Study On Dynamic Characteristics And Buf Feting Response Of Suspension Pipe Bridge

Suspension pipeline bridge is an important form of oil and gas pipeline crossing,and it is generally located between mountains and canyons.It has many applications in the mountainous terrain in southwestern China.However,it is not a mainstream road transport bridge,there is less research on wind-induced vibration of suspension pipeline bridge,and wind tunnel test data is also relatively lacking.The section width of the main girder of a suspension pipeline bridge is generally very small,and the design of the main girder is steel girder in the general,and the lateral rigidity is so small that its structural characteristics,resulting in the general,need to install additional wind resistant cable to solve its wind-induced vibration,especially buffeting problem.In this paper,we take the Menggang River suspension pipeline bridge above the river canyon in Yunnan as an example to systematically study the buffeting and wind-resistance problems of the suspension pipeline bridge.The main aspects are as follows:(1)The main features of the turbulence characteristics in the atmospheric boundary layer and the metrics are reviewed,and the common calculation formulas for turbulence intensity,turbulence integral scale and wind power spectral density function are listed.Based on the location of the suspension bridge pipe bridge in the mountainous region studied in this paper,the calculation method of the reference wind speed at the mountain bridge site is summarized.The reference wind speed of the bridge in the mountainous area is calculated by using the Menggang River suspension cable bridge as an example;(2)The design principles of the full-bridge aeroelastic model of the suspension bridge are introduced,and the similarities that should be observed in the wind tunnel test are described.The truss beam is converted into a single beam suitable for the calculation of the dynamic characteristics by means of equivalent replacement of a single beam.In the model,a full-bridge finite element model was then used to calculate the dynamic characteristics of the Menggang Suspension Pipe Bridge.In the full bridge aeroelastic model test,"U" type springs are used to connect the truss stiffened girders to simulate the stiffness of the main girder.The design principle of the "U" spring is discussed.The influence of various parameters on the modal frequency of the full bridge is analyzed and adopted.The modal test verifies that this method is a full bridge aeroelastic model design method suitable for the suspension pipeline bridge;(3)The frequency-domain calculation method of buffeting response is deduced.Under different angles of attack and different wind speeds,the buffeting response is calculated based on the date of the three-component force coefficient and flutter derivative of the measured wind tunnel.At last,in the numerical simulation calculation,a full bridge aeroelastic model test was conducted under a turbulent wind field and the model’s buffeting response data was collected.Compared with the previous numerical simulation results,the results show that the frequency domain calculation method is suitable for the buffeting response of suspension pipeline bridge.