Prediction of the response of suspension and cable-stayed bridge towers to wind loading

摘要

A semi-empirical method for the analysis of the response of some high-rise bridge towers to wind loading on the basis of simple wind tunnel tests on fixed sectional models is shown. The procedure operates in the framework of the linearized quasi-steady theory, and allows to predict the stable linearized mean and peak structural response. The towers considered are those made of two vertical or nearly vertical legs connected through horizontal members. If the connecting beams are stiff enough to make the whole tower behave as a beam, the well-kown theory for line-like structures can be applied. The input data, i.e. the mean values and power spectral density functions of the aerodynamic coefficients, can be drawn from wind tunnel pressure measurements on fixed sectional models. The calculation of the response needs to be done numerically. In some cases it is useful to apply a procedure based on the use of influence lines for the direct calculation of the response. The procedure is applied to the calculation of the response of a 107.50 m high suspension bridge tower, and the results are compared with those obtained by means of wind tunnel tests on an aeroelastic replica model.