Previous studies have indicated that the across-wind dynamic responses of super-tall buildings are usually larger than the along-wind ones. With the increase of heights, the acrosswind dynamic response of super-tall buildings has been a problem of great concern. In this paper, 15typical tall building models are tested with high-frequency force balance technique in a wind tunnel to obtain the first-mode generalized across-wind dynamic forces. New formulas for the power spectra of the across-wind dynamic forces, the coefficients of base moment and shear force are then derived. Parametric analyses of the effects of factors on the across-wind loads of the buildings are performed. Besides, a SDOF aeroelastic model of a square tall building with an aspect ratio of 6 is selected from the above buildings and is tested to investigate its across-wind dynamic response and aerodynamic damping characteristics. The power spectrum of the across-wind force of the square building is employed to compute its across-wind dynamic responses with and without considering the effect of the aerodynamic damping. The computed responses are then compared with the corresponding responses from the aeroelastic model test to verify the present formulas of the across-wind loads of uildings.

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.

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.

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.