Investigation On Background Wind-Load Response Of Aqueduct Bridges

On basis of existing researches on high-rise buildings and bridges, this paper uses the method of LRC,GLF (with and without wind velocity spatial correlation) and QML, to analyze the background equivalent wind load distribution and background response for the aqueduct bridges. According to practical engineering examples, this paper computed the background equivalent wind load distribution and background responses of the double-cantilever and arch aqueduct structures. The analytical results indicate as follows:1) It obtains lower background response and background equivalent wind load distribution by using Davenport's power spectrum than by using Kaimal's power spectrum. This paper suggests applying Kaimal's spectrum in the wind-resistance-calculation of aqueduct bridges, the results will be more safety.2) The LRC method gets lower background response and background equivalent wind load distribution than that of GLF (not considering wind velocity's spatial correlation) method, when the same wind power spectrum is used. The GLF method (Code method) gives the more conservative results.3) The GLF method (with wind velocity spatial correlation) gets lower backgroundresponse value than that of LRC method. So the GLF method (with wind velocity spatial correlation) may tend to un-safety.4) The background response decreases with the height increasing for the same aqueduct bridge.5) The peak factor g_B = 3.5 obtains greater background wind response than that ofg_B = 2.2. The international criterion g_B = 3.5 is suggested in this paper.