Experimental Investigation On The Aerostatic Characteristics Of Icing Suspension Pipeline Bridge

Along with the development of oil and gas pipeline transportation in China,pipeline suspension bridge is widely used in pipeline crossing project due to its advantages of large span,beautiful appearance and good economy.Compared with highway suspension bridges,because of its narrow,flexible,light and blunt features,the problem of wind resistance stability of pipeline suspension bridge is more prominent.Most of the areas of the pipeline suspension bridge in China are frequently occurring in the cold rain weather.The structure of the pipeline suspension bridge changes its structure,which may further reduce the wind stability.In order to study the static aerodynamic characteristics of the pipeline suspension bridge after icing,the ice cover form of the pipeline suspension bridge,the aerodynamic characteristics of the typical double tube section and the aerodynamic characteristics after icing are studied in this paper.The main work and conclusion are as follows:(1)In the climate laboratory,the effects of different pipe sizes,different installation methods,different sections and rainfall on the ice cover of the suspension bridge were studied,including the radial ice and ice edge.The results show that there are three kinds of crescent shaped,hump shaped and fan-shaped pipes,which increase with ice precipitation.The length of the ice edge is directly related to the precipitation and the diameter of the tube,but the diameter and other dimensions are basically the same.The icing of truss and grate plate is mainly on the face of rain.After ice coating,it is equivalent to thickening and widening the original component.(2)Taking two typical pipeline suspension bridge sections as an example,the influence of different structure parameters,such as perforation rate,different pipe spacing and pipe diameter,on the static three force coefficient of structure,is studied to provide guidance for wind resistance design of suspension pipeline bridge.The results show that the perforation rate of the grate plate has an obvious influence on the static three force coefficient,and the effect of lift and lift moment must be considered in the design,and the perforation rate of the grate plate can be increased as much as possible.The increase of pipeline spacing,drag coefficient and lifting moment coefficient increase obviously,and lift coefficient is relatively small.The lift coefficient decreases with the increase of pipe diameter,drag coefficient and lift torque coefficient.In the range of Reynolds number of 1.7×10~5~3.0×10~6,the Reynolds number effect exists in the static three force coefficient of the pipe bridge,and the lift coefficient and the lift torque coefficient vary obviously with the Reynolds number.(3)Through the analysis of the ice cover test of the suspension pipeline bridge,the ice cover model of three kinds of crescent shaped,D and fan shaped pipes and other components of the suspension pipe bridge are summarized.The influence of icing on the static three component coefficient of suspension bridge is studied by wind tunnel test.The results show that when the structure is iced,the static three component coefficient of the model will be greatly increased,which seriously endangers the safety of the structure.However,the resistance coefficient is less sensitive to ice shape.With the increase of ice thickness,the drag coefficient increases.However,the lift coefficient and the lifting moment coefficient are more sensitive to ice shape,and the D icing is the most dangerous.