Wind-rain-induced vibration and control of stay cables in a cable-stayed bridge

This paper presents an analytical model for investigating wind-rain-induced vibration and control of stay cables in a cable-stayed bridge. The single-degree-of-freedom (SDOF) wind-rain excitation model developed from a sectional cable model is applied to a taut stay cable, taking into consideration the variation of mean wind speed along the stay cable and the effect of mode shapes of cable vibration. The computed results from the analytical model are then compared with the available field measurement results. After comparison, the parameter studies are performed to explore the mechanism of windrain-induced vibration of stay cables. The analytical model developed in this study can also consider cable vibration control, in which a linear viscous damper is attached to the stay cable near its anchorage. Clamped and undamped mode shapes of the stay cable and the Runge-Kutta-Fehlberg method are used to find the numerical solutions. The numerical results show that there is an optimum damping coefficient of the viscous damper to achieve the best mitigation of wind-rain-induced cable vibration. This optimum damping coefficient is almost the same as that obtained from the complex eigenvalue analysis of the stay cable with a viscous damper.