Research on the Design Parameters of Long-span Railway Concrete Extradosed Bridge

Research purposes: With the rapid development of my country's railways, especially high-speed railways, long-span railway concrete extradosed bridges have become more widely used. For example, the Yingshang Bridge on Shangqiu-Hefei-Hangzhou Railway with a main span of 220 meters, the Apengjiang Bridge on Qianjiang-Zhangjiajie-Changde Railway with a main span of 240 meters, and the Wulongjiang River Bridge on Fuzhou-Pingtan Railway with a main span of 288 meters. Through the research on the design parameters of long-span extradosed bridges at home and abroad, and combined with the impact of key design parameters on mechanical properties, the reasonable values of key design parameters are proposed. Research conclusions:(1) Appropriate structural systems for long-span railway concrete extradosed bridge should be selected according to local conditions to reduce structural deformation, maintenance and repair, and improve driving comfort; (2) The height-to-span ratio of pylon above the bridge deck and main girder for railway extradosed bridge should be 1/8~1/10; (3) The fulcrum depth-to-span ratio of main girder for the railway extradosed bridge should be 1/18~1/20, and the ratio of the mid-span beam height to the fulcrum beam height should be 0.45~0.6; (4)The stay cable safety factor of the railway extradosed bridge is recommended to be no less than 2.0; (5)The research conclusions can provide references for the design of railway bridges. © 2022, Editorial Department of Journal of Railway Engineering Society. All right reserved.