut canyon based on field measurement. Advances in Struct. Engi. 2020, 23(2), 219-233.
[11] Z. Q. Chen, Bridge Wind Engineering. China Communications Press. China, Beijing, 2005. (In Chinese)