Study On Coupling Effect Of Temperature And Atmosphere Wind In Steel Plate Composite Girder Bridge

Steel plate composite bridge has been widely used in bridge construction because of its advantages of fast completion,simple structure and light weight.The coupling effect of temperature and wind load is the main factors to control the design of steel plate composite bridge.On the one hand,the small cross-section area and low rigidity of steel plate composite girder bridge,the bridge alignment changes greatly under wind load and temperature,especially in the construction stage of steel plate composite beam bridge.With the popularity of steel plate composite beam bridge,high pier steel plate composite beam bridge is more and more common.For high pier steel plate composite beam bridge,because of the lengthening of construction period,the probability of meeting extreme climate conditions increases again;On the other hand,the wind resistance code of bridges is considered according to the whole wind direction,but as a structure with large gap in vertical and horizontal dimensions,it is obviously unreasonable to study wind load without distinguishing wind direction.This paper takes the 3 of the No × 50 m steel plate composite beam bridge is the main research object.Aiming at the unfavorable climate environment that the bridge may encounter during the construction of the bridge,the coupling effect of temperature and wind load of the steel plate composite beam bridge is studied.The main research contents and achievements are as follows:(1)Through sorting out the data obtained from the observation in the wood base area under different wind speed and wind direction,according to the calculation formula of the joint distribution theory of wind speed and wind direction,the least square method is used to estimate the parameters,and the wind speed probability function of different wind directions is obtained.The basic wind speed of 10-year return period and 100 year return period of different wind direction and full wind direction is calculated,The correctness of the wind speed probability function is verified by comparing the basic wind speed calculated by the full wind direction with the basic wind speed given in the specification.The analysis shows that the basic wind speed in different wind directions in the same area is different,and the basic wind speed calculated without considering the wind direction tends to be conservative.(2)Considering the influence of terrain and height on wind speed,the design reference wind speed is obtained based on the basic wind speed calculated;The finite element model is established by FLUENT software,and the wind load and static force coefficient of the composite beam bridge under different wind directions are calculated;Finally,considering the wind direction and wind speed,the most unfavorable wind direction of the main bridge of the basin Kete 2 bridge is WNW wind direction and the worst wind attack angle is 10 ° Wind attack angle.(3)The model of Midas is established.The linear changes of the steel plate composite girder bridge under the single action of temperature and wind load are analyzed by the finite element model.The change law of the bridge alignment is compared and analyzed;Considering the influence of wind speed on temperature,the linear changes of main girder in different construction stages are analyzed under the coupling effect of temperature wind load;Finally,the maximum displacement of the vertical displacement of the bridge under different conditions is compared,and the most unfavorable condition is obtained under the coupling action of temperature gradient and wind load in the stage of single beam frame installation...