Rain–wind-induced vibration of cables in cable-stayed bridges is presently a worldwide problem of great concern. Because it is sensitively influenced by many parameters, this peculiar phenomenon is difficult to be replicated in laboratory conditions; its mechanism has not been well explained yet. In this paper, the phenomenon of rain–wind-induced vibration of a cable model is successfully reproduced under actual rain conditions in a wind tunnel. The effects of several main factors, including the inclination angle, frequency and damping of the cable as well as the wind yaw angle, etc. on the characteristics of rain–wind-induced vibration are investigated in detail in the test. The countermeasures of double-spiral wires and dampers for the mitigation of the vibration are also experimentally studied. The results show that the size and twine direction and the pitch of the spiral wires twined on the surface of cables have great effects on the mitigation efficiency of rain–wind-induced vibration of cables.

Flutter derivatives and aerodynamic admittances provide basis of predicting the critical wind speed in flutter and buffeting analysis of long-span cable-supported bridges. In this paper, one popular stochastic system identification technique, covariancedriven stochastic subspace identification (SSI in short), is first presented for estimation of the flutter derivatives and aerodynamic admittances of bridge decks from their random responses in turbulent flow. Numerical simulations of an ideal thin plate are adopted to extract these aerodynamic parameters to evaluate the applicability of the present method. Then wind tunnel tests of a streamlined thin plate model and a P type blunt bridge section model were conducted in turbulent flow and the flutter derivatives and aerodynamic admittances are determined by the SSI technique. The identified aerodynamic parameters are compared with the theoretical ones and the results indicate the applicability of the current method.

With the rapid increase of bridge spans, research on controlling wind-induced vibration of long-span bridges has been a problem of great concern. In view of the fact that the vibration frequencies and damping of long-span bridges vary with wind speed, and the variation characteristics could not be accurately known even if through wind tunnel experiments, a concept of semi-active (SA) control of ind-induced vibration of long-span bridges is put forward in this paper. A new SA lever-type TMD with an adjustable frequency and the corresponding control strategy are primarily developed. A case study of the Yichang bridge, a suspension bridge with a main span of 960 m, shows that the SA lever-type TMD device is much superior to passive TMD in control efficiency and robustness.

For practical purpose, buffeting response of cable-stayed bridges to wind excitation is usually analytically determined by single-mode-based method, and the resultant response is written as the composition of the resonant component and the background component by the square root of sum squares (SRSS) method. The background component is sometimes neglected for simplifying computations. In the present paper, numerical computations on four representative cable-stayed bridges in China indicate that the background component usually has a significant contribution to the buffeting response of long-span cable-stayed bridges. Parametric studies on the effects of structural parameters on the buffeting background components for these four bridges are also performed. A simplified method introduced in literatures for estimation of the background component of buffeting response is then briefly discussed. Finally an approximate method for estimating the first vertical bending modebuffeting response of cable-stayed bridges is proposed.

A control strategy named Sinusoidal Reference Strategy is developed for adaptive feedforward control of wind-induced vibration of super-tall buildings. In this approach a high-frequency sinusoidal signal is adopted as the reference signal for the strategy. Some shortcomings of the conventional adaptive feedforward control method can be overcome. A MDOF general building aeroelastic model with a square cross-section was tested in a wind tunnel. The testing results show that the present strategy can reduce vibration effectively, and can adapt to wind-induced vibration control of tall buildings with dynamic uncertainties and modeling errors.