Wind-Resistant Cable Design and Experimental Study of Long-Span Natural Gas Pipeline Suspension Crossing

Abstract

A suspension bridge for a natural gas pipeline crossing has a small width-span ratio and is characterized by low damping and low stiffness. To improve the structure’s resistance to wind loads, it is necessary to establish a cable system. Given the steep and rugged terrain of the project site, a wind-resistant system incorporating both parallel wind cables and conjugate cables was designed, with the angle between the wind cables and the horizontal plane reduced to 1.2°. Additionally, an effective calculation method was developed to accurately determine the spatial configuration of the wind-resistant cable system. The wind resistance and safety of the connection structure were validated through a 1∶25 scaled aeroelastic model test. The results from tests in both uniform and turbulent flow fields show that under wind attack angles of 0° and 3°, the flutter stability requirements were met, and no discernible vortex-induced vibration was detected within the tested range. The maximum vertical displacement response occurred at the quarter-span position, while the maximum lateral and torsional displacement response were observed at the midspan. Finally, based on the test results, the impact of aerodynamic admittance functions on the frequency-domain buffeting response of the bridge was analyzed. Overall, the test and analysis results indicate that the bridge structure meets the operational requirements of the natural gas pipeline.