The Analysis On The Buffeting Response Spectrum Of Long-span Bridges

With the increasing of the bridge span, bridge structures are becoming much softer so that long span bridge sensitives to wind load.Bridge wind resistance will become more and more prominent.This paper mainly studies on buffeting that caused by turbulent of wind.Although the buffeting can't cause the catastrophic destroy of the bridge,the large buffeting response will affect the safety of persons and machines at the construction. Also it will affect the comfortable of persons and vehicles at the finish of the bridge. More even the large buffeting response may cause fatigue of bridge elements.Therefore it needs pay more attention to buffeting.Buffeting response spectrum is based on the Davenport's Theory and Scanlan's Theory. This method is similar to the response spectrum analysis in seismic engineering. In chapter 2, It is about the buffeting response spectrum and the accurate analysis method. In chapter 3, the accurate analysis method is simplified with the requirement of practical engineering application. A suspension bridge and a cable-stayed bridge are taken as real engineering examples to illustrate the usage of the practical method which introduced background response influence coefficients. In chapter 4,it is discussed the parameter how to affect buffeting response.The analysis indicated that wind speed,frequency, damping ratio,air operated admittance function and autoexcitation strength affect greatly the buffeting response. With the low wind speed, the background part of buffeting response holds a great proportion in all response. So we can't neglect the background part in more precise analysis about buffeing response.