Impacts of the wind-cable system on dynamic characteristics of the pipeline suspension bridge

Rules of natural vibration and vibration shapes of a long-span suspension pipeline bridge and effects of parameters of the wind-cable system on its natural vibration characteristic were studied, in order to provide references for wind-resistant design. A simulation model of the long-span pipeline suspension bridge was established based on the FE software MIDAS/Civil. Impacts of the angle between layout plane and horizontal plane, the tensioning force of wind-cable, the rise-span ratio of wind-cable, the arrangement form of stay cables and stable cables on dynamic characteristics of the bridge were analyzed. Results indicate that the angle between layout plane and horizontal plane has a great influence on frequency of both lateral and vertical bending vibration mode. The suitable angle lies between 0~30°. As the tensioning force of wind-cable increases, the lateral and vertical bending stiffness also increases. The design for the wind cable should contain a definite safety store which is generally taken as 1.5~2.0. Under a constant tensioning force of wind-cable, when the rise-span ratio of wind-cable is less than 1/10, the force has great influences on the anti-symmetric lateral bending vibration mode of the structure. Space change between stay cables and stable cables has little effects on dynamic characteristics of the structure. Conclusion is that design parameters of the wind-cable structure have great influences on dynamic characteristics of the pipeline suspension bridge. For improving wind resistance of the bridge, these parameters should be selected in a reasonable range.