Research Of Wind Characteristic And Static Wind Respond Of The Long-span Bridge In Mountain Areas

As the western transportation construction develops, more and more large projects of large-span bridge are launched in the mountain valley terrain, which puts forward a new challenge to wind-resistent of bridge. Although, many scholars conducted a series of studies on mountain wind-resistent at home and abroad, researches do not go far enough so that many problems exit: lack of reference material, a certain deviation between wind characteristic parameters specified by existing criterion of wind-resistent design and actual parameters existing, guiding wind-resistent of bridge design and construction according to it completely is inevitable impractical. Therefore, wind-resistent of large-span bridge in the mountain valley terrain has become the difficult problem urgently to be solved in the area of wind engineering of bridge, research on it is of far-reaching significance. Based on Aizhai Bridge of Hunan province as the research background, related research on winds characteristics of bridge sites of the mountain valley terrain and static response of large-span suspension bridge is conducted in this paper.This paper mainly carried out the following efforts:1,A kind of wind environment field observation system with the pattern of high altitude suspension cable hanging has been presented innovatively and applied in Aizhai Bridge. This system is no longer restricted by special terrain, suitable for wind speed data acquisition of engineering construction in the mountain valley terrain, and can get accurate wind characteristics of bridge sites, especially middle position of bridge axis, which provide a new method for wind characteristics observing in the mountain valley terrain.2,According to the measured data, MATLAB programs are compiled, wind characteristics in the mountain valley terrain are analyzed and researched, and the average wind speed, fluctuating wind speed, wind direction and other parameters to Aizhai bridge are obtained. 3,Separately calculated the average maximum wind velocity of 10 minutes in nearly three years and data of Jishou weather station, by using theory of small samples and Fisher-Tippett Type-I distributions, basic wind velocity of bridge design and other design parameters to Aizhai Bridge are obtained, and the calculated results are compared.4,Taking the Aizhai Bridge as an example and using ANSYS software, a finite element model for the whole bridge was established, which analyzed the dynamical property of the bridge; On the basis of the existing model, applied the measured wind load, calculated static response of bridge, analyzed the situation of being forced of bridge; Based on the modal analysis results and wind tunnel test parameters, analyzed the linear static stability and tested the static stability of the bridge.