常泰长江大桥专用航道桥吊索环形高阻尼橡胶片阻尼器减振研究OA

[Objective]The Changtai Yangtze River Bridge is a key control project on the Ruchang Expressway and the Changtai Intercity Railway.The main channel bridge features a cable-stayed design with a span of 1 208 m.Two dedicated channel bridges,spanning the Tianxingzhou Reserved Channel and the Luan'anzhou Channel,employ steel truss arch bridges with a main span of 388 m and a maximum suspender cable length of 51.3 m.Long and flexible suspender cables have low lateral stiffness and intrinsic damping,making them prone to vortex-induced vibrations(VIVs).They may also experience wake galloping when located in the wake regions of the adjacent cables and tower,resulting in multi-mode vibrations that necessitate vibration mitigation measures.[Methods]Considering the anchoring design of the cables of the dedicated channel bridges,a solution was proposed to install high-damping rubber dampers at the guide pipe ends near the cable lower anchorage to suppress VIVs.To accommodate installation misalignments between the guide pipes and the cables,as well as the need for cable force adjustments during operation,this study developed an annular high-damping rubber sheet damper that was easy to install and adjust.The damper consisted of standard-sized annular rubber sheets stacked in layers and then mounted using flanges.The flange installation adapted to various alignment conditions between the cables and guide pipes and facilitated easy removal during cable force adjustments.The number of rubber sheet layers was optimized based on the parameters and forces of individual cables and could be adjusted after cable force changes to achieve the optimal vibration mitigation effect.[Results]The developed high-damping rubber sheet damper was tested,achieving a loss factor of approximately 0.25.Further calculations based on damper test results were conducted for the vibration of the suspender cables of the bridge.The results indicated that,after installing this damper,the logarithmic decrement rate achieved the target threshold of 0.01 for vortex-induced vibration control,thus verifying the effectiveness of the proposed solution.[Conclusion]The research methods and results can serve as a reference for similar engineering projects.